Poultry Management:

[mikey]

The ABC of male behaviour
By Ron Meijerhof, senior technical specialist, Hybro B.V. Males play an important role in obtaining a good hatchability, because they are of course crucial in the process of getting fertile eggs.

 

Although it is well known that also female condition can be a significant factor, in case of fertility problems we often look at the males. And most often, that is the correct starting point. If we think about fertility problems, we normally think about factors as semen quality, bodyweight control, physical condition of the males, foot pad quality, etc. Without a doubt, these aspects are important. If semen quality is not optimal because of a disease or a nutritional factor, or if semen quantity is not sufficient because the males lost bodyweight, maximum fertility will not be achieved. If the males lose condition because of overweight or have a problem walking because their foot pad quality is not optimum, it will definitely have a negative effect on fertility. However, there is one more factor that is of utmost importance for fertility.

They have to like each other
The most important factor for a good hatchability is a high number of successful matings. And to be able to have successful matings, not only the physical condition of males and females must be good, but they must also have the will to mate. And as mating is the final result of a complex sequence of social interactions, we have to look at the behavior of the males and females as well, if we want to make sure we have a high number of successful matings. In other words, we have to make sure they like each other.

Male-to-Female interaction
One of the most important aspects in the behavior of chickens is the issue of dominancy and pecking order. A male (chicken) has to be dominant over a female to be able to mate. At the same time, the female should not be scared of the male and try to avoid mating. In a well managed flock, males get dominant over the females just before production starts.

If their dominancy develops too early, the males are getting active before a sufficient number of females is sexually mature, and as a result the males start chasing the females, over-mating occurs, males start fighting with each other, females are getting damaged and scared, and as a final result, fertility is too low.

If their dominancy develops too late, the males will not become dominant over the females and will be scared to mate with them. The males can be physically well developed but will not mate because they think they are not able to do so. And as a result, again fertility is too low.

Male-to-Male interaction
However, there is not only a hierarchy between males and females, but also between the males. Not all males are equally dominant, and some males are higher up in the hierarchy than others. This is often a result of differences in body weight, but is not always necessarily so. If we take a closer look at the flock, we can divide the males in three different groups:

A-males: males that are dominant, high-up in the hierarchy, are willing to mate and will mate.
B-males: males that are not dominant, are not high enough in the hierarchy, but would like to mate and will try to mate if they get the opportunity.
C-males: males that are not dominant, are low in the hierarchy, and are too low in the hierarchy to mate or even consider mating.
Of course this is an arbitrary classification, but it helps us to understand what happens in a flock of males. In an actual flock, all three groups will always be present, but it depends on the condition of the males what the distribution between the groups will be.

It is clear that B-males will be dominant of C-males, and A-males will be dominant over both B and C males. That means that an A-male will try to prevent B-males from mating, although the B-males would like to mate. The problem of a low fertility can be that there are not enough A-males to do all the mating, or that there are enough A-males but they are occupied with other things than mating. Especially if there is high number of males in a flock, sometimes the males are so busy with disturbing each other that the number of successful matings is going down.

Within the flock, it is not only the group of A-males that are mating. Most females will stick for a limited period of time to one male, and that will be an A-male, but some females will move around from male to male, and some females will try to avoid mating by doing that. We can recognize this when we set eggs from individual hens, because we then see that some hens always give infertile eggs and avoid mating. We call these females “loose hens”, and we normally see the number of these hens increasing with the age of the flock. If B-males have the opportunity, they will try to mate with these hens. And the more brutal and brave these B-males are, the more successful they will be in doing so.

Increase fertility
At first sight, the key for a good fertility is a high number of A-males in the flock. What we have to realize is that just taking out the bad males (C-males) will not always solve the problem of bad fertility sufficiently, as by doing this we don’t increase the number of A-males, we just decrease the number of C-males. But the C-males are not the real cause for a bad fertility, because they didn’t mate in the first place. That doesn’t mean we don’t want to select these males out, but we have to realize that these males are not always our biggest problems.

Where we want to focus on is on two different things:
We want to keep the number of active A-males high. Not only should we have enough A-males, but they also should be active, and not only busy with fighting other males.
We want to get the B-males as active as possible, so that as many as possible “loose hens” are mated.
How to manage male behavior in the field?
There are several management tools that we have to take into consideration for achieving these two goals.
First of all we have to look at the male and female behavior, to see how they react towards each other, especially early in production. The best time to look for the behavior is in the last period before the light goes out, as this is the period where the males are most active.
If we look over the flock, we should see the males sticking out over the females as “tulips in a meadow”. This means that the males feel dominant and stand upright, with their backs under an upward angle. If the males don’t stick out 10-15 cm over the females but have their heads on the same height, it means that they don’t feel very dominant, very “macho”, and probably their mating activity will be low.

If we stand in the house for a couple of minutes (especially if we are visitors), males should pay attention to us, and even come up to us. After a couple of minutes, we should see that the females move gradually away, and the males move towards us, so that 1/3 or half of the birds in the direct neighborhood are males. This means that the males see us as intruders in their territory, and they are reacting to that. If males don’t care if anybody comes in their territory, looking for their females, they are probably not that dominant.

The females and males should act “socially” towards each other. If the females try to avoid meeting the males or the males surround and chase the females, they probably don’t like each other that much. If we see this, we should react immediately by reducing the numbers of males, to release the pressure. In early production this often means that we have to get rid of some of the best males, because they are matured too early.
If we rear males in high density (more than 4 birds per m2) they will often run into each other and fight. As a consequence, several males will lose their dominancy and become a C-male already in rearing, because more males will lose fights. If we rear in low density, the males will fight less, and as a result, stay dominant because they never lost a fight.
We have to make sure that the males grow enough early in production, to build up their dominancy. If we don’t allow them to grow or even let them lose weight, they will not be able to keep up their dominancy and will lose mating. Often we see that males become overweight because they are inactive, and not become inactive because they are overweight.
When we select, we should pay attention also on males that act dominant but don’t mate anymore. This can be done by looking at the color and the condition of the cloaca. We should especially examine the males that look dominant, but at the same time are overweight.
When we spike, we have to make sure that the young males have a chance to overcome the A-males. This means that the young males must be mature enough, but that we place enough young males and preferably remove some of the A-males. To select the right males to remove, we have to again look for the dominant A-males that seem to be overweight and have a dry cloaca. Of course we also want to select the non-active C-males, as they are of not much good anymore. If we don’t give the young males a fair chance, they can very quickly be found in the group of C-males.
When we intra-spike, make sure that as much males as possible are moved and mixed between the houses, to break the existing hierarchy.
If we force the males to move a lot through the house, more B-males will mate with “loose hens”, resulting in more mating. This means that we have to centralize the male feeders as much as possible to force the males to move, instead of spreading out the male feeders over the house.
With sex separate feeding we do not only control the male body weight (and with it prevent overweight) but we also make the B-males more courageous and less afraid. This is because we force them to eat together with the A-males every day. It is therefore especially important to not only look at body weight control with sex separate feeding, but also to the location of the feeders. Again, it is important to bring as much males as possible into the same area.
By looking not only at the physical condition of the males but also at the way they act with the females and towards each other, we can learn a lot about their mating activity. After all, if males and females don’t like each other, mating will not happen, no matter how well their physical condition will be.

March 2007

[mikey]

Maximising performance using the broiler breeder’s own agenda
By Ron Meijerhof, Senior Technical Specialist, Hybro B.V. - The technical performance of broiler breeders is influenced significantly by their natural behaviour.

 

Technical results will be adversely affected, for example, if the birds don’t want to enter the laying nest, mate or they are unable to eat all at the same time – regardless of the genetic potential of the birds. So to manage our breeders for optimum performance, it helps to understand the ‘behaviour basics’ that are incorporated into the daily schedule of a chicken.



Creatures of habit
Broiler breeders don’t perform their activities randomly throughout the day. They have a schedule, the most important aspects of which revolve around egg laying and mating, which we must respect through our management practices.



Egg laying
Laying begins about one hour after the light goes on in the morning, with the majority of eggs being produced in a period of approximately six hours. This means that throughout that six hour period, all birds must have unhindered access to the nests.

A broiler breeder will often occupy the nest for about 45 minutes to lay her egg, with around 20-25 minutes to prepare for laying, and another 20-25 minutes to enjoy the result. In warm conditions, birds may occupy the nest for even longer.

If we consider the fact that not all birds lay every day, and that not all nests are occupied 100 per cent of the time, we can calculate at least one hour of nest occupancy for every egg laid, in a laying period of about six hours. This means that at peak production, we need one individual nest per five or maximum six birds.

In a community nest, each laying bird will occupy around 15cm width in the nest – so approximately six birds per metre of nest space. And if each place is occupied for one hour, we can expect to place 35-40 birds per metre of nest length during the six hour laying period. Placing more birds is likely to be counter-productive, as this will make it difficult for some of the birds to find a free space.



Mating
Mating is, of course, a key feature of the breeder’s daily schedule, occurring mainly during the last four hours of light – and with good reason. If mating happened in the morning, the laying of eggs would obstruct mating behaviour, and the outgoing egg would expel incoming semen.

Males are most active during this part of the day, so we must attract the females to the scratch area during this time, as well as observing the mating behaviour of the males, to ensure that they are neither too aggressive nor too docile.



Feeding and drinking
With the first six-seven hours and the last four hours of a 16 hour light so engaged, we are left with only five-six hours during which to plan eating and drinking.

If we provide feed during egg laying or mating, we are effectively asking the birds to choose between staying hungry to use a nest or mate, or to take feed with the risk of producing a floor egg or avoiding mating. And some of our breeders will choose to eat!

Depending on the flock and the feeding system, birds need approx. two hours to eat and four to drink. This means that we should start giving feed and water seven-eight hours after the light goes on, to avoid any conflict with laying and mating behaviour.

Another advantage of feeding after laying, is that the calcium in the feed becomes available for the bird when shell is formed, mainly during the night.

However, if we feed seven-eight hours after lights on, digestion will occur during the warmest hours of the day. This is not a problem in moderate climates, but the heat production associated with digestion can cause problems for birds in hot climates – where to ensure that feeding doesn’t interfere with laying, we must compensate by feeding as early as possible.

Our breeder flocks have a very straightforward approach to life, and therefore to what they need and expect from us. By understanding their behaviour and meeting their expectations, we can ensure that our birds make choices that are in our best commercial interests.

May 2007

[mikey]

Feeding Broiler Breeders for Chick Quality
By Aviagen - For a chick to fulfil its genetic potential as a broiler chicken, it is imperative that it has the best possible start in life.

 

Introduction
For successful broiler production a chick requires good bodyweight, with excellent nutritional reserves at day old. It needs to be in excellent health with a fully functioning immune system. From this starting point, providing the broiler with suitable environment and nutrition will enable optimal performance to be achieved.

The developing embryo and the hatched chick are completely dependent for their growth and development on nutrients deposited in the egg. Consequently the physiological status of the chick at hatching is greatly influenced by the nutrition of the breeder hen.

In reviewing breeder nutrition, it should be remembered that nutrient supply to the broiler breeder is a sum of two parts, namely nutrient content of the diet and quantity of feed supplied to the breeder birds. Both parts need to be balanced to ensure correct daily nutrient supply. It is also very important to realise that the cost of feeding the breeder appropriately to ensure good nutritional status of the chick is very low when viewed on a per chick basis and compared with the total feed cost of raising a broiler to slaughter weight. Calini (2006) calculated that the cost of breeder feed contributing to the production of a chick is equivalent to only 7% of the total feed cost for a broiler grown to 2.5Kg. This illustrates the value of ensuring the best possible nutrition of the breeder.



Nutrient Levels in Broiler Breeder Feeds
When considering nutrient levels in breeder feeds, the nutritionist must focus on the daily supply of individual nutrients to the bird. Starting with protein, studies have shown that the protein levels fed to breeders in production can affect chick bodyweight and final broiler performance. The relationship between protein content of breeder feed and chick weight seems well defined.

 


Using this information, a breeder diet with an energy density of approximately 2750 Kcal/Kg should have a protein content of 15%. This optimum protein level has been supported by other work, and it is important to remember this is an optimum level, not a minimum, as excess protein can be as detrimental as insufficient protein. In particular, it has been shown that excess protein reduces fertility. Furthermore, consideration must be given to protein quality and the nutritionist must ensure a balance of amino acids is supplied from good quality protein sources.

The impact of energy content of the breeder feed is not as well defined as that of protein. Reviewing studies carried out to evaluate optimum energy intake would suggest that 440 - 480 Kcals/bird/day is most appropriate for optimal chick quality. This equates to 160 - 175 g/bird/day at 2750 Kcal/Kg feed. When considering energy, attention must also be given to fat composition and in particular to the requirement for unsaturated fats such as linoleic acid. This essential fatty acid is required for cell membrane integrity, immune competence and embryonic development, therefore directly affecting chick quality. In practical terms, the inclusion of added fats into breeder feeds should be kept low, with preference for unsaturated fats rather than saturated fats.

The major minerals, especially calcium, phosphorous, sodium, potassium, magnesium and chloride are involved in shell formation; improvements in shell quality generally lead to better egg and chick quality. Variations in maternal phosphorous supply have been shown to influence bone ash of young but not older progeny. It is important to supply adequate phosphorus in breeder diets to ensure best possible bone integrity in the early stages of chick growth. In terms of trace minerals, most interest in this field has centred on the use of chelated minerals which have been shown to increase deposition in the egg and transfer to the tissues of the hen and the embryo. Most recent work has focused on the antioxidant status of breeders, embryos, offspring and the role of selenium. Seleno-methionine has been shown to improve both the vitamin E and antioxidative status of eggs, embryos and chicks up to 10 days of age. Supplemental zinc methionine and manganese amino acid complexes have shown improvements in chick immunity and liveability.

Table 1 is a summary of those minerals which when fed to breeders have an effect on progeny performance.

Table 1. Summary of minerals fed to breeders shown to have an effect on progeny performance.
 
 
 Growth
 Liveability
 Immune Function
 Skeletal
 
Fluoride
 
 
 
 X
 
Phosphorous
 
 
 
 X
 
Selenium
 
 X
 
 
 
Selenomethionine
 X
 
 X
 
 
Zinc
 X
 
 X
 X
 
Zn-Methionine
 
 X
 X
 
 

Vitamins are involved in most metabolic processes and are an integral part of foetal development, therefore the consequence of suboptimal levels of these nutrients in commercial diets are known to result in negative responses to both parent and offspring performance. Vitamins account for about 4% of the cost of a breeder feed, so economising on vitamin inclusion rates is rarely a sensible option. Generally there is a shortage of information on vitamin requirements of broiler breeders especially when related to offspring performance. Most of the breeder work is quite dated and since that time breeder performance has changed.

A review of work on fat soluble vitamins, biotin and pantothenic acid has shown that vitamin E has the largest impact on progeny. In general it seems to be justified to supplement practical breeder feeds with 100 mg/kg vitamin E.

The influence of increased vitamin levels fed to young parent stock on progeny performance is an area which has received significant commercial interest. Internal and field trials have shown that increased vitamin levels (mainly B Vitamins and Vitamin E) improved liveability and early growth. A practical basis for making recommendations is to feed vitamin levels that maximise the resulting level in the egg.



The Influence of Feed Allocation on Chick Quality
Underfeeding the hen can have an impact on chick quality and this is particularly noticeable in the early production period. Modern hybrid parent flocks commence production at a faster rate than in the past and consequently egg output increases over a shorter time span during the early laying period. Feed allocations during this period have not necessarily increased in line with this egg production trend. Low feed allocation intake by young commercial breeder flocks have been shown to compromise nutrient transfer to the egg, resulting in increased late embryonic death, poorer chick viability and uniformity (Aviagen Ltd 2002). In a study by Leeson (2004) broiler breeders were fed different levels of feed through peak production varying from 140 to 175 grams. Although the increased feed allocation increased bodyweight there was no influence on egg size up to 175g, however chick weight was influenced by feed allocation. See Table 2 below.

Table 2. The effects of breeder feed levels on chick weight

 
 
Peak breeder feed (g/b/d)
 30 week breeder chick weight (g)
 
140
 40.3
 
147
 40.0
 
155
 41.5
 
162
 41.7
 
169
 41.8
 
175
 42.0
 

Summary
Research shows that nutrient supply to the broiler breeder is of consequence to chick quality and production performance. This places greater emphasis on the nutritionist providing the correct nutrient density diet and the flock manager to provide appropriate feed intake to the bird coming into lay and through the production period.



4 Key Points
Breeder Nutrition influences chick quality and broiler performance


Broiler performance can be economically improved by investing in breeder nutrition


Supply diets with adequate and consistent nutrient levels to breeders


Manage feed quantities with reference to breeder physiological requirements, productive status and bodyweight
March 2007

[mikey]

Salmonella control: protecting eggs and people
By Brian Sheehan and Rick van Oort, Intervet International, Boxmeer, Netherlands. Published in World Poultry.

 A European Food Safety Agency (EFSA) study recently showed that the percentage of layer flocks infected with Salmonella is still very high in some countries. Many EU member states therefore have to increase their efforts to reduce these levels. Vaccination is an important tool in a Salmonella control programme.

The recent EFSA study on the prevalence of salmonella in laying hens showed that, despite many efforts to reduce the incidence, many European countries still have a high percentage of Salmonella enteritidis (Se) and Salmonella typhimurium (St) positive layer flocks.

 The cornerstones to reduce the number of salmonella positive flocks are strict hygiene, decontaminated feed and improved poultry management. Re-infection with Salmonella could also take place via other sources such as rodents, wild birds and visitors.

Another important tool to reduce the incidence of salmonella in poultry is vaccination. The salmonella vaccines currently on the market can be categorised as either live or inactivated. Their use will be determined by their individual features, benefits, and end market requirements.

Live salmonella vaccines, as the name suggests, contain live attenuated strains of salmonella serotypes. Individual products are available that protect against either Se or St, so the first question is against which serotype protection is required.

Some European countries require compulsory vaccination against Se and St.

[mikey]

Rearing Parent Stock
By Johnny Harrison, Technical Service Manager, Aviagen Limited - This article follows the life of a flock of Aviagen parent stock birds, focusing on the rearing period, 0 - 6 weeks, (0-42 days).

 
Aviagen produce a range of genotypes suitable for different sectors of the broiler market and all Aviagen products are selected for a balanced range of parent stock and broiler characteristics. To achieve the best possible outcome, and to meet the needs of your operation, the best possible start must be provided to both the male and the female parent. Fulfilling all of their requirements during the rearing period will prepare them for sexual maturity.

Aviagen parents have the same growth and feed efficiency characteristics as the broiler generation, so growing the Aviagen parent to the target growth curve allows both males and females to achieve optimum lifetime breeder performance. The principles for managing males and females in the rearing period are the same, even though the target body weights are different. Although males constitute a small percentage of the flock in terms of bird numbers, they will form 50% of the breeding value. Males are therefore just as important as females; however throughout the rearing period the management of males will require more effort to achieve success.

Managing the available feed is crucial in ensuring even distribution to all of the birds and this is one of the main management challenges during rear. Managing the birds' growth rate so they achieve the target bodyweight for age is maintained through accurate control by sample weighing at least twice a week until grading and adjusting feed allowances accordingly. As a result accurate grading will aid good uniformity.

HOUSE PREPARATION

FIGURE 1: Bird Distribution under Brooders 
As outlined in the Biosecurity article (Zootecnica Russian Edition, Feb/Mar 2006), houses and equipment must be cleaned, disinfected and set up in time for the brooders to be started and temperatures to reach the desired level 24 hours before the chicks arrive. The house should be checked to ensure that it is adequately light proofed. Birds are very sensitive to day length and any accidental seepage of light should be corrected immediately. Match the times when house lights are on to the natural day light as far as possible to limit the impact of poor light proofing. Problems such as early on set of lay, broodiness and prolapses or delayed production may result from poor light proofing of the rearing house.

Temperatures should be checked at chick level. If insufficient time is allowed for floor temperature to reach house temperature, there is a danger that the chicks will become chilled. Chick behaviour is the most important indicator of temperature, farm managers and farm staff must respond quickly to changes in chick behaviour. The photo right demonstrates chick distribution.

Fresh litter, free from dust, should be laid to a depth of 10cm. Where floor feeding is in use litter depth should not exceed 4cm as feed will be lost in the litter. Good quality litter will reduce the risk of the chicks eating the litter.

BROODING AREA PREPARATION
There are two basic systems to supply heat to the birds:

Spot Brooding
Warm air/Whole House Brooding
Brooding down the centre of the pen is most likely to achieve uniform chick distribution. Figure 2 shows a typical spot brooding system for 1000 day old chicks. When planning chick placements, it is advisable to brood chicks from young donor flocks separately for the first 14 to 21 days, this will prevent early competition when birds are unequal in size.

On both systems chicks must be placed in the brooding area immediately after they arrive. Full chick boxes should never be stacked within the brooder house as this can cause heat stress. Empty chick boxes should be removed from the building and destroyed as soon as possible. To avoid undue stress vaccination should take place in the brooding area after the chicks have settled in.

The brooding area should be designed to allow the chicks access to a plentiful supply of fresh feed and water upon arrival. Birds given immediate access to feed and water have been shown to have better early growth and uniformity than birds in which feeding was delayed.

A maximum of one day's supply of feed should be provided daily to avoid problems associated with stale food. Chicks should be treated as broilers for the first 5 to 6 days (i.e. fed ad libitum). Feed should be given frequently (i.e. 5-6 times per day) to stimulate appetite.

A plentiful supply of water must be provided, use supplementary drinkers as well as the drinking systems already fitted in the house. Aviagen does not recommend the addition of glucose to drinking water as it can depress appetite and cause dehydration; the goal we are aiming for is developing healthy appetite and drinking behaviour

For the first 24/48 hours light should be continuous, with a light intensity of 100 lux. To encourage even distribution of chicks, the brooder light should be raised initially, followed 2-3 days later by switching on the adjacent rows of house lights.

The principles for whole house brooding are basically the same, but it is less easy to use chick behaviour as an indicator of satisfactory temperature than with spot brooding, because there are no obvious heat sources. By spending time in both environments you will notice a different noise made by the birds, this may be the only indication of distress. The birds will congregate in the areas where the temperature is closest to their requirements. Some care is needed to interpret chick behaviour.

Chicks must have an adequate supply of fresh air and a minimum ventilation program must be established during brooding. It is good practice to establish a system of minimum ventilation during brooding.

Monitor relative humidity (RH) levels in the first 3 days and aim to achieve around 70%. If humidity falls below 50%RH in the first week, chicks will begin to dehydrate, causing negative effects on performance. In such cases, take action to increase humidity. Various methods of humidification are suitable, from spray systems designed to cool birds in hot weather to simple open water surfaces. Keep the system clean, because it can provide a very effective means of transmitting bacteria.

REARING FROM 0 - 4 WEEKS (0-28 DAYS)
The aim in this period is to ensure good early development of skeletal size, immune system, cardiovascular function, feather growth and appetite. It is important to obtain the best possible uniformity to reduce the amount of size grading required later in the flock.

To maximise performance birds should be on or over target bodyweight by 7-14 days. Flocks that fail to achieve target tend to lose uniformity. Bodyweight targets in the early stages of rearing can only be achieved by ad libitum feeding of a good quality feed from day old, Crop fill should be assessed to ensure that chicks are developing a healthy appetite and achieving good early bodyweight and skeletal growth, see figure 4.

A full crop will be a rounded mound and it should feel like pea soup, a mix of water and feed. Aim for more than 95% of birds with full crops by 8 hours after first access to feed and water, and more than 99% at 24 hours.

If there is any evidence that birds are not growing to target bodyweight, then the age at which constant day length will be achieved can be delayed

BODYWEIGHT AND UNIFORMITY
It is essential to monitor growth and development in a flock by weighing an adequate sample of birds and comparing them with the target bodyweights-for-age. The birds must be weighed accurately using conventional mechanical, dial or electronic scales are more labour intensive, but using these systems enables you to handle each bird and check its condition as well as its weight.

Sample weighing should be carried out twice weekly starting at day old; randomly selected samples of birds should be weighed individually. Groups of 50 to 100 birds per colony should be caught using catching frames and individually weighed. All birds rounded up as a sample must be weighed in order to eliminate any bias. Birds should be weighed on the same day each week and at the same time, preferably 6 hours after feeding

CONTROLLING BODYWEIGHT
Bodyweight can be corrected by adjusting feed allowance. This can either be maintained or increased. Feed allowances must never be decreased during the rearing period. Adequate feed space must be available and feed should be distributed in less than 3 minutes per colony. Good feed distribution, which allows all the birds to have access to feed at the same time, is absolutely essential because the birds are fed at less than ad libitum.

Birds must be fed every day until grading has been carried out. After grading an alternative method should be considered to ensure even distribution of the feed, minimising competition and maintaining bodyweights and flock uniformity. 'Skip a Day' can be used. This is achieved by accumulating sufficient feed on the 'feed day' and supplementing with a scratch feed on the intermediate days.

GRADING TO MANAGE UNIFORMITY
Uniform flocks will be much easier to manage than an unequal one, because the majority of the birds will be in a similar physiological state and will respond to changes in levels of feed or light when necessary. A uniform flock will react predictably to increases in feed and will produce good results consistently. Flock uniformity can only be achieved by applying high standards of management in the first 4 weeks.

Grading is best carried out when the flock is aged 28 days (4 weeks), at which time the uniformity of the flock is usually within the range 10-14%. If undertaken later than 35 days (5 weeks) the time available in which flock uniformity can be restored, i.e. up to 63 days (9 weeks) becomes too short. In most cases, grading will be undertaken when the flock CV% is around 12.

The practical requirements of grading must be considered at the planning stage, before the stock is placed. The easiest way to grade is into pens or possibly houses which have been left empty at placement for this purpose. To establish successful grading the flock should be sorted into populations of different average weight at 28 days (4 weeks) of age, so that each group may be given the management during the rearing period, which will result in good whole flock uniformity at point of lay. As an example, separating 10,000 females into 4 groups of 2500, less any mortality, will give one group of small birds, two groups of medium birds and one of large birds. The males should be divided into two colonies as it is easier to manage small colonies.

Within the flock to be graded all colonies must be sample weighed and all the individual weighings should be consolidated into a single distribution. Two-way grading is preferable, provided that the flock CV% is less than 12 at grading. If the CV% is more than 12, then a 3-way grading will be required and management practices from 0-4 weeks should be examined closely, so that improved CV% can be achieved with subsequent flocks.

Flock CV% should be calculated. Cut-off points must be set to achieve consistent stocking densities allowing for differences in pen size. Table 2 indicates the typical percentages in light, medium and heavy populations to achieve populations with CV % less than 8 for 2 or 3-way grading. Bird weight cut off points should be set to achieve the required percentage of the population in each colony

All birds must be handled and allocated to their correct category to achieve accurate grading. It is strongly recommended, for reasons of efficiency and accuracy, that all birds should be weighed.

Birds must be counted accurately in order that the correct quantities of feed are provided. Stocking density per colony, and therefore feed and water space must have been routinely adjusted when the moveable partitions were positioned. In addition feeding space, speed and uniformity of feed distribution must be adequate.

Each category should be reweighed to confirm the average bodyweight and uniformity so that its projected target bodyweight and feeding rate may be determined.

Key Points:
Prepare, clean and disinfect houses and equipment well in advance of chick arrival.
Ensure that the house reaches the correct temperature and Relative Humidity 24 hours before chicks arrive.
Ensure that chicks have immediate access to fresh water and feed.
Monitor crop fill to ensure chicks are feeding.
Use chick behaviour as an indicator of satisfactory brooding temperature.
Achieve early bodyweight targets to facilitate successful rearing.
Start sample weighing at day-old.
Weigh birds at the same time each week, twice weekly.
Use accurate bird weighing equipment.
Never decrease feed allowance during rearing. Feed allowance should either be held or increased.
Give birds the correct feeding and drinking space.
Feed should be distributed in no more than 3 minutes per colony.
Grade into 2 colonies if CV% is less than 12; into 3 colonies if CV% is greater than 12.
After grading, each colony should have a CV% of 8 or less.
This article was first published in Zootecnica Russian Editon, April/May 2006

[mikey]

Defining and measuring quality in day old broilers
By Ron Meijerhof, Senior Technical Specialist, Hybro B.V., Boxmeer, The Netherlands - The quality of the day-old chick is important not only for minimising mortality in the first days of life, but also as an indicator of final performance.

 
This means that incubation must not only produce as many chicks as possible, but they must be of superior quality to contribute to commercial success.
However the concept of ‘quality’ is often subjective. Every hatchery manager has his or her own definition of what constitutes good chick quality, which can be difficult to describe – and even more difficult to measure.


Visual score
While visual scoring, ie. as ‘good’, ‘average’ or ‘poor’, is highly subjective, it is nonetheless a relatively accurate indicator of chick vitality. Visual scoring measures:

Colour: a deep yellow colour is favoured over pale (light yellow to white).
Development: a large, well developed, long feathered chick is considered ‘better’.
Navel quality: well closed navels reduce the risk of infection and mortality.
Vitality: alert, healthy chicks will find feed and water more quickly.
Although an experienced hatchery manager may be highly accurate in his or her visual scoring, this system is devalued by being prone to personal interpretation and difficult for other personnel to reproduce.


Tona or Pasgar score
The University of Leuven recently developed the Tona score, which was adapted by Pas Reform to create the simpler and more practical Pasgar score. Both methods apply a standardised scoring system across a range of criteria, including chick viability, yolk sac uptake, navel closure, and the ability of the chick to recover after being placed on its back, for example.

Both methods create a consistent, measurable data-set that can easily be repeated. And while the relationship between Tona- or Pasgar score and broiler performance has not yet been proven, it appears likely that there is a valid correlation to first-week survival.


Day old chick weight
Although easily recorded and repeated, day-old chick weight has limited value as an indicator of overall quality, as it is correlated with egg weight rather than chick development. This is because day old chick weight includes both the actual chick weight and the weight of remaining yolk residue. Yolk-fat is fuel for embryonic development, so if a lot of yolk remains, less development has occurred and chick quality is likely to be undermined.


Yolk free body mass
Yolk free body mass (body weight without residual yolk) is a better indicator of chick development, especially when corrected for initial egg weight . However, measuring in this way is a costly and labour intensive process. 

Chick length
Measuring length from the tip of the beak to the middle toe is a more practical way to determine chick development. Hybro’s research has shown that measuring the length of a chick is a dependable indicator of development and a better indicator of broiler performance than day-old chick weight, especially when corrected for egg size.


Choosing a scoring method
The Tona- or Pasgar score and chick length have clear advantages in terms of repeatability, practical application and their relationship to chick quality. However, it is important to note that these two methods are taking different measurements.
As hatcheries are often accountable for first week mortality, the Pasgar score is useful in this environment, as hatcher conditions determine navel closure, yolk uptake and vitality – and therefore the condition of the day-old chick and its ability to thrive in the first week.
Chick length deals more with development, which is related to conditions in the setter, and has less influence on first-week survival but more on performance during grow-out. This method is therefore recommended for total integrations whose bottom-line is determined by broiler performance.
A combination of the two methods, with ± 75 per cent of the final score based on broiler growth potential (chick length) and the balance based on survival rate in the first week (Pasgar score), provides optimal measurement of chick quality.

This column was published in International Hatchery Practice Volume 19 Number 7, 2005

Source: Hybro B.V. - June 2006

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Brooding Temperatures for Small Poultry Flocks
By the Manitoba Agriculture Food and Rural Initiatives - This report looks at the ideal brooding temperatures for hatched chicks.


 A hatched chick cannot maintain a proper body temperature without your help. Exposing a chick to cool temperatures in the first three weeks of life makes the bird uncomfortable and less likely to eat the feed and drink the water needed for a good start. In meat-type chickens, cool temperatures can lead to permanent heart damage. Exposing the young bird to cool (20°C or 70°F) for the first day or two on the farm can cause the bird to die from heart problems later. Heated premises are definitely needed for brooding.

For small flocks, the most common source of heat is a heat lamp. These lamps accommodate a 250-watt red or clear bulb. When suspended 45 to 60 cm (18 to 24") off the floor, they provide enough heat to brood up to 100 chicks for a single-light, or 300 to 500 for a four-light model. Some units have thermostatic controls, while others have to be raised or lowered to provide the required temperature at bird level. As the birds grow older, lower the temperature by raising the heat lamp or reducing the wattage of the bulbs.

Turn the heat on at least one day before the birds arrive on the farm. The temperature 1 cm (½ ") below the litter surface should be at least 26°C (80°F). Even if the air is the correct temperature, the birds can be chilled by the cold floor under them.

 Temperature on the floor, at the edge of the heat source, should be 32 to 35°C (90 to 95°F) for the first week. As long as the temperature at the edge of the heat lamp or brooder stove is this warm, the air temperature 2m (6') away from the heat source can be as low as 28°C (82°F). The birds can then chose where they feel most comfortable. If you cannot maintain a hot point next to the heat lamp, an average air temperature of 30 to 31°C (85 to 88°F) is suggested. The temperature should be reduced by 3°C (5°F) per week, until the room temperature of 20°C (70°F) is reached. After six weeks of age, temperatures in the 18 to 21°C (65 to 70°F) range are desirable.

Some hatcheries will sell a 30 to 45cm (12 to 18") high corrugated cardboard that can be used to set up a brooder that forms a circle around the heat lamp. The ring helps protect the birds from drafts and piling in corners. For 300 birds, you might use a ring 3m (10') in diameter.

Judging Bird Comfort
 The behavior and sounds of the chicks will indicate their comfort level. Comfortable birds will form a circle under the lamp, and make soft "cheeping" noises; cold birds will huddle and pile, and make sharp noises. If birds are too hot, they will crowd as far from the lamps as possible. Some birds will pant if the temperature is too high. Your birds will do a better job than a thermometer of telling you if they are comfortable. The diagrams below show how birds will move away or towards the heat lamp if they are hot or cold.

Warm Room Brooding
Some people heat their barns with space heaters or hot water pipes. Without a heat lamp or brooder stove to act as a hot point, the birds cannot move towards or away from the heat source to regulate their body temperature. As a result, it is more difficult to judge bird comfort when you warm room brood. Comfortable birds will be spread out and making full use of the pen. Cold birds will tend to bunch together, sometimes near the walls. Hot birds may also gather around cold, outside walls. Panting is a sign of heat stress.

Source: Manitoba Agriculture Food and Rural Initiatives - May 2006

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Guide for Prospective Contract Broiler Producers
By Dan L. Cunningham, Department of Poultry Science, The University of Georgia - Georgia ranks as one of the top poultry growing areas in the United States, producing more than 7 billion pounds of chicken meat annually.


Introduction
Georgia ranks as one of the top poultry growing areas in the United States, producing more than 7 billion pounds of chicken meat annually. The state's broiler industry has experienced impressive rates of growth since the 1950s. During the 1980s and 1990s, it was not unusual for this industry to grow at annual rates of 5 -7 percent, leading to the addition of many new production facilities. In recent years growth has been in the 3-5 percent range because of the economic downturn experienced in the United States and world markets. As the economy improves, growth of the broiler industry should recover as consumers continue to demand this high quality, inexpensive food item. As a major supplier for U.S. and world markets, Georgia will continue to benefit from this important agricultural industry.

Because of the unique structure of contract poultry farming and its long-term investment, new broiler producers should understand its financial and managerial requirements before they commit resources to this endeavor. The information in this bulletin will help those considering poultry production as a new enterprise.
Structure of the Broiler Industry
The broiler industry is rapidly changing and highly technical. It is "vertically" integrated, meaning that all or most production aspects are owned and controlled by an individual company called an "integrator." Integrators usually own the breeder flocks, hatcheries, feed mills and processing plants and contract out the growing and egg production flocks to farmers. The integrator provides a contract producer with the chicks, feed, medication and technical advisors to supervise farm production. Under this system, the company retains ownership of the birds and expects producers to grow their flocks under very specific management programs. Company field representatives normally visit farms weekly to assist with management, but they may do so more often if necessary.

Vertical integration reduces product costs through coordinating and professionally managing each production stage. This approach not only improves cost efficiency, but permits the production of more uniform birds in large volumes necessary to successfully compete in the market. In this system, the integrator is responsible for all processing facilities, processing labor and salaries, and marketing activities crucial to the success of the poultry business. Processing and marketing are very specialized and require considerable expertise and experience for success. For this system to work effectively, integrators and producers make significant contributions to the process and depend on each other.
Broiler Production Contracts
It is virtually impossible to be in the broiler production business today without contracting with a poultry integrator. Production contracts are written legal agreements between integrators and producers defining the terms and conditions affecting producer payments for production of poultry. In the contract system, the producer provides land, labor, housing and equipment, utilities and litter. In return for these production inputs, producers receive a payment based on pounds of live birds produced. Also, contracts usually provide bonus incentives for superior bird performance. Most integrators use a competitive system that ranks growers based on an average production cost per pound for all flocks sold during the same week. Above average producers receive above average payments while below average producers receive less. The contract system has ad-vantages and disadvantages. One of the key advantages for producers, however, is the shift of a significant portion of production and market risk to the integrator. Contract poultry producers are somewhat insulated from price fluctuations in the poultry markets and, since they do not own the birds, have less capital at risk. Prospective producers should understand there are risks as variations in bird placements, size of birds produced, performance and disease problems can cause fluctuations in producer incomes and profit.
Financial Considerations
Costs for broiler production facilities represent substantial investments for producers. Costs for new housing including site preparation, construction, equipment, wiring and plumbing often exceed $170,000 per house. Generally a minimum of two houses is required to make a production unit, but farms consisting of four or more houses are the norm. An average producer can easily have a $600,000 or more invested just in housing and growing equipment.

Prospective producers should understand that poultry houses are long-term investments. Although construction and equipment loans are usually amortized over 15 year periods, the physical life of the broiler house structure can be as much as 30 years or more if it is well maintained. The life of equipment is much less and it is replaced periodically as it becomes worn or obsolete. The history of the poultry business is one of rapidly-changing technology, so producers can expect that significant upgrades will be necessary during the life of the production facility. Staying current with new technology is generally required to maintain competitiveness and the long-term value of the production facility. This is true not only for poultry, but for most any business enterprise that is going to be successful over time.

Broiler production facilities generally range from 20,000 to 25,000 square feet in size. Depending on the weight of the bird produced and the number of flocks per year, gross income for average performance producers for a 20,000 square foot broiler production facility may range from $34,000 to $40,000 annually. Annual fixed and cash costs per broiler house can range from $28,000 to $30,000, depending on type of house, interest rates and mortgage structure. Thus, cash returns to an average producer's land, labor and management per house are generally moderate ($6,000 to $12,000 per year) during the 15 year mortgage payment period. During this debt retirement period, most producers will need additional sources of income for living expenses while equity in the poultry house is being accumulated. It is important to keep in mind that, in addition to the cash returns, producers also receive returns from their houses in the form of accrued equity. The ability of poultry farmers to obtain financing and build assets over time by virtue of the stability of income provided by contracts is one of the benefits of this system. Once the facility is paid for, cash returns per house become much more substantial and may then be in the range of $22,000 to $25,000 annually. Many factors can affect the cash flows and profitability for broiler farms. Some producers will do better at times while others may not do as well. The figures presented above are intended as a guideline to provide an example of what an average producer might expect to achieve. More detailed information on costs and returns for broiler operations is available through other sources (see recommended reading list).
Steps before Building
Meet with poultry company personnel and other producers to discuss the business aspects of contract production. Study contracts carefully and be sure you understand all aspects of contract production. Realize that you cannot depend on being an above average producer every flock. Flock performances vary even with good management, and individuals will sometimes need cash reserves or other sources of income to cover low pay periods. The financial fluctuations associated with poultry production are, however, generally less than for other agricultural commodities and represent one of the key factors in the stability of this enterprise.
An agreement with a poultry company to grow chickens will be necessary before financing or building of production houses can begin. Generally, companies require new production facilities to be in close proximity (25 to 35 miles) of complex operations such feed mills, processing plants, or hatcheries. This reduces expenses of feed delivery, chick delivery and live haul to the processing plant. Experience with growing chickens is not absolutely necessary for obtaining a contract, but certain producer characteristics ( see summary) may be essential.
Meet with lending agencies to determine the availability of financing, interest rates, and payment schedules. Make realistic cash flow projections to determine feasibility of meeting financial obligations. Producers need to consider the consequences of below-average performance as well as average and above average projections.
All new construction must meet state and local laws regarding zoning and environmental impact. Discuss building plans with appropriate authorities before proceeding. Poultry facilities must conform to industry and company standards. House design and equipment recommendations vary by company preference, and their technical representatives will provide detailed information for new buildings. It is recommended that the most current and widely accepted house design and equipment be chosen to allow the producer the option of growing for other integrators in the future.
In some cases, purchasing an existing production farm is a good way to enter the business. This approach also needs careful consideration before making a commitment. Location of the farm, condition and age of the housing and equipment, and purchase price of the farm are very important. Potential buyers should obtain the contracting company's thoughts on the future and productive potential of the farm and what improvements, if any, would be necessary for the company to continue placement of birds in the facilities. Potential buyers should keep in mind that cash flows from the poultry facilities may not be enough to support the purchase of non-production related assets such as dwelling house, barns, trucks, tractors, etc.
Management and Flock Care
Poultry companies have very specific management programs that producers are expected to follow as part of their contractual obligation. To ensure proper management, companies provide field service representatives to work closely with producers on a regular basis. Producers and company field representatives work together to implement best management programs and achieve the highest flock performance levels possible. This benefits the company as well as the producer.
Maintenance for buildings and equipment is a constant job. As houses and equipment age, maintenance requirements for production facilities generally increase. Producers need to handle as much of the maintenance and repair work as possible, since hiring this type of work can be expensive and can substantially increase the cost of farm operation. Preventive maintenance on ventilation, feeding and watering equipment is essential for extending the productive life of these systems and must be done routinely.
House preparation prior to receiving birds is a very important producer management function as the first few days are critical to flock performance. Such preparation includes cleaning and disinfecting the house, spreading litter, setting up brooders, preheating the broiler house to the proper temperature, and being sure feeding, watering and ventilation systems are working properly. Establishing a good brooding environment before chicks arrive is more likely to ensure a successful flock.
Once birds are placed, a considerable amount of time is required for flock management activities such as collecting and disposing of mortality; keeping flock records; monitoring feed, water and environmental control systems; as well as observing for possible health problems. These activities must be done each day throughout the production cycle, but they generally require more time during the critical first two weeks of brooding. Any problems with the flock should be reported immediately to the company representative.
Disease prevention and control are important flock management factors. To protect the flock, access to the poultry house must be limited to authorized personnel. Producers should avoid visiting other poultry farms and eliminate any contact with other poultry, especially hobby, exhibit and backyard flocks. Decisions related to medications of flocks for disease problems or vaccination programs for disease prevention are company responsibilities and are done only as prescribed by company representatives.
Producers are responsible for disposal of all dead birds according to state approved methods. In Georgia, several disposal options are generally available to producers. The more common methods include burial pits, composting, incineration and rendering. Company representatives or local county extension agents can advise producers on the most appropriate methods for their situation.
Producers are responsible for maintenance of grounds and access roads around poultry houses. Keep weeds and grass mowed to reduce rodent and other pest problems. Areas around houses need to be well drained and roads need to be maintained for easy access to feed bins and load-out areas.
Do not use chemicals, pesticides, herbicides, insecticides, vaccinations or medications in or around poultry houses without company approval.
Other Considerations
Consumer demands and market conditions can change company production and marketing strategies. Changes in company strategies in these areas can cause changes in bird placement schedules and sizes of birds grown. These situations can and do cause variations in producer income. Producers should, therefore, be prepared to periodically experience lower than expected incomes from their production units.
Environmental management practices related to litter utilization, dead bird disposal, air and water quality, dust, odor, and pest control are very important aspects of maintaining a viable poultry operation. Current management practices can generally handle these concerns for most farms. Poultry producers should understand, however, that environmental pressures on agriculture are likely to continue and may lead to increased costs of business for both producers and integrators.
Disposal or utilization of poultry litter is a major consideration for poultry farms. Broiler houses generally produce 130-150 tons of litter material annually. In Georgia, most of this material is used as a fertilizer and soil amendment. Producers are, encouraged to develop litter utilization plans before building houses to ensure environmentally sound application or disposal of these products. Company representatives or University of Georgia extension personnel can help with these plans.
Additional equipment such as a tractor with a front loader, a manure spreader, a truck or other specialized equipment may be necessary depending on the size of the operation and the type of management plan employed. Additional expenses for these pieces of equipment may need to be factored into budget projections.
Vacations and time off have to be scheduled around production cycles. Once birds are placed in the houses, they require constant care and management. Achieving good performance levels and above average pay out requires attention to details, and most producers feel they must remain close to their farms during this period.
Develop and maintain friendly relations with your neighbors. Offering to supply manure for a garden plot each year or some other benefit can go a long way when their support is needed.
Summary
Contract poultry production has been a good business for many Georgia farmers. Growing chickens, however, is not for everyone. Before deciding to become a contract producer, determine whether or not you possess the attitudes and capabilities to be a successful producer. A prospective producer needs the following attributes:
A desire to raise chickens.
The financial capability to build housing.
Adequate land for placing the house and disposing of litter.
Adequate and dependable labor.
A willingness to meet contractual responsibilities.
A mind for business.
An open mind to accept technological changes.
A willingness to work within an integrated approach to production.
Once you decide you are interested in contract production, contact companies within your area to determine if they are interested in adding new producers. Get copies of the companies' specifications for buildings, equipment, scheduling and contracts. Discuss broiler production with company representatives. Do not invest in land, buildings or equipment until you have written assurance from a broiler company that you will be provided a contract.

Visit producers who are currently contracting with the company in which you are most interested. If possible, work with an experienced producer for a few weeks to determine if you are suited for the type of work and hours involved. Before building, design a litter utilization and dead bird disposal plan to meet your production plans and farm situation. Keep in mind possible expansion plans for the future of your farm. Talk to your neighbor about your decision. Do you have their support or will neighbors become a major problem?

Talk to local authorities regarding any zoning restrictions or ordinances that might affect your plans. Discuss your plans with lending agencies to determine potential for financing. Visit and discuss your plans with your county extension agent and extension poultry scientist. Obtain copies of extension publications on broiler production and management from your local county extension office or the Department of Poultry Science, The University of Georgia (see recommended reading list).

Making a good decision on broiler farming depends on obtaining as much information as possible. The more people you talk to, the more knowledgeable you will become. Broiler production today requires a substantial investment of funds as well as a major commitment to a life style. It can be an enjoyable and rewarding lifestyle if the decision is made with the appropriate knowledge.

Source: University of Georgia - Cooperative Extension - April 2006

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The Management of Male Breeders
By Lindsay Broadbent, UK Customer Account Co-ordinator, Aviagen - The objective in managing male breeders is to rear sufficient good quality males to mate with females at 19 weeks and thereafter maximise fertility through the lay period. Good quality means that males have the potential to maintain high levels of fertility through the production period. Sufficient will mean anywhere between 8 and 10 percent of the female number at 23 weeks.

 
From evidence we have collected in the UK and other information available, the emphasis on managing the male breeder has changed from a blinkered view of absolute weight profile to a combination of weight profile, skeletal size, uniformity, body condition and mating ratio.

The key message is that weight and feed profile increase from day old to depletion. The weight profile in lay has been modified to ensure that the correct growth rate is more easily achieved and to ensure that body condition is not compromised with age.

Early Growth
It is important that the chicks start well, a good quality starter crumb to 14 days then a starter pellet through to 6 weeks. Weight targets must be met through 7, 14, 21 and 28 days if the birds are to develop good early frame size, feather cover, cardio vascular and immune systems (Fig. 1). A sound skeleton set here will be the building block for the mature male in the breeding house. If weight profiles are met by 28 days, the uniformity will be maximised and the requirement for grading in the following weeks will be minimal.






It is good practice to select the candidates for mating up at 5 weeks. Selection here for a tight population of 100% evenness (CV of 5-7%) to carry forward to the breeding house, plus a few spares for unforeseen losses. Any birds with leg or skeletal defects should be removed here along with undersized and poorly feathered birds. Maintaining uniformity from this point requires the correct stocking density, feed space and feed allowance. If required a second grading at 10 weeks may prove useful. But after this time there is no benefit in grading as the skeleton is 85% grown and leaves no opportunity for the manager to influence skeleton size further.

Stocking density in the range of 3-5.5 birds per m2 is optimal. Feed space from here on must increase up to 10cm per bird if fixed systems are used, then to 15 cm by 10 weeks and 18 cm at 15 weeks.

From 10 weeks, it is critical that you do not lose impetus in growth rate. Development of the sertoli cells begins around this time and testes development continues through to sexual maturity at 23 weeks. From 15 weeks there is rapid development of the testes and growth profiles must be followed or fertility will be delayed or lost. (Fig. 1)

Because of the continuing selection for feed efficiency in male lines, you may need to use a more dilute, bulky diet to increase feed volume in mid rear to ensure adequate intakes of nutrients needed for correct growth and development.

Before transfer to the laying house, the final selection of males must be made. The selected males will be uniform with an upright posture and have grown to the correct profile. Males with leg or skeletal defects, sharp, hooked, short or uneven beaks must also be rejected as either mating will be unsuccessful or injury to the females will occur. The stage of development should be matched as closely to the females as possible using comb, wattle and feather maturity as indicators.

It is best practice to move the males to the laying house 24 hours before the females. This helps the males find feed and water more easily, critical if the growth profile is to continue on track. The males must be fed to follow the growth profile through to 30 weeks to ensure sexual and physical maturity. (See Fig. 2)






Loss of growth rate here will delay early fertility and adversely affect late fertility. By 24 weeks I would expect males to be on 135 g of feed per day, increasing by 1 g per week through to depletion. But maintaining the weight profile is paramount, feed levels will depend on nutritional values and efficacy of the separate feeding system

It is important here to remind you that male feed space should remain constant, with feeder space removed as male numbers go down. This will prevent an uneven population of males developing.

The management principles and procedures used to manage males in the post-peak period are similar to those used in the pre-peak period. Male weight and body condition are controlled by adjusting feed quantity so that a slow constant increase in weight (30g/week) is achieved as the male grows older. The revised weight profile in lay for UK Flocks is shown below. (See Table 1)






Sample males should be weighed frequently to ensure that this is achieved. Each sample male should be evaluated to determine if it is maintaining the ideal body condition in order to breed. Changes in flock feed quantities will be made based on the sample evaluated. A sample size that is too small can mislead the manager.

After 30 weeks of age, male weekly body weight gain should be approximately 30 grams when averaged over a three week period. Body weight data should be used with other husbandry information to make feed allowance decisions. The amount of feed the males can vary greatly depending on the ability of the feeding system to keep males and females from eating each others feed. With excellent control, male feed allowance is normally in the range of 130-160 grams per male/day and should be always increasing through the male's life. As a rough guide, an increase of 1g per week, from 30 weeks of age, should maintain growth and condition. Feed amounts needed depend on the security of the separate feeding systems and the energy level of the feed.

Both underfeeding and overfeeding of males are possible, and can cause problems. Underfeeding is more common after 40 weeks of age. Males require food for maintenance, growth and condition and to maintain mating activity. If nutrition is marginal, the first thing to go will be mating activity.

The males will begin to appear dull and listless, showing excess feather loss, reduced fleshing, reduced mating activity and reduced less crowing. In addition, vent colour will become paler and the variability of vent colour between males will widen. When this occurs, the more active males will work for a short period, using their body reserves, but other males will cease to function. If the condition reaches the final stages, a significant number of birds will not recover. Overall, this will result in reduced fertility.

Vent Colour

Red = Working well     
Pale = Performance falling off,
less mating



On observing any of these symptoms, a number of corrective steps must be taken:

Check the male feeder is not available to females.
Check that male feed space is constant (18 cm or 7-9 males per pan)
Feed allowance should be increased 5-10 g /day).
The accuracy of weekly average weight gain data should be checked and a sample of the birds reweighed if in doubt.
Overfeeding of males will lead to males that have excessive breast development and excessive weight which can lead to damage to females, more stress on the male's joints and foot pads.

Routinely cull individual males according to their physical condition.

Males with poor feet, poor legs, poor fleshing, poor comb and vent colour should be culled as seen on a daily basis. As males are removed feed space must be adjusted to remain constant.

The technique of managing male breeders is not 'rocket science'. Attention to detail, monitoring and maintaining the correct weight gain and profile will reduce the possibilities of reduced fertility levels. Observing behaviour and reacting to it will help in maintaining a flock of quality males which will maximise fertility to the end of lay.

The profile discussed here is based on UK results and is intended for producers in the UK. Outside the UK discuss the subject with your local Aviagen Technical Manager with a view to tailoring the profile for local environmental conditions, nutritional inputs and management practices.

Source: Aviagen, Courtesy of Poultry World, October 2005

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Making Every Egg Count
By Dave Watts, UK Regional Accounts Manager, Aviagen - Genetic improvement over the last few decades has seen major improvements in breeder egg production and chick output, but are you getting as much of this from the bird as you could? Two areas where output can often be gained are in better control of eggs laid on the floor and in effective management of late egg size. This article looks at management advice for these areas to maximise hatching egg output from the flock.

 
Controlling Floor Eggs
With improved rearing management giving better control of uniformity and body weights in rear, combined with improvements in genetics, Ross 308 breeder flocks now come into production very quickly and regularly peak at 85 - 88% by 28/29 weeks of age. These high peaks can put a great deal of pressure on the available nest box space and unless steps are taken to minimise the opportunity for birds to lay their eggs on the floor, they will start to and continue to do so through the life of the flock.

It is good practice to install perches during the rearing period to train and stimulate females in their nesting behaviour. Sufficient numbers of perches to provide 3cm/bird, or sufficient for 20% of the birds to roost, should be placed in the females’ rearing pens at around 4 to 6 weeks of age.

When the birds are transferred to the laying house, they should be placed onto the slatted, rather than onto the litter area and very soon after transfer the egg collection belts should be run at least once a day. This will allow the birds to get used to the noise. If the belts are not run before the start of production, the noise will frighten the birds from the nests and onto the litter area where they will then lay their eggs.

Auto nests require a sloping, slatted area extending to approximately 40 to 50 inches (100-125cm) from the front of the nest and which should be 16 to 18 inches (40-45cm) above litter height. Avoid putting any feeders on the slats as these will act as a barrier to birds getting to the nests as they come into lay.

Begin to open the boxes for one or two hours a day from 19 to 20 weeks of age as by this age the birds are looking for somewhere to lay. If left any later – until first egg, for example - many birds will already have been put off using the nests and the damage will have been done.

Light intensity must be a minimum of 60lux during the laying period; when increasing light intensity at the start of lay, increase that above the nest system first, as this will encourage activity around the nests. In rear and move systems, avoid excessive litter depth at first, as deep floor litter can offer a very attractive alternative to the nest.

Finally, when not in use, always seal off the front of the egg collector belt in the egg collection area, as this can act like a wind tunnel, causing drafts. Quite often birds will not use the first few boxes as they will feel cold. This is usually why floor eggs are found around the front end of the shed. A piece of wood, polystyrene or sponge is adequate to block the end, not thin, hanging plastic strips as these are ineffective.

It is important to manage the introduction of the males to the females well and to manage mating ratios during the early period of lay. Mating behaviour should be closely monitored to ensure that over mating or overly aggressive male behaviour is not forcing females to hide in corners or under feeders on the floor area to lay their eggs.

Set feeding times to avoid the peak of egg laying activity. Feeding times should be either within 30 minutes of lights on or 5 to 6 hours after lights on to prevent the majority of hens coming off the nest to feed. It is also good practice at the onset of production, to walk around the house 10 to 15 times per day, encouraging females out of corners and up into the nests. A bit of extra work when the flock is coming into lay will pay dividends later.

Management of Late Egg Size
Once the flock comes into lay and the birds have been trained and encouraged to lay their eggs in the nests, then a second opportunity to maximise hatching egg yield comes from effective management of the interaction of egg production, bodyweight and egg weight.

As the flock ages, the hens gain bodyweight while the rate of lay gets less; this is accompanied by an increase in egg size. Excessive egg size during late production will make egg handling more difficult and egg shell and albumen quality tend to be worse, at the extreme leading to poorer chick quality.

Close control of female bodyweight will help maintain good persistency of lay. Generally, a higher producing flock will produce eggs of a lower weight than one where persistency is poor. Good bodyweight control is therefore a vital part of managing egg size.

Trials have shown that if birds are allowed to become overweight, in this case 12% above target, then late egg size will be approximately 1.5g heavier than that of flocks held to the Ross target weight throughout.

Nutritional changes are sometimes made in an effort to manage egg size directly, but the benefits are usually limited. Any changes to the ration should be made with care so as to ensure there is no negative effect on egg production. Lower levels of linoleic acid, protein or specific amino acids such as methionine, after 40 to 45 weeks of age can help.

Under performing flocks are often offered increased feed levels to try to stimulate better performance. If an improvement is not achieved then the extra feed must be withdrawn immediately. In a poorly- performing flock, if peak feed levels are left too high, the pullets are likely to gain excessive bodyweight, egg production will drop further and late egg weight will increase. The situation will be made worse if feed is then withdrawn very aggressively after 35 weeks, as the heavier pullets will by then have a higher requirement for energy to support body maintenance, and in this situation, rates of lay can drop very fast.

The modern broiler breeder is continually changing, due to continuous genetic improvement and our management of the bird must therefore also change. The key to maximising hatching egg output is in responding to the needs of the bird and ensuring that they are trained in roosting and nesting behaviour from an early age. They should have free and easy access to adequate nest space and should be provided with the right nutrition at the right time to balance the needs of maintaining growth and producing eggs.

As always, the answer lies in attention to detail, especially in the early stages, if the benefits are to be maximised.

Source: Aviagen and Courtesy of Poultry World, April 2005

[mikey]

Golden Rules For the management of Hybro females
By Hybro B.V., Boxmeer, The Netherlands - This article by Hybro B.V. explains the golden rules for the management of Hybro females.

 

Check your housing and equipment!
Overstocking and competition result in stress on the birds. Avoid high stocking density, both in rearing and production (see management guide for recommendations.) Allow at least 15cm feeder space per bird, and one bell drinker per 65 birds. Make sure the feed is distributed within 4-5 minutes. Have your heating and ventilation in good order. Dark-out rearing is highly recommended: rearing houses should be completely light-tight, even at full ventilation.

Give them a good start!
Pay attention to the details: well organised housing, evenly spread litter (not too deep!), sufficient brooder temperature and adequate pre-heating, clean fresh water and feed, adequate lighting and so on.

Make the grade for 5 week body weight!
Start feed restriction early enough to ensure controlled growth from the beginning – as soon as ad lib feed exceeds 35g/day.

Make an early start on uniformity!
Start grading as early as possible, but not later than 4 weeks of age. Grade several times during rearing. Place the birds in groups and feed them to achieve highest possible uniformity at 10-11 weeks. After 12-14 weeks, focus on keeping bodyweight parallel to the standard rather than bringing them back to it.

Use grower feed with low nutrient concentration!
During rearing, use feed with an energy content of 2600-2650 kcal/kg, as it allows more feed increments, resulting in better uniformity and less stress.

Increase the feed every week!
Refer to the growth rates of the previous 2 weeks to determine weekly feed increments. These should increase smoothly and gradually, avoiding big jumps.

Don’t correct growth curve after 14-15 weeks!
If bodyweight deviates from the standard at this age, aim to keep the curve parallel to the standard. In this period, focus on an accurate weekly growth rate rather than a 20-week bodyweight target. A reduction in growth rate will result in an underdeveloped bird.

Start light stimulation according to the body weight!
Don’t start light stimulation before the average body weight of the flock is 2200g (dark-out rearing) or 2350g (daylight rearing). If uniformity is poor, delay the lighting for a further week. Make the first increase big enough (2 hours in blackout rearing, 3 hours in daylight or brown-out rearing) and increase the light intensity at the same time. Try to be on 14-15 hours of light at 5% production. Increase the day length again at 60% production, to stimulate the later maturing birds.

Keep control over the point of lay!
Avoid over-fleshing by limiting the use of a rich pre-lay feed to 2-3 weeks prior to the start of production. Decide on the use of pre-lay feed at around 20 weeks, and only use it when the bodyweight, fleshing or feathering of the birds is below standard. After 20 weeks, focus on growth rate rather than bodyweight. Avoid over-feeding before onset of lay. The objective is to be at approximately 115- 125g feed at 5% production. Be aware that the males usually steal from the female feeders up to 26-28 weeks of age.

Once production starts, gradually build up the rate of feed Increase!
Between 5% and 35% of lay, give an extra 0.5-0.7g feed for each 1% increase in production. After 35% production, give 1g feed for each 1% increase. Adjust the feed amount every 3-4 days. Don’t give peak feed before 60-65% daily production, and avoid over-feeding at peak, as it will quickly result in overweight. 165-170g of peak feed should be sufficient.

Control growth from peak of lay to end production!
Start reducing the feed quickly when peak production is reached. Reduce by 2- 3g per bird per week in the first 3 weeks, starting from the first week of peak production. Start to reduce even if the flock under-performs. Continue to reduce the ration slowly and gradually, to keep weekly growth at 10-15g. Limit feed reductions after 45-50 weeks of age.

Source: Hybro B.V. - Taken from website September 2005

[mikey]

The Impact of Genetics on Breeder Management
By Ron Meijerhof, senior technical specialist, Hybro B.V., Boxmeer, The Netherlands - In the world of broiler meat production, rapid developments are being made. The increase in broiler performance for all commercial breeds has been tremendous over recent years, measured not only by improvements in growth per day, but also in terms of feed conversion, carcass yield, breast meat yield, mortality and leg quality, for example.

 
Trends in breeder performance are not so clearly pronounced and regular, however. Today we find that modern breeders can produce peaks of up to 85 per cent, which is certainly more than we could achieve seven or eight years ago. On the other hand, it has become more difficult to obtain these maximum performances, because the birds require much stricter control without room for errors. This is particularly evident in the management of modern males. The reason for this is simple.

Important improvements
When we look at the cost price of a kg live broiler, even without processing, the cost of producing a day old chick is only about 15 per cent of the total cost price, with 85 per cent the cost of growing that day old chick into a broiler. If we calculate the cost price of a kg of meat, including the processing costs, the cost of the day old chick is less than 10 per cent of the total cost price.

This means that the cost of rearing breeders, including feeding, housing, incubation and chick processing, only adds up to 10-15 per cent of the total cost, and therefore that an improvement in breeder performance has a relatively small influence on the total cost price of the bird.

For this reason, improvements in broiler performance are typically much more important than improvements in breeder performance, which in any case are only acceptable if they have zero or negligible effect on the broiler traits. This is why in the long term most breeder companies try to keep breeder performance equal or constant to slightly positive, instead of delivering enormous improvements in breeder productivity that will consequently have a negative impact on broiler performance.

Although all breeding companies are aware of this - and effective in achieving further improvements in performance - not all companies regard the key points for improvement in the same way. Between companies and breeds, we see differences in performance, based on the importance that the individual companies give to certain aspects of broiler production.

Breeding is a long term business. It takes at least four or five years to see a change in pure lines being reflected in product performance in the field. Therefore it is vitally important to assess the direction in which markets will develop in the future accurately – and to anticipate this early enough within the breeding programme to take full advantage of market trends when they occur.

Multiple crosses
Broilers are the final product of crossing several lines. Consequently at breeder level, the genetic background of males and females can be (and almost always will be) completely different. This means that to some extent it is possible to realise broiler trends in the parent line of choice. For example, growth in a broiler can be realised by crossing a very fast growing male line with a normally growing female line, or vice versa. The selection of lines and their specific characteristics has an enormous impact on the reproduction traits, and on the management strategies that have to be applied to a certain breed.

Let’s assume that broiler growth is obtained by crossing an extreme growing, genetically heavy male with a slow growing, genetically light female. As a result, it can be expected that this breed will easily produce eggs but fertility, especially at a later age in the flock, will be more difficult to obtain. When the reverse option is used, so a heavy female with a light male, fertility will be relatively easy to achieve but getting the optimum number of eggs will be more challenging. Given these scenarios, it is clear that the management strategies and practices for these two resulting breeds will be different.

Selection goals and their influence on breeders
The breeding programme for each individual line in a breeding company is defined by breeding goals. In other words, for every line, a selection programme must be defined that describes on which selection parameters the focus must lie for that specific line. Of course breeding companies do not only select for growth, but also for other broiler traits such as yield, meat quality, feed conversion and mortality, as well as on breeder traits like egg production, shell quality and hatchability, for example. The challenge with selection is that it not only changes the parameters that the birds are selected on, but also parameters that at first sight appear to have little to do with the breeding goals.

A good, example of this is in the relationship between growth and reproduction. It is well known that a strong selection on growth has a negative influence on reproductive performance. This means that relatively more pressure has to be put on selection for reproduction if at the same time more pressure is given to selection for growth, in order to maintain constant or even slightly increased reproduction.

However, selection on yield and feed conversion also has an influence on reproduction. If high yielding, feed-efficient birds are stimulated too early and too much with feed without being able to produce the expected eggs, the birds will process that extra feed in their own body and grow excessive meat very rapidly. This meat influences the production of sexual hormones in the birds, and as a result the birds become over-stimulated. This results in poor production and high mortality, because the birds cannot handle the high stimulation of the reproductive tract.

If we take reproduction and growth as an example, we can question what causes the often discussed negative correlation between these two traits. There are two main reasons, either related to the individual hen or to the performance of the flock.

Individual birds
Egg production by an individual hen is maximal if a follicle (yolk) is produced every 24 hours, turned into a first grade quality egg and laid. This egg per day equates to 100 per cent production. When we do select on growth, it becomes more difficult for a bird to produce each follicle in good time. Often it will take the hen longer than 24 hours, and often a pause day (day without an egg) will be introduced. This is because the hormonal or developmental sequences in the bird will not be as optimal as they should be. It is not so much that the optimal sequence can no longer be achieved, but that the circumstances to get the birds into that condition are becoming much more critical. The same holds for the consistency of that bird: how long can it maintain that high level of follicle production without causing more pause days.

Flocks of birds
Of course a flock of birds is a mix of thousands of individuals, each with their own individual capacity to lay eggs, but also with their own demands on the environment to get into that optimal stage of development for producing an egg every 24 hours.

Due to selection on broiler traits, establishing the correct stage of development and the fine tuning to get to that stage is increasingly critical. The bird is becoming less forgiving in non-optimal situations, and therefore less deviation from that optimal stage is acceptable to obtain good results. As large flocks of birds will show a natural variation in development, the risk of non-optimal treatment for groups of birds increases. Every bird in the group is still able to produce, but as we manage the flock based on the average demand of all the birds, an increasing number of the birds will suffer from non-optimal conditions. Factors that increase that natural variation in development (poor rearing, high stress, poor equipment, high disease pressure etc.) will make it even more difficult to obtain good results.

Consequences for management
Selection for fast growing, high yielding broilers influences the reproductive capacity of the parent stock. To obtain good results in reproduction, we have to focus on delivering adequate management to address the needs of this specific type of bird.

Start of the flock
As individual birds accept less and less deviation from the optimal, it is crucial to have a very uniform flock at the onset of lay, to get as many birds as possible to that point simultaneously. This is more than just uniformity in bodyweight at a certain age, as it also includes uniformity in development. Achieving maximum uniformity is also about more than grading. It starts with good chick quality and start up of chick development, uniformity in frame size and the avoidance of stress and diseases, among other factors. The start up period is especially important.

High-yielding broilers (and therefore their parents) are normally selected to have a high development of organs before the real growth starts, to be able to support the rapid growth of protein later in life. This increased development in the first days normally means that the birds tend to start rather slowly and are more sensitive, especially to temperature. It is therefore very important to ensure that the house is sufficiently preheated before the birds arrive, to prevent them from becoming cold. If the birds become cold shortly after arrival, some of them will not find the feed and water for several days, and uniformity will already be adversely affected after just one week.

Quality of rearing
Even more than with classical breeds, the rearing period of high-yield breeders is crucial for obtaining maximum reproduction results. Focusing on the quality of rearing, uniformity of the flock and adequate development at the start of production pays off very rapidly. The key word in rearing is ‘gradual’. It is important to avoid changing the feed amounts too rapidly, but rather try to gradually increase the feed week by week. In the first 6-7 weeks of rearing, the weekly increase is 2 to 3 grams, then it changes to 3-4 grams until 15-16 weeks of age. In the final weeks of the rearing period, the increases will be 4 to 5 grams each week. It is very important that these weekly increases are steady and constant, to avoid any sudden changes. That sometimes means that even if the flock is a bit over- or under -weight, we should not try to correct it too quickly, but rather try to anticipate development for the coming weeks.

Start of production
A crucial period in the development of high-yielding breeders is the onset of lay. Genetically, these birds are capable of producing high amounts of (breast) meat. Managing the amount of meat growth is very important for obtaining good results. A minimum amount of fleshing is needed, to get the birds ready for egg production. However, over-stimulating with feed in this period to push the birds into egg production has a very negative impact, as the birds will grow meat very rapidly. This rapid meat growth will over-stimulate the sexual hormones and the reproductive system, resulting in poor production and high mortality. This means that the amount of fleshing must be limited by restricting feed stimulation. In this respect, high-yielding breeds in particular differ from more traditional breeds, as they are not able to handle such high feed stimulation.

The best tool for controlling this is to check the formation of the breast muscle on a regular basis. The aim is to have a U shaped breast for optimal production. If a bird is underdeveloped, the breast will feel like a V, which means that there is not a lot of meat around the keel bone. If we over-stimulate the birds either in feed quantity or in protein, we see that the breast muscle quickly develops in a W shape, which indicates over-fleshing. This over-fleshing will result in reduced production, more double yolks and increased mortality. When the birds are well developed, it is important not to over-stimulate them with a high amount of protein. To prevent this, increase the feed amount in a steady line from end of rearing to start of production, aiming at approximately 120 grams of feed at 5 per cent, regardless of the age of the flock.

Peak feed
Genetic selection for growth also influences the choice of management during the peak production phase. A strong selection on growth will mean the birds grow very fast if feed intake is not well-controlled. This means that for fast growing breeds, the amount of feed has to be reduced after peak more rapidly and aggressively, to control growth and maintain persistency and hatchability. Start feed reduction as soon after peak as possible, or the birds will gain weight on the excessive feed that is given - and then require extra feed to maintain that extra body weight.

It is good practice to reduce feed amounts one week after peak production is reached. Reduce the feed for three weeks by approximately 2 to 4 grams a week, divided into two feed reductions per week. After each feed reduction, monitor egg weight, body weight and production. While both egg weight and body weight should continue to increase, production should not decrease by more than one per cent each week. Only if that is achieved, introduce the next feed reduction.

After these three weeks of feed reduction, continue to reduce the feed by one gram per week until about 45-50 weeks. From this point onwards, it is often advisable to maintain constant feed. The aim of this whole feed reduction process is to keep increasing the bodyweight after peak at a level of about 10g per week. This is not because the birds need to grow 10 grams a week, but if the flock grows on average 10 grams, the poorest birds will at least not lose weight.

Conclusions
Changing the characteristics of birds by genetic selection has an influence on the capacity of the birds to reproduce. Not only selection on growth, but also on meat yield and feed conversion has, among others, a negative impact on reproduction. This can be partly recovered by putting more selection pressure on reproductive performance, and partly by adjusting the management programme to the specific birds. Applying classical flock management conditions to fast growing, high yielding breeds will not automatically give the highest production results. Continuous adjustment and fine-tuning of the management programme to deal with the continuous genetic changes in the birds is necessary.

Source: Hybro B.V. - May 2005

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Defining Chick Quality
By Brian D. Fairchild, Extension Poultry Scientist, CES, University of Georgia - Chick quality is still a term than many breeder, hatchery and broiler people still have a hard time defining. Most everyone can identify poor quality chicks from good quality chicks. However, when three people are asked to define chick quality, three different descriptions would be received.


Currently chick quality is mainly based on observations such as whether or not the chick is alert, dry or wet, whether the navel is completed sealed, and deformities. While these are a good start, there are chicks than can be dry, have completely sealed navels, no deformities but still do not perform well. Researchers will continue to search for an objective measurement (one that will not vary from person to person) but in the mean time the best measurement is to use a combination of observations. Most people working to evaluate chick quality agree that first week mortality may be the best measure available. However, the information if after the fact and growers and broiler flock supervisors need the information as soon as possible to make management decisions need to optimize that flock’s performance.

There are several factors that can affect chick quality. These are listed in Table 1. Since there is no objective way to measure chick quality at this time, it is important to define how chick quality is determined. One group in Belgium has been evaluated chick quality from three different broiler breeder lines. In order to report and compare chick quality they have come up with a system that has been successful in their observations. It should be noted that there is still a possibility that the information will differ from person to person, but this appears to be a good start. Table 2 describes the parameters they used for determining chick quality and Table 3 demonstrates the scoring system. The score level for each parameter was determined based on the importance to chick survival and the severity of any anomaly it may carry.





 



While this system was useful to this project, some alterations could be made to fit a companies needs. The important thing to remember is consistency when evaluating each parameter. Other methods for determining chick quality have been developed and tried and are quite similar to the one described above. The common feature is that each method used multiple parameters to assess chick quality.
References
Tona, K. F., Bamelis, B. De ketelaere, V. Bruggeman, V. M. B. Moraes, J. buyse, O. Onagbesan, and E. Decuypere, 2003. Effects of egg storage time on spread of hatch, chick quality, and chick juvenile growth. Poultry Sci 82:736-741.
Tona, K., O. Onagbesan, Y. Jego, B. Kamers, E. Decuypere, and V. Bruggeman 2004. Comparison of embryo physiological parameters during incubation, chick quality, and growth performance of three lines of broiler breeders differing in genetic composition and growth rate. Poultry Sci 83:507-513.

Source: University of Georgia - Poultry Science - May 2005

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Breeder Nutrition and Chick Quality
By Marcus Kenny and Carolyne Kemp, Aviagen - This article by Aviagen discusses how the nutrition of the breeder hen affects the chicks physiology at hatching.

 
The developing embryo and the hatched chick are completely dependent for their growth and development on nutrients deposited in the egg. Consequently the physiological status of the chick at hatching is greatly influenced by the nutrition of the breeder hen which will influence chick size, vigour and the immune status of the chick.

Table 1. The necessary change in hatchery or broiler performance to equalise profitability when breeder feed cost is changed by 1% per tonne (for example from £UK 140.00/tonne to £UK141.40/tonne or £UK138.60/tonne).
Hatch of total eggs (%) 0.24
42 day liveweight (g) 7.4
42 day FCR 0.0015
42 day mortality (%) 0.07-0.45*
*depending on age of mortality. Calculated using input-output values for UK industry 2003 (Kemp and Kenny 2003). 


The financial effects
Nutritional decisions for breeders need to take account of the overall economics of the whole production cycle. Table 1 shows the changes in hatchery and broiler performance that are required to equalise the effect of a 1% increase in breeder feed cost on the profitability of the whole production cycle. Only one of these changes is required to have the necessary economic effect; in practice all are likely to move positively making the measurements of any one change difficult.

The calculations are done under typical UK 2003 conditions and they show quite clearly that small improvements in bird performance are required to ‘pay’ for more expensive breeder feed. Conversely, apparent savings in breeder feed cost can readily lead to an overall loss if small changes in broiler performances are ignored.

Similar economic analyses have been conducted by Mississippi State University which, based on US integration 2002 costs, demonstrates that a measurable improvement in progeny liveability as a result of hen diet change can be profitable. The key point is that trying to cut the cost of a breeder feed may easily reduce the profitability of the overall enterprise.

Influence of feed allocation
Underfeeding the hen can have an impact on chick quality and this is particularly noticeable in the early production period. Modern hybrid parent flocks commence production at a faster rate than in the past and consequently egg output increases over a shorter time span during the early laying period. Feed allocations during this period have not necessarily increased in line with this egg production trend. Low feed allocation intake by young commercial breeder flocks has been shown to compromise nutrient transfer to the egg, resulting in increased late embryonic death, poorer chick viability and uniformity.

In a recent study by Leeson (2004) broiler breeders were fed different levels of feed through peak production varying from 140 to 175 grams. Although the increased feed allocation increased bodyweight there was no influence on egg size, however chick weight was influenced by feed allocation (Table 2). Of equal importance is the effect of overfeeding on ovarian development. In experimental studies ad libitum feeding has been the most widely used model for overfeeding which can result in excessive follicular development or Erratic Oviposition and Defective Egg Syndrome (EODES).

Flocks with EODES generally have poor shell quality, a reduced duration of fertility and poor hatchability. It is also known that fewer sperm will survive but it is not clear how the surviving sperm are affected and if they generate a weaker embryo. The same authors also warn that the effect of aggressive feeding two to four weeks after photostimulation reduces productive performance throughout the life of the flock.

In this period the bird switches from primarily growth to a reproductive state. The young birds’ reproductive hormone system is not mature enough to deal with high nutrient intakes; nutrients are instead metabolised to egg yolk lipid which contributes to excess follicle development.

Research shows that nutrient supply to the broiler breeder is of consequence to chick quality and production performance. This places greater emphasis on the nutritionist providing the correct nutrient density diet and the flock manager to provide appropriate feed intake to the bird coming into lay.

Table 2. The effects of breeder feed levels on chick weight.
Peak breeder feed (g/b/d)  30 week breeder chick weight (g)
140 40.3
147 40.0
155 41.5
162 41.7
169 41.8
175 42.0


Diluted breeder diets
The use of diluted breeder diets is receiving a lot of attention in Western Europe on the basis of improvements in bird welfare. Experimental work feeding low energy density diets to young parent stock gave a delayed onset of oviduct development, increased early egg size, faster development of the embryo and a higher live weight of day old chicks. When broiler mortality was above average, low density broiler breeder feeds gave a significant reduction in mortality of offspring. Other experimental work showed improvements in breeder productive performance when diluted diets were fed in the rearing period.

Vitamins
Vitamins are involved in most metabolic processes and are an integral part of foetal development, therefore the consequence of suboptimal levels of these nutrients in commercial diets are known to result in negative responses to both parent and offspring performance. Vitamins account for about 4% of the cost of a breeder feed, so economising on vitamin inclusion rates is rarely an option

Table 3. Some practical recommendations for vitamin
supplementation of breeder feeds (Fisher and Kemp 2001).
Vitamin Leeson & Summers (1997) DSM Ross
A (iu/g) 7 10-14 13
D3 (iu/g) 3 2.5-3.0 3
E (mg/kg) 25 40-80 100
K (mg/kg) 3 2-4 5
Thiamine (mg/kg) 2.2 2-3 3
Riboflavin (mg/kg) 10 8-12 12
Pyridoxine (mg/kg) 2.5 4-6 6
B12 (mg/kg) 0.013 0.02-0.04 0.03
Nicotinic acid (mg/kg) 40 30-60 50
D-pantothenic acid (mg/kg) 14 12-15 12
Biotin (mg/kg) 0.2 0.2-0.4 0.3
Folic acid (mg/kg) 1 1.5-2.5 2



The levels of vitamin supplementation recommended by different sources have been summarised in Table 3. Generally there is a shortage of information on vitamin requirements of broiler breeders especially when related to offspring performance. Most of the breeder work is quite dated and since that time breeder performance has changed. It would be impossible to review all the literature in this article, however a review of work on fat soluble vitamins, biotin and pantothenic acid have shown that vitamin E has the largest impact on progeny.

Table 4. Impact of dietary breeder vitamin status on bodyweight, enzyme activities, tissue characteristics and immunity of progeny.
Vitamin Progeny response
Vitamin A Increased liver vitamin A in embryonic and chick liver but decreased vitamin E, carotenoids and ascorbic acid. Surai et al. (1998).
Carotenoids No positive impact on chick growth, organ development or humoral immunity in chicks five weeks post hatching. Haq et al. (1995).
Carotenoids Transferred from the hen to the yolk but not absorbed well by the embryo and subsequent chick. Haq and Bailey (1996).
Carotenoids and Vitamin E Carotene, vitamin E, and their combination improved and vitamin E lymphocyte proliferation, but only vitamin E improved humoral immunity. Haq et al. (1996).
Vitamin E Vitamin E levels of 150 and 450mg/kg increased passively transferred antibody levels in chicks to Brucella abortus up to seven days of age. Jackson et al. (1978).
Vitamin E Increased vitamin E in chicks’ yolk sac membrane, liver, brain and lung all of which had reduced susceptibility to peroxidation. Surai et al. (1999).
Vitamin E Increased progeny antibody titers to sheep red blood cells at hatch. Boa-Amponsem et al. (2001).
Vitamin E and Selenium Increased liver glutathione activity in chicks. Increasing selenium increased selenium dependant glutathione peroxidase in chick liver. Surai (2000).
Vitamin D Tibial calcium was increased at two weeks post hatching and tibial ash increased at four weeks of age by increased vitamin D3. Ameenudin et al. (1986).
Vitamin K Chicks from hens fed vitamin K deficient diet had reduced tibial glutamic acid levels at day one and 28 post hatching but tibial glutamic acid was restored by supplementing the chick diet with vitamin K. Lavelle et al. (1994).
Biotin Foot pad dermatitis and incidence of breast blisters were decreased in some trials in chicks from hens fed biotin fortified diet. Harms et al. (1976).
Biotin As biotin increased in the hens’ diet, yolk and chick plasma also increased. Biotin concentration in chick plasma was poorest from young hens. Whitehead (1984).
Pantothenic acid Liveability of chicks was best when hens were fed 20mg/kg diet of pantothenic acid. Utno and Klieste (1971).
Adapted from M. Kidd 2002 



The production and economic effects of vitamin E supplementation are best shown by Hossain et al (1998) where a basal corn soya feed was supplemented with 25, 50, 75 and 100mg/kg vitamin E. The effects on hatchability were not significant; however the best hatchability was obtained at 50mg/kg at 52 weeks. Offspring immune response continued to increase up to 100mg/kg. In the same studies higher final bodyweights at 42 days, improved FCR and reduced mortality were observed in chicks from eggs which had been injected with vitamin E in ovo.

Haq et al., (1996) working with very high levels of vitamin E (134mg/kg versus 412mg/kg) found no growth response to 21 days and an improvement in FCR for the offspring of hens receiving the supplemental feed. In other studies the combination of selenium and vitamin E to broiler breeders has been shown to increase liver glutathione activity of progeny. In general it seems to be justified to supplement practical breeder feeds with 100mg/kg vitamin E.

There appear to be mixed reports on the efficacy of vitamin C; some experiments suggest a positive response, but a more recent study failed to detect any benefit on any production parameter. This lengthy study used corn soya diets supplemented with 75mg/kg stabilised vitamin C which when analysed recovered 49mg/kg which might explain the variability of response.

The influence of increased vitamin levels fed to young parent stock on progeny performance is an area which has received significant commercial interest. Work conducted at Aviagen Ltd has shown chicks derived from 31 week old parent stock fed elevated levels of vitamins showed improved growth to 11 days and reduced mortality compared to chicks derived from 42 and 45 week old parents. Similar responses have been found in the field where chicks derived from young parents fed increased levels of vitamins have benefited in terms of viability and liveability. Perhaps this supports the need for further work exploring the vitamin requirements of the breeder in the early production period.

Whitehead (1991) proposes that a basis for making recommendations is to feed vitamin levels that maximise the resulting level in the egg. For vitamins with active transport mechanisms (thiamine, riboflavin, biotin, cobalamin, retinol and cholecalciferol) these levels reflect the saturation of binding proteins.

Levels derived in this way include 10mg/kg for riboflavin and 250 microgram/ kg for biotin. Whitehead (1991) contrasts this level of riboflavin with the conventional requirement (4mg/kg in this case) but the higher figure – the upper limit to nutritionally useful range – may be a better guide to good commercial practice.

Table 5. Blood cell count of the broiler derived from parents fed high or low vitamin and mineral levels (Rebel et al 2004).
  Breeder low vitamins/minerals Breeder high vitamins/minerals
Heterophil 5.3 3.8
Lymphocyte  4.6a 21.4b
Monocyte  1.1 5.3
Basophil 0.0a  5.4b


Table 6. Summary of minerals fed to breeders shown to have an effect on progeny performance. 
  Growth Liveability Immune function Skeletal
Fluoride       X
Phosphorus       X
Selenium   X     
Selenomethionine X   X   
Zinc X   X X
Zinc and methionine   X     
Adapted from M. Kidd 2002 


Vitamins and chick immunity
Reference has already been made to the effect of vitamin E on chick health and immune function, while other vitamins have been researched none show the same degree of effect as vitamin E. Table 4 summarises work investigating the effect of different vitamins fed to breeders and consequent impact on progeny health. Recent work by Rebel et al (2004) investigated the effects of several elevated levels of vitamins and trace elements fed to breeders and broilers on the immune system of birds infected with malabsorption syndrome.

Broilers derived from breeders fed elevated vitamins and mineral levels had increased numbers of leukocytes at day old which indicated stimulation of the immune system (see Table 5).

Fig. 1. The effect of protein-to-energy ratio in the breeder feed on chick weight at hatch (Spratt and Leeson 1987).


Major minerals
Calcium, phosphorus, sodium, potassium, magnesium and chloride are involved in shell formation hence general improvements in shell quality lead to better egg and chick quality. Variations in maternal phosphorus supply have been shown to influence bone ash of young but not older progeny. Broiler performance was not affected by these treatments so the practical significance of this work is not clear but the use of relatively low phosphorus levels in breeder diets, while benefiting egg shell quality, may not lead to the best possible bone integrity in the early stages of growth.

Trace minerals
Most interest in this field has centred on the use of chelated minerals which have been shown to increase deposition in the egg and transfer to the tissues of the hen and the embryo. Most recent work has focused on the antioxidant status of breeders, embryos, offspring and the role of selenium. Surai (2000) has shown the role of Selenomethionine on both vitamin E and glutathione peroxidase levels in eggs, embryos and chicks up to 10 days of age.

The economic benefits of using Selenomethionine compared with sodium selenite have been examined in a number of unpublished field trials in the UK. Hatchability improvements ranged between 0.5-2.0 chicks per 100 eggs and in another trial 0.3-0.7 chicks per 100 fertile eggs. Few of these tests involve a proper assessment of subsequent broiler performance although comments about chick quality are generally positive.

In one of the commercial trials mentioned an improvement of 0.5% in mortality and cull rate at 10 days was observed when organic selenium replaced sodium selenite. Research has indicated that the improvements in chick immunity as a result of mineral fortification of hen diets may result in improved liveability. Flinchum et al. (1989) demonstrated that leghorn breeders fed supplemental zinc methionine to a zinc adequate diet had progeny with improved survival to an E. coli challenge. Similar improvements to progeny liveability were seen with breeders fed supplemental zinc and manganese amino acid complexes. Table 6 is a summary of those minerals which, when fed to breeders, have an effect on progeny performance.

Nutrient levels in the breeder diet
There is clear evidence that a high protein to energy ratio depresses hatchability, and probably chick performance. The experiment by Whitehead et al. (1985) shows the effect of excess protein where the higher protein level reduced reproductive performance, producing 3.1 fewer chicks per 100 fertile eggs.

Chick quality was also reduced so that the difference in saleable chicks was 4.0 per 100 fertile eggs. The effect of energy protein ratio in the breeder feed is shown in Fig. 1. This emphasises both the effects of excess and inadequate protein, and also indicates that the optimum level is quite steeply defined.

According to this trial the optimum protein level is at 5.52g protein per 100kcal which converts to an optimum of 15.18% protein for a diet containing 2,750cal/kg of feed. The protein level of the diet and its ratio to energy is important not only for parent performance but also for chick quality.

Table 7. Commercial comparison of breeder feeds based on wheat or maize (400g/kg).
  Advantage of maize over wheat based feed
Mortality during lay (%) -1.7
Total eggs (per hen housed) +3.8
Hatching eggs (per hen housed) +4.8
Hatching/total eggs (%) +0.9
Hatch of set eggs (%) +0.6
Hatch of fertile eggs (%) +1.1
Second quality chicks -0.1
Based on a comparison of two commercial houses each containing 6500 female grandparent breeders. Data to 58 weeks (Ross Breeders, unpublished data, 1998). 


The effect of feed ingredients
There is evidence of improved breeder performance when maize is compared to wheat as the main cereal in breeder feeds. From a survey of many depleted commercial flocks overall hatch of fertile eggs in the UK based on wheat diets and Brazil based on maize diets is 83.3 and 86.2 per 100 eggs respectively. Other management factors may contribute to this difference in hatchability other than cereal source; male management is very good in Brazil and the resulting high fertility may also contribute something to this difference. Unpublished commercial development trials from the Netherlands and Aviagen Ltd grandparent flocks (see Table 7) support this observation.

The most likely benefit of maize is probably in shell quality and thickness. From the same data average poorer shells with specific gravity of <1.08 accounted for 26.1% of eggs from wheat fed hens and 17.1% from maize fed. Studies of hatching losses showed less late dead embryos (>18 days) and less bacterial contamination. These two responses are expected with eggs of better shell quality.    Evidence about fat levels and sources is conflicting but there is no question that this is an important consideration. Added fat levels should be kept low in breeder feed (1-3%) and preference given to unsaturated vegetable oils rather than saturated animal fats. Work from Mississippi State University compared maize oil and poultry fat and generally supported the use of more unsaturated fat (see Table .

Maize oil increased 21 day bodyweight over that of poultry fat and improved slaughter weight of broilers in comparison to equal levels of poultry fat and lard.

Table 8. Experiments comparing fat sources and/or levels for broiler breeders.
Reference  Fats compared
Brake (1990) PF
Brake et al. (1989) PF
Denbow & Hulet (1995) SBO, PF, FO
Peebles et al. (1999a, b) CO, PF, LA
Peebles et al. (2000a) PF, CO, LA
Peebles et al. (2000b) PF, CO, LA
Fats: PF – poultry fat; SBO – soybean oil; FO – fish oil; CO – corn oil; LA – lard 


Summary
Over and undersupply of nutrients into and through lay can have a very significant impact on breeder production and quality of progeny. This places greater emphasis on the nutritionist providing the correct nutrient density diet and the flock manager to provide appropriate feed allocation in lay.

Addition of micronutrients to the breeder has been shown to be beneficial to progeny quality especially in the early production period. Use of specific dietary ingredients such as maize can affect breeder performance and progeny quality. Both on economic grounds and on biological grounds, high quality nutrition of breeders is well justified.

Source: Aviagen - June 2007

[mikey]

A Health Program for Small and Specialty Poultry Flocks
By The University of Maryland - This article looks at setting up and managing small flocks.

Practice Confinement Management. Always keep your poultry housed or in a fenced area. Never let poultry or other fowl run loose. Try to eliminate all contact between domestic poultry and free-flying waterfowl or other wild birds. Dead birds should be burned or buried at least one foot deep or properly composted.*

Avoid Mixing Types. Keep wild or tame waterfowl, cage or pet birds, ratites, and any other exotic birds on separate premises from chickens, turkeys and game birds. If this is not possible, maintain in separated, nonconnecting pens. It is important to raise all species separately, if possible, to minimize the spread of disease.

Wild waterfowl are reservoirs of avian influenza and other diseases; mixed-species poultry operations can serve as a catalyst for virus mutation and increase the risk for disease outbreaks. Just as chickens and turkeys should not be kept together, so should web-footed birds (ducks, geese and other waterfowl) be kept away from non-web-footed birds such as chickens, turkeys, game birds, etc.

Control Human Traffic. Lock doors. Allow visitors only after they have put on properly sanitized footwear, clothing and hats. Change clothes and footwear before leaving home and upon returning to your premises. Do not transfer fecal material and dust to or from your flock.

No Unsanitary Crates, Equipment or Vehicles. Insist that all buyers of poultry bring only clean, disinfected crates, equipment and vehicles onto your farm, with no visible fecal material or feathers.

Better yet, take your birds to a predetermined location. Clean your hauling equipment before returning home. Remember, one speck of fecal material or a feather can carry billions of infectious germs.

All In, All Out. Process the entire flock at least every 12 to 15 months when possible. Freeze the meat for later consumption.

Wash and disinfect the poultry house. Then leave it empty for two weeks. Replace flock with healthy chicks from a single source. Do not add any new stock until the next cleanup. Limit the number of different age groups on your farm.

When all-in, all-out is not possible, bring new stock onto your farm only by hatching fertile eggs that you have purchased, or by buying Pullorum-Typhoid Clean chicks. Adult birds can be disease carriers, even if they appear healthy.

Nutrition. Fresh, clean feed and water should be available at all times. Keep feeders and waterers clean. Use feeds that are balanced for the species being raised. For example, do not feed turkey feed to laying hens, chicken feed to game birds, or cattle feed to poultry.

Generally, day-old to 21-day-old birds, and birds under stress-- such as from moving and severe weather changes-- can benefit from vitamins and electrolytes added to their drinking water.

Health Specifications. Insist that (1) replacement chicks have been vaccinated against Marek’s disease; (2) all chickens, turkeys, game fowl or waterfowl purchased are officially classified as U.S. Pullorum-Typhoid Clean. Participate in avian influenza testing programs where available.

Medication. Feeds used for day-old to eight-week-old turkeys and day-old to 16-week-old floor- or range-reared chickens should include a coccidiostat. After turkeys are eight weeks old, a blackhead preventative should be added to their feed. Nitarsone with bacitracin at low levels is the only medication cleared for prevention of blackhead.

According to law, a number of medications, including anticoccidial drugs, have a withdrawal time before meat or eggs can be consumed. Read and follow all label directions. For additional help, consult with your local veterinarian, county Extension educator or feed dealer.

* Burial and incineration subject to local environmental regulations. Check with your state Department of Agriculture representative.

Source: University of Maryland College of Agriculture and Natural Resources - August 2004