Feed formulation- square method

THis is used by novice animal nutritionist as a starting point in the study of feed formulation. You can compute the proper mix of ingredients to attain a certain amount of CP or crude protein.

example.

If you have corn and soya. (CP of certain ingredients sometimes varies depending on the book you have as a reference.)

Assuming Corn has 11% CP while soya 44% CP or crude protein. In a prestarter ration (swine) you need a 21% crude protein mix, so, how many part of corn and soya should i mix to attain 21% crude protein.

the 23 parts is attained by subtracting 21 CP with the CP of the soya which is 44.

the 10 parts is attained by subtracting the 21 CP with the CP of corn which is 11

33 is attained by adding the 23 parts to 10 parts.

following the formula we attained 69.7% parts corn and 30.3% parts soya.

So if we want a 50 kg feed with 21% crude protein:

50 kg x 69.7 =3485/100= 34.85 kg corn

50 kg x 30.3%=1515/100= 15.15 kg rice bran

total 50 kg of feeds with 21% CP

NOTE: there should be no negative number in the formula. Example if you use soya with a 44 % CP. and your target is 21%CP , 21-44= -23. drop the negative sign. it should be 23 parts only.

***** I have edited the former data because there should be a value that is higher than the desired CP. On the previous example both source of CP are below the desired CP.... Sorry for mistake. I have overlooked the values.... THe principle is still the same as the previous post....