It depends on the recommendation of the feed manufacturer. Every feed manufacturer have a feeding program that you should follow.
As a rule of thumb give first small quantities. If they can easily finish it then give again.
As long as they want to eat then give them feeds.
To give you an idea:
This is taken from the pamphlet of ACE FEEDS feeding program
Type of feeds booster pre starter starter grower finisher | | age of animal 6-35 36-60 61-90 91-120 121-up to market | | kg of feed per day 0.10 0.60 1.20 2.2 2.8 |