Most production houses for broiler breeders are equipped with a system to exclude the males from the female feeders. This is usually a grill over the feeder track or pan, but also a tube or board over the track is used. It is important that the space between track and board or tube or size of the grill is big enough to let the biggest female eat, also later in production, to avoid that the bigger birds are getting restricted.
However, this often means that during start of production the smaller males are still able to eat from the female feeder. Although there are individual differences between breeds and flocks, we normally see that the male excluding system on the female feeder is fully effective from approximately 26-27 weeks of age, although even at a later age an individual male might be able to get into the female feeder.
To control the body weight and growth of the males, it is important to correct the male feed amount in this period for the amount of feed that they are stealing from the female feeder. One way of doing that is to estimate regulary what percentage of males is still eating from the female feeder, and deduct that percentage from the male feed ratio and add it to the female feed amount. This must be checked regulary (at least once but preferably twice a week) as the ratio of males eating from the female feeder changes rapidly. However, males are eating approximatley twice as fast as females, so we actually have to deduct a bit more feed from the male feeder than strictly indicated by the percentage of males eating from the females. This requires some experience, but it means we should not be too afraid to deduct feed from the males in that period, and we should keep a close eye on body weight development, condition and behavior of the males, as the picture can change rapidly.
We can also look at the body weight development of the males and steer the male feed amount based on that. Downside of this method is that it takes a while before the males react with body weight (growth) on the changing amount of feed, so by the time we see that the males are not growing fast enough anymore we are already late in our reaction.
Whatever method we practice, we must be aware that in the period until 26-27 weeks some males will eat with the females, and to avoid excessive growth in this period we should correct the feed amount for this "stealing".