Feeder space and feed distribution are important tools to rear an uniform flock of broiler breeders. As the birds are severely restricted, a high competition for the available feed occurs in a flock. Without a good feed distribution and sufficient feeder space the smaller or less agressive birds will not get their share of the available daily feed amount, and uniformity will suffer. When the feeder space is limited often non-feed days are used, to enlarge the quantity of the feed on the feed days and give the smaller birds more chance. As the competition after a non-feed day will be higher and the stress on the birds will increase, this often has a negative effect and is therefore not advisable.
As a full grown breeder bird is approximately 15 cm wide when measured over the shoulders, a feeder space of approximately 15 cm per bird should be available at the end of rearing and in production. However, this feeder space is not needed from the start, as the birds are smaller. It is also not very practical to use the full 15 cm from the start, as the feed amounts at the beginning of rearing are very small. It is therefore not possible/practical to use the full amount of the available feeder space, either feed chains or pans, to avoid that big parts of the feeding system will remain empty during feeding.
Both with pans and with chains, we have to determine how much feeder space have to be used at a specific age, to allow enough space for the birds.
When we use pans, we often can calculate it from the amount of feed that is needed to fill up the cone of a pan when the feed opening is set on minimum. There are differences between different types of pans, but most pans need about 800 to 1000 gram to fill up the cones. With this amount we can estimate how much pans we can use. If the total amount of feed is 50 gram/bird and we have 10,000 birds per house, we feed 50 x 10,000 is 500 kg of feed per day. If a pan needs 1000 gram to be filled, we can use 500 pans (500 kg / 1 kg), and these 500 pans should have enough feed places for all the birds to eat, which means 20 birds per pan (10,000 / 500). This shows that in rearing it is beneficial to use pans with the smallest possible cones. If the pan is filled with 800 gram, we can use 500 kg / 0.8 kg = 625 pans, and the number of birds per pan will be 10,000 / 625 = 16 birds per pan, so more feeder space per bird. This assumes a complete equal distribution of the feed, for instance by feeding in the dark. Field conditions are often too challenging to allow a complete equal distribution, but it shows the principle.
When we use a feed chain, it is more about how much feeder space a bird needs, so how wide a bird is over the shoulders at different ages.
There is no real standard for this, but a workable standard that we can use is that a flock up to 5 weeks of age needs 5 cm or feeder space per bird, up to 10 weeks of age needs 10 cm of feeder space per bird, and after 10 weeks needs 15 cm of feeder space per bird. When using feed chains we can only work with using or not using circuits of feed chain in the house, so it will not always be possible to use exactly these dimensions.
If we have for instance 15 cm per bird with 8 feed chains (4 circuits), it is obvious that we cannot limit the number of feeder chains to get to exactly 5 or 10 cm per bird. When all the chains are in use and would add up to 15 cm of feeder space, 1 meter of feeder chain would host 100 cm / 15 cm per bird = 6.7 bird per one side of a meter of feeder chain, so roughly 13 birds per meter of feeder chain (both sides). If we have 8 chains (4 circuits) available, we can host maximum 13 x 8 = 104 birds per m1 of length of the house. If we use one circuit less we have 6 chains available, which means 12 m of feeder space (each chain used on both sides) for 104 birds = 1200 / 104 = 11.5 cm per bird. If we use two circuits less it would be 4 chains or 8 m of feeder space for 104 birds so 800 / 104 = 7.7 cm feeder space per bird. In such a situation we cannot use the exact numbers of 5 cm at 5 weeks and 10 cm at 10 weeks, but we can use two circuits (7.7 cm / bird) up to 7-8 weeks, and 3 circuits (11.5 cm / bird) upt to 11 weeks, and give all the feeder space after that age.