What are the key management points for broiler breeder chickens during the rearing period?

Broiler breeder breeds have characteristics such as strong feed intake capacity, rapid growth and development, vigorous metabolism, easy fat deposition, and inconsistent development of various body systems. If they are allowed to feed freely during the rearing period, on the one hand, the chickens will become overweight and too large, and the locomotor system, reproductive system and overall development will be uncoordinated, reducing the rearing rate, increasing the mortality and culling rate, reducing egg production of hens after rearing, increasing the number of deformed eggs, and resulting in poor fertilization ability of roosters. Therefore, in order to prevent the chickens from becoming overweight and too large, coordinate the consistency between sexual maturity and physical maturity, and effectively control the average body weight of the flock, restricted feeding (feed restriction) must be implemented.

I. Restricted feeding

1. Methods The degree of feed restriction is mainly based on conditions such as the average body weight of the flock, health status, feed nutritional level and environmental factors, and the feed supply is adjusted weekly to meet the nutritional needs for weekly weight gain of the flock. There are mainly 3 methods: ① Daily restricted feeding method, that is, the amount of feed needed for the flock's weight gain in the current week is averaged over each day and given in one feeding; this method is suitable for flocks from 4 to 7 weeks of age and after 20 weeks of age; ② Skip-a-day restricted feeding method, that is, feeding once every 2 days, giving in one feeding the amount of feed for two days needed for the flock's weight gain in the current week; this method is suitable for flocks from 7 to 12 weeks of age; ③ "Two-five" restricted feeding method, that is, within each week there are 2 days without feed (the no-feed days must be separated from each other) and 5 days with feed; on each feeding day, the feed must be given in one feeding, and the feed amount is 1/5 of the total feed amount needed for the flock's weight gain in the current week; this method is suitable for flocks from 15 to 19 weeks of age.

2. Key points During the rearing period, feed restriction for broiler breeders should mainly focus on two technical indicators, namely the average body weight and uniformity of the flock:

① Average body weight is the main indicator for measuring the weight gain of the flock. Sampling and weighing during the rearing period of broiler breeders is a tedious, meticulous and very important task in feed restriction, and it is one of the important indicators for measuring the effect of feed restriction. Weigh the chickens on an empty stomach at the end of each week, randomly select 5%-10% of the whole flock, weigh them one by one, calculate the average body weight, and use this as the basis for determining the feed supply for the flock in the next week; generally, a weekly feed increase of 3-5 g per bird is appropriate. If the body weight exceeds the standard, increase the feed less or not at all, but do not reduce the feed; if the body weight is below the standard, increase the feed appropriately, but it should not exceed 10 g per bird. Any change in the feeding program should refer to the flock's average body weight, bone size, degree of fatness and feather coverage over 2-3 consecutive weeks.

② Flock uniformity is an important indicator for measuring developmental differences among individuals within the flock. In management, it is generally relatively easy to achieve body weight control targets, but it is not so easy to obtain replacement breeder chickens with high uniformity (body weight uniformity and sexual maturity uniformity). Body weight uniformity is measured by the percentage of the number of birds within the range of "average body weight ±15%" in the total number sampled. In the late rearing period, a flock uniformity above 80% is considered a qualified flock. We should carry out weighing of the whole flock and grouping by strength around 4 weeks of age, before the flock's body weight uniformity shows a downward trend, and then carry out another whole-flock weighing and grouping before the end of 8 weeks and 12 weeks. In this way, uniformity at 15 weeks will reach a very high level, which is conducive to later body weight control and uniform sexual maturity development. After 15 weeks, effective control of body condition and sexual maturity uniformity is mainly achieved through uniform increases in weekly weight gain.

II. Do a good job in other management

Ensure high-quality diet and drinking water; carry out grouping in a timely manner, with small groups preferably 400-500 birds; maintain appropriate density, 8-10 birds per sq m from 7 to 15 weeks of age, and 3.6-4.8 birds per sq m after 16 weeks of age; provide sufficient feeding space, with trough space not less than 10 cm per bird from 7 to 15 weeks of age, maintain good environmental control conditions and litter and lighting management; regularly carry out drug prevention.

In short, to achieve the work goals for broiler breeders during the rearing period, it is necessary to do a good job on the two tasks of average body weight and uniformity of the flock. Correct weighing, accurate calculation, standard feeding, sufficient trough space and rapid feeding, maintaining good body condition and uniformity of the flock, and cultivating healthy and qualified replacement flocks will provide a strong guarantee for better exerting excellent production performance during the laying period.