Feeding management of laying hens before and after opening the pen is very important. If the feeding management is proper, the laying rate of chickens can reach the standard curve in time. Therefore, the following aspects should be done well before and after the chicken is opened: ① Increase the light. The principle of illumination after chicken gut opening is that it can only be prolonged but not shortened. The extension of illumination time should be based on the body weight measured at 18 or 20 weeks old. If the average weight of chickens reaches the standard, the light time will be gradually increased every week from 20 weeks old until it reaches 15 ~ 16 hours. If the weight standard is still not reached at the age of 20 weeks, the supplementary light time can be delayed by 1 week, that is, 26438. By gradually increasing the light, hens can be stimulated to start laying eggs in time and reach the expected peak of laying eggs. ② Supplement calcium and change diet. Premature calcium supplementation in growing chickens is not conducive to calcium deposition in hen bones. This is because during the reproductive period of hens, some small spicules cross each other from the inner wall of bone cavity, which looks like cancellous bone. The gap between them is filled with red bone marrow and blood sinus, which is called medullary bone, and has the function of storing calcium, but it does not have these physiological characteristics during the growth period. After laying eggs, the calcium stored in bone marrow is mobilized and reaches the eggshell gland in uterus through blood circulation, participating in the formation of eggshells. The storage of bone calcium in hens is basically in dynamic balance. Under normal circumstances, there are enough calcium reserves in hen bones to form several eggs. Usually, after the bone calcium reserve is mobilized, it can be supplemented by feeding. When you don't get enough calcium from feed, the quality of eggshells will deteriorate, soft-shelled eggs or eggshells will be produced, and even hens will be paralyzed. Hens tend to feel calcium deficiency during eggshell formation at night. In the first half of the light, the calcium ingested by chickens passes through the digestive tract, is absorbed in the small intestine, enters the blood, is deposited in the bones, and is then used to form eggshells when necessary. Only the calcium ingested in the second half of the day is directly used to form eggshells. Bone meal, shell meal and stone meal are widely used calcium sources, and the eggshell strength is the best when the ratio of shell meal to stone meal is 2∶ 1. Chickens have the best absorption of animal calcium sources, but the absorption of plant calcium sources is poor. Eggshells sterilized at high temperature are the best source of calcium. The calcium supplement time can start from 18 weeks, which can increase the calcium content of chicken feed from 1% to 2%. When the laying rate of the whole group of hens reaches 5% (the ideal group should be 20 weeks old), the feed for growing chickens is changed to that for laying hens, and then the calcium level in the feed is further increased to 3.2% ~ 3.4%. Insufficient calcium in feed will lead to poor eggshell quality. ③ Keep the henhouse quiet. When the chicken is sexually mature, it is the beginning of a new life stage, especially when it lays the first two eggs, showing high mood, abnormal behavior and nervousness. Therefore, in the early stage of delivery, we should try to avoid disturbing the chickens and create a quiet environment. (4) Increase the feed rate according to the weight change. When the laying rate reached 50%, the weight of laying hens still increased rapidly in the first 2 ~ 3 weeks and after 1 ~ 2 weeks. For example, from the age of19 to 23 weeks, the weight of Roman brown and Dika brown increased by 240 g and 320 g respectively, and the amount of feed needed to maintain their weight increased continuously. Coupled with the nutrients needed for spawning, the feeding amount needs to be greatly increased at this stage. See Table 6-7 for the daily feeding amount of chickens.