According to the physiological characteristics and growth and development requirements of broilers, the rearing period can be divided into several stages. Different levels of diets and management methods can be used to improve the feeding effect, so that the feeding regulations can be more reasonable, and feed costs can be saved and production can be reduced. cost. This feeding method is called segment feeding and it includes feed segmentation and management segmentation. (1) Feed segmentation There are two-stage and three-stage systems for the current feeding of broilers. Foreign broiler raising standards generally use three-stage system, such as the United States NRC feeding standards divided into three sections according to 0 ~ 3, 4 ~ 6, 7 ~ 9 weeks of age. The recommended amount of AA broilers in the United States is from 0 to 21 days, 22 to 37 days, and 38 days to the market and is divided into the previous material, medium-term material, and late material. In the early period, it was also called chicken material, and its protein level was relatively high (21%~23%), and it contained disease-preventing drugs. The medium-term material was also called growth chicken material. Compared with the previous material, the protein level decreased and the energy increased; Also known as fertilization, the protein level is lower, but the energy level is increased, and the use of drugs and growth promoters is prohibited. The yellow broiler chickens in China are usually divided into two or three stages depending on the date of slaughter. According to this, the feed supply for the three yellow chickens is also divided into two or three types. (2) Management segmentation For the convenience of management, broilers are generally divided into three stages: brooding period, growth period and fattening period. The brooding stage has strict requirements on the ambient temperature; in the medium period, the broiler chicken rapidly grows, and the broiler chicken grows particularly quickly at this stage, which is also known as the growth period; in the later period, the larvae are slaughtered before the slaughter. Anesthesia Medical Co., Ltd. , https://www.jssinoanesthesia.com