本试验旨在研究1~63日龄黄羽肉鸡在不同生长阶段饲粮赖氨酸需要量。试验采用2（性别）×5（赖氨酸水平）因子试验设计，选用1、22、43日龄快速（63日龄出栏）岭南黄鸡作为试验鸡，每一阶段的饲养周期为21 d。试验1选取1日龄鸡苗雌雄各750只，雌雄各5个组，每组3个重复，每个重复50只鸡；另取雌雄各120只进行氮代谢试验，雌雄各5个组，每组3个重复，每个重复8只鸡。试验2选取22日龄肉鸡雌雄各800只，雌雄各5个组，每组4个重复，每个重复40只鸡；另取雌雄各120只进行氮代谢试验，雌雄各5个组，每组4个重复，每个重复6只鸡。试验3选取43日龄肉鸡雌雄各800只，分组同试验2。饲粮赖氨酸水平设置如下：1~21日龄，0.93%、1.03%、1.13%、1.23%和1.33%；22~42日龄，0.80%、0.90%、1.00%、1.10%和1.20%；43~63日龄，0.65%、0.75%、0.85%、0.95%和1.05%。通过测定饲粮赖氨酸水平对试鸡生长性能、胴体品质、氮代谢率以及血清生化指标的影响，确定不同性别、日龄黄羽肉鸡饲粮赖氨酸需要量。结果表明：1~21日龄，1.13%赖氨酸水平组雌、雄试鸡平均日增重最高，料重比最低，血清尿酸含量最低。22~42日龄，1.00%赖氨酸水平组雄性试鸡料重比较低，雌、雄试鸡平均日增重随饲粮赖氨酸水平的升高呈现出先提高后降低的规律性变化趋势，并在饲粮赖氨酸水平为1.00%时雌性试鸡表现最佳，同时1.00%赖氨酸水平组雌性试鸡胸肌率最高。43~63日龄，0.85%赖氨酸水平组雄、雌试鸡平均日增重最高、料重比较低，雌性试鸡胸肌率最高。综上，本试验条件下，1~21日龄、22~42日龄和43~63日龄黄羽肉鸡饲粮赖氨酸适宜水平分别为1.13%、1.00%和0.85%。

This experiment was conducted to investigate the dietary lysine requirement for Chinese yellow-feather broilers from 1 to 63 days of age in different growth stages. A 2 (gender)×5 (lysine level) factor test design was adopted in the experiment, and the fast Lingnan yellow chickens of 1, 22 and 43 days of age (slaughtered at 63 days of age) were selected for feeding with three stages of 21 days each. In experiment 1, a total of 750 male and 750 female 1-day-old chickens were selected, and divided into 5 male groups and 5 female groups with 3 replicates in each group and 50 chickens in each replicate. In addition, 120 males and 120 females were selected and divided into 5 male groups and 5 female groups with 3 replicates in each group and 8 chickens in each replicate for the nitrogen metabolism test. In experiment 2, a total of 800 male and 800 female 22-day-old broilers were selected, and divided into 5 male groups and 5 female groups with 4 replicates in each group and 40 broilers in each replicate. In addition, 120 males and 120 females were selected and divided into 5 male groups and 5 female groups with 4 replicates in each group and 6 broilers in each replicate for the nitrogen metabolism test. In experiment 3, a total of 800 male and 800 female 43-day-old broilers were selected and grouped with the same of experiment 2. The dietary lysine levels were set as 0.93%, 1.03%, 1.13%, 1.23% and 1.33% for 1 to 21 days of age, 0.80%, 0.90%, 1.00%, 1.10% and 1.20% for 22 to 42 days of age, and 0.65%, 0.75%, 0.85%, 0.95% and 1.05% for 43 to 63 days of age. The effects of dietary lysine levels on growth performance, carcass quality, nitrogen metabolism rate and serum biochemical indices of broilers were measured to determine the dietary lysine requirement for Chinese yellow-feather broilers with different genders and ages. The results showed that the average daily weight gain of both male and female broilers from 1 to 21 days was the highest, and feed to gain ratio and serum uric acid content were the lowest in 1.13% lysine level group. From 22 to 42 days of age, the feed to gain ratio of male broilers in 1.00% lysine level group was relatively low, and the average daily weight of both female and male broilers showed a regular trend of increasing first and then decreasing with the dietary lysine level increasing, and the female broilers performed the best and had the highest breast muscle rate when the dietary lysine level was 1.00%. From 43 to 63 days of age, the average daily gain of both male and female broilers was the highest, the feed to gain ratio was lower, and the breast muscle rate of female broilers was the highest in 0.85% lysine level group. In conclusion, under the conditions of this experiment, the optimal dietary lysine levels of Chinese yellow-feather broilers at the ages of 1 to 21 days, 22 to 42 days and 43 to 63 days are 1.13%, 1.00% and 0.85%, respectively.