日粮酪氨酸水平对5～8周龄泰和乌骨鸡生产性能及组织黑色素含量的影响

Effects of Dietary Tyrosine Levels on Performance and Melanin Contents in Tissues of Taihe Silky Fowls Aged from 5 to 8 Weeks of Age

研究日粮酪氨酸水平对泰和乌骨鸡生产性能和组织黑色素含量的影响。选用28日龄泰和乌骨鸡随机分成6组，每组设3个重复，每个重复15只鸡，饲养至8周龄。试验鸡组分别饲喂6种酪氨酸水平的日粮，日粮酪氨酸水平分别为0．48％、0．68％0．88％、1．08％、1．28％和1．48％。结果表明：日粮酪氨酸水平显著影响5～8周龄泰和乌骨鸡平均日增重、日采食量和料重比（P〈0．05），且在0．88％水平时显著影响平均日增重、料重比（P〈0．01）。日粮酪氨酸水平极显著影响5～8周龄泰和乌骨鸡组织中黑色素的含量（P〈0．01），随着日粮酪氨酸添加水平的提高组织中黑色素含量先增加后降低。心脏、肌肉、皮肤中黑色素的含量在1．08％水平时达到最高且与0．48％水平组差异极显著（P〈0．01）；而肝脏组织中黑色素的含量在1．28％水平达到最高。

This study was conducted to investigate the effects of dietary tyrosine levels on performance and melanin contents in tissues of Taihe silky fowls aged from 5 to 8 weeks of age. Twenty - eight - day - old Taihe silky fowls were randomly allotted to 6 groups with 3 replicates of 15 birds each and were raised to 8 weeks of age. The birds were fed diets with tyrosine levels of 0.48% ,0.68% 0.88% , 1.08% , 1.28% and 1.48% , respectively. The results showed as follows： The average daily weight gain （ADG）, average daily feed intake （ADFI） and feed to gain ratio （F/G） of Taihe silky fowls were markedly influenced by the dietary tyrosine levels at 5 - 8 weeks of age （ P 〈 0.05 ） and the average daily weight gain （ADG） and feed to gain ratio （ F/ G） of Taihe silky fowls were significantly influenced by the dietary tyrosine 0.88% level （ P 〈 0.01 ）. The melanin contents in tissues increased first and decreased afterwards with the increase of dietary tyrosine levels,the melanin contents in heart,muscle and skin were significandy higher（ P 〈0. 01 ）at the 1.08% level compared with at the 0. 48% level,but the melanin contents in liver was very high at the 1.28% level.