日粮苯丙氨酸水平对0～4周龄泰和乌鸡生产性能及组织黑色素含量的影响

为研究日粮苯丙氨酸水平对泰和乌鸡生产性能和组织黑色素含量的影响。选用1日龄泰和乌鸡108只,随机分成3组,每组设3个重复,每个重复12只鸡(公母各半),饲养至4周龄。试验鸡组分别饲喂3种苯丙氨酸水平的日粮,日粮苯丙氨酸水平分别为0.73%、1.00%和1.27%。结果表明:日粮苯丙氨酸水平显著影响0~4周龄泰和乌鸡平均日增重(P<0.01),其中1.27%组日增重极显著高于0.73%组(P<0.01),显著高于1.00%组(P<0.05);1.00%组显著高于0.73%组(P<0.05)。但日粮苯丙氨酸水平对泰和乌鸡的饲料转化效率(料重比)和平均日采食量无显著影响(P>0.05)。胸肌黑色素含量随着日粮苯丙氨酸水平的提高而降低,1.27%组胸肌黑色素含量极显著低于0.73%和1.00%组(P<0.01),但0.73%和1.00%两组之间无显著差异(P>0.05)。尽管腿肌和皮肤黑色素含量在各组之间不存在显著差异(P>0.05),但黑色素含量有随日粮苯丙氨酸水平提高而增大的趋势。

Effects of Dietary Phenylalanine Levels on Performance and Melanin Contents in Tissues of Taihe Silky Fowls from 0 to 4 Weeks Old

This study was conducted to investigate the effects of dietary phenylalanine levels on performance and melanin contents in tissues of Taihe silky fowls from 0 to 4 weeks old.A total of 108 one-day-old Taihe silky fowls were randomly allotted to 3 groups with 3 replicates of 12 birds each and were raised to 4 weeks old.The birds were fed diets with phenylalanine levels of 0.73%,1.00% and 1.27%,respectively.The results showed as follows: the average daily weight gain(ADG) of Taihe silky fowls was significantly influenced by the dietary phenylalanine levels at 0-4 weeks old(P<0.01),in which the ADG of 1.27% group was markedly higher than that of 0.73% group(P<0.01) and that of 1.00% group(P<0.05),meanwhile the ADG of 1.00% group was higher than that of 0.73% group(P<0.05).No significant difference was observed in feed to gain ratio and average daily feed intake between groups.The melanin content in pectoral muscle was decreased with the increase of dietary phenylalanine level(P<0.05),in which the melanin content of 1.27% group was very significantly lower than those of groups of 0.73% and 1.00%.The melanin contents in leg muscle and skin were not influenced by the dietary phenylalanine level(P>0.05),but the melanin contents in these two tissues tended to increase with the increase of phenylalanine level.