高温环境下饲粮营养水平对黄羽肉鸡生产性能和胴体组成的影响

THE EFFECT OF DIETARY NUTRIENT DENSITYON PERFORMANCE AND CARCASS COMPOSITI ON OF YELLOW BROILERS UNDER HIGH TEMPERATURE

本试验选取21日龄健康快大型岭南黄羽肉鸡450只,随机分为3组,每组3个重复,每重复50只鸡(公母各半),室温27～36℃。第1组饲喂黄羽肉鸡常规营养水平饲粮,作对照组;第2组饲粮营养水平提高5%;第3组饲粮营养水平提高10%。试验期42天。试验结果表明,饲粮营养水平提高5%显著提高了试鸡21～42日龄阶段饮水量(P<0.05),饲粮营养水平提高10%使试鸡21～42日龄阶段采食量显著降低(P<0.05),饲料转化率显著提高(P<0.05),43～63日龄阶段平均日增重显著提高(P<0.05),整个试验阶段的饲料转化率显著提高(P<0.05)。提高饲粮营养水平降低试鸡试验第1周(P=0.0237)、第6周体温(P=0.0013)和第6周呼吸数(P=0.0093)。饲粮营养水平提高5%组试鸡42日龄血清尿素氮含量降低20.45%(P>0.05),饲粮营养水平提高10%组试鸡42日龄、63日龄血清尿素氮含量分别降低15.91%、18.82%(P>0.05)。提高饲粮营养水平降低试鸡腿肌(P=0.0001)和胸肌的水分含量(P=0.001),提高试鸡腿肌的脂肪含量(P=0.0013)。综合试验结果认为,高温环境下提高饲粮营养水平能提高试鸡的生长性能,改善体成分,其中营养水平提高10%组好于5%组。

Four hundred fifty Lingnan Yellow broilers,at the age of 21 days old,were divded into 3 groups for 6 weeks to study the effects of dietary nutrient density on performance and carcass composition of yellow broilers under high temperature.A factorial arrangement of three level of nutrition(normal nutrient level,group 1;5% high nutrient level,group 2;10% high nutrient level,group 3)was used in this study.Groups of bird was kept under hot cycling temperature(25～28℃/6h,28～36℃/6h and 25～28℃/6h).The results indicated that high nutrient density significantly(P <0.05) increased water intake,feed intake,decreased feed convertion(feed:gain) between 21 and 42 days of age,increased average daily weight gain between 43 and 63 days of age,decreased feed convertion(feed:gain)between 21 and 63 days of age.High nutrient density significantly(P<0.05) decreased body temperature at 4 and 9 weeks,respiration rate at 9 week,water content of thigh and breast meat,but increased thigh fat(P=0.0013).It is concluded,under the conditions imposed in this experiment,that increasing nutrient density improved the performance of the broilers.