补饲不同蛋白水平日粮对北川白山羊生产性能和屠宰性能的影响

Effects of Different Dietary Protein Levels on Production and Slaughter Performance of Beichuan White Goat

本试验旨在研究放牧补饲不同蛋白水平日粮对北川白山羊生产性能和屠宰性能的影响。选择60只(6月龄)北川白山羊作为研究对象,随机分成4组,即14%蛋白组、16%蛋白组、18%蛋白组和对照组(不补饲),每组15只,测定生产性能、血液生化指标和屠宰性能。结果显示:补饲组北川白山羊平均日增重、血清总胆固醇、尿素氮含量、葡萄糖含量、谷草转氨酶活性、宰前活重、胴体重、屠宰率、眼肌面积以及羊肉粗蛋白含量均显著高于对照组(P<0.05)。随着补饲蛋白水平的增加,血清尿素氮含量呈线性增加(P<0.05),而羊肉水分含量呈线性减少(P<0.05);平均日增重、血清总胆固醇含量、血清葡萄糖含量和羊肉粗蛋白呈二次曲线变化(P<0.05)。结果表明:补饲不同蛋白水平日粮可以提高血清中血糖、尿素氮、总胆固醇浓度和谷草转氨酶活性,可以在一定程度上改善和提高北川白山羊的生产性能、屠宰性能及肉品质等,北川白山羊的补饲料适宜蛋白水平为16%。

This experiment aimed to study the effects of dietary protein levels on the production and slaughter performance of Beichuan White goat.Sixty healthy Beichuan White goat aged about 6 months were selected and assigned randomly to four groups:14%,16% and 18%crude protein(CP)groups and control group(without supplementary feeding),with 15 goats in each group.The production performance,blood biochemical index and slaughter performance were measured.The results showed as follows:the average daily gain,serum total cholesterol,urea nitrogen,glucose,glutamic oxalacetic transaminase activity,pre-slaughter live weight,carcass weight,slaughtering rate,eye muscle area and mutton crude protein content of Beichuan White goat were all significantly higher than those of the control(P<0.05).With the increase of dietary protein level,serum urea nitrogen content increased linearly(P<0.05),the water content of mutton decreased linearly(P<0.05),while the average daily gain,serum total cholesterol,serum glucose and crude protein of mutton presented conic curve changes(P<0.05).These results indicate that dietary supplementation with different protein levels can increase serum blood sugar,urea nitrogen,total cholesterol concentration and activity of glutamate transaminase,which can improve the production performance,slaughtering performance and meat quality of Beichuan White goat to a certain extent.The optimum protein level in the diet of Beichuan White goat is 16%.