日粮同步释放指数对羔羊生长性能和主要消化器官发育的影响

Effects of Synchronizing Nitrogen and Carbohydrate on Growth and Development of Digestive Organs in Small Tail Sheep

目的:研究日粮碳氮协同释放指数对羔羊生长和主要消化器官发育的影响,为利用同步释放指数优化日粮结构提高动物生产性能提供参考依据。方法:利用尼龙袋试验,测定不同饲料原料中的氮与碳水化合物在瘤胃中每小时的有效释放量。在此基础上,利用指数计算公式优化日粮组构,使日粮中氮与碳水化合物在瘤胃中的协同释放指数分别达到0.58、0.71、0.84。选择60只体重相近且健康的小尾寒羊羔羊作为试验动物,将其平均分为3组,每组分别饲喂不同指数的日粮。试验期为60天,动物自由饮水和采食。试验结束后每组随机选择5只进行屠宰,分别测定其生长性能、屠宰性能以及胃肠道指数。结果:增加瘤胃可利用氮和碳水化合物协同释放指数,能够提高肉羊的日增重和前胃重量。当瘤胃可利用氮和碳水化合物同步释放指数为0.71时,羔羊的净骨率有增加的趋势(P=0.055),但肉骨比显著降低(P=0.038)。提高瘤胃可利用氮和碳水化合物同步释放指数,能够线性提高瓣胃(P=0.018)和皱胃(P=0.027)重量及十二指肠(P<0.001)和回肠指数(P<0.001)。结论:通过提高瘤胃可利用氮和碳水化合物同步释放指数,有利于促进瘤胃和小肠等消化器官的发育。

Objective:Based on the ruminal release of both nitrogen and carbohydrate.The effects of synchronizing nitrogen and carbohydrate was investigated on growth and development of digestive organs in small tail ewes by optimizing ingredient composition of the diet.Methods:The nylon bag technique was used to determine the hourly release of nitrogen and carbohydrates of feed ingredients in the rumen.Achieving this,the ingredient composition of the diet was optimized,and the synchrony index with 0.58,0.71 and 0.84 was calculated.Sixty small tail ewes were randomly distributed to three groups with twenty ewes of each,and the ewes had ad libitum access to the diet and water.The experiment lasted sixty days,and five ewes from each group were randomly selected and slaughtered to assess the effects of synchronizing nitrogen and carbohydrate on growth and development of digestive organs in small tail ewes.Results:It is showed that increasing dietary synchrony index increased daily body gain and forestomach weights.The proportion of the bone tended to increased(P=0.055),but the ratio of meat to bone decreased(P=0.038)in ewes fed diet with synchrony index of 0.71.Increasing dietary synchrony index linearly increased the weight index of omasum(P=0.018),abomasum(P=0.027),duodenum(P<0.001)and ileum(P<0.001)in ewes.Conclusion:It is indicated that increasing the dietary synchrony index between nitrogen and carbohydrate in the rumen was beneficial for growth and digestive organs development of small tail ewes.