玉米和玉米青贮日粮添加赖氨酸对肉牛生长性能及血液生化指标的影响

选择56头利木赞F_1杂交公牛,研究赖氨酸添加水平对肉牛生长性能及血液生化指标的影响。试验动物随机分为4组,每组14头,分别饲喂添加不同梯度的过瘤胃赖氨酸(0、5、10 15 g/d和15 g/d)日粮。结果表明:日粮中赖氨酸添加量对肉牛的采食量没有显著影响(P>0.05),对日增重(P=0.036)和饲料转化率(P=0.030)具有二次曲线影响,其中赖氨酸的添加量为10 g/d时,肉牛日增重最大,饲料转化率最高。随着赖氨酸添加量的增加,血液尿素氮(P=0.014)和胰岛素(P=0.022)呈二次曲线变化,但对其他血液生化指标没有影响。本试验结果表明,对于以玉米和玉米青贮为基础日粮的肉牛来说,10 g/d为过瘤胃赖氨酸的最适添加量。

Effect of Supplementation of Rumen-Protected Lysine on Growing Performance and Blood Biochemical Indices of Beef Cattle fed Cornstalk Silage/corn Grain-Based Diet

The effects of rumen-protected lysine(RPL) supplementation on growth performance and blood biochemical indices were investigated using 56 Limousin F_1 crossbred bulls fed a cornstalk silage/com grain-based diet.Incremental amounts(0,5,10 or 15 g/d) of RPL were added to the basal diet.Increasing supplemental RPL level did not alter dietary DMI(P=0.288),but quadratically increased average daily gain(ADG)(P=0.036) and gain efficiency(P=0.030).The maximum ADG and gain efficiency were achieved at the addition of 10 g/d RPL.Supplementing dietary RPL caused quadraticlly decreased plasma urea nitrogen(PUN)(P=0.014) and quadratically increased insulin(P=0.022).However, RPL supplementation had no effect(P>0.05) on the other blood biochemical indices.In conclusion,10 g/d rumenprotected lysine supplementation is optimal for beef cattle fed cornstalk silage/corn grain-based diet.