精补料增重净能对西杂肉牛育肥性能和成本的影响

Effect of dietary net energy for gain on finishing performance and cost of Simmental crossbred beef cattle

选择48头体重相近([192.90±26.38)kg]的8~10月龄西门塔尔杂交肉牛随机分为4个试验组,通过添加大豆油饲喂按等同梯度从5.94 MJ/kg递增到6.57 MJ/kg增重净能的等同蛋白质和必需氨基酸的精补料,探讨4组高增重净能的精补料饲喂杂交肉牛的育肥性能和成本。150 d育肥试验的结果表明,饲喂6.36 MJ/kg增重净能精补料3和5.94 MJ/kg精补料1的杂交肉牛全期日增重分别为1.26 kg和1.19 kg,精料重比分别为2.95和3.16,增重耗精料成本占摄入成本分别为79.53%和84.51%(P<0.05、P<0.01),显著差异来自精补料增重净能的二元曲线效应;饲喂6.57 MJ/kg增重净能精补料4和6.15 MJ/kg精补料2的杂交肉牛全期育肥性能在数据上优于精补料1和低于精补料3(P>0.05)。由此结论,在饲喂黄贮玉米秸秆条件下,6.36 MJ/kg增重净能的精补料3明显提高杂交肉牛育肥性能、饲料效率和育肥利润空间;过高增重净能的精补料4没有表现出最佳育肥效果。

A trial was conducted to evaluate the effects of increasing dietary net energy for gain(NEg)concentration on performance and profit margin of finishing Simmental crossbred beef cattle under the same condition of the dietary crude protein or essential amino-acid concentration.48 Simmental crossbred beef cattle [average BW=(192.90±26.38) kg] at the age of 8~10 months fed four diets whose NEg increased from 5.94 MJ/kg to 6.57 MJ/kg by an equal gradient with supplementing soybean oil.After 150 d finishing period,the average daily gain,feed:gain and percentage of dietary cost per kg gain in daily intake were 1.26 kg vs.1.19 kg,2.95 vs.3.16 and 79.53% vs.84.51% for the cross-bred beef cattle fed 6.36 MJ/kg NEg diet 3 and 5.94 MJ/kg NEg diet 1,respectively(P<0.05,P<0.01).The significance is the quadratic effect.The cross-bred beef cattle fed 6.57 MJ/kg NEg diet 4 or 6.15 MJ/kg NEg diet 2 had no significance in performance compared with the other two diets(P>0.05).It was concluded that the cross-bred beef cattle fed 6.36 MJ/kg NEg diet 3 had a significant increase in finishing performance,feed efficiency and the profit margin under the condition of feeding cornstalk silage.The highest NEg diet 4 did not show the best results.