发酵杂粕型饲粮添加小肽对肉牛生长性能、养分表观消化率及血清生化指标的影响

本试验旨在研究发酵杂粕型饲粮中添加小肽对肉牛生长性能、养分表观消化率及血清生化指标的影响,探索发酵杂粕型饲粮中小肽适宜的添加水平。试验选取初重为(481.43±36.36) kg、健康状况良好的肉牛28头,随机分为4组,每组7头牛,分别饲喂小肽添加水平为0(Ⅰ组)、0.5%(Ⅱ组)、1.0%(Ⅲ组)和1.5%(Ⅳ组)的全混合日粮。预试期25 d,正试期60 d。结果表明:1)随着小肽添加水平的增加,平均日增重有二次曲线变化的趋势(P=0.062),料重比呈二次曲线变化(P<0.05),Ⅲ组平均日增重最高、料重比最低。2)有机物消化率随着小肽添加水平的增加呈二次曲线变化(P<0.05),Ⅲ组粗蛋白质表观消化率显著高于Ⅳ组(P<0.05),有二次曲线变化的趋势(P=0.087)。3)随着小肽添加水平的增加,血清丙谷转氨酶、谷草转氨酶活性和尿素氮含量呈二次曲线变化(P<0.05),血清总胆固醇和葡萄糖含量有差异显著的趋势(P=0.096, P=0.055)。综上所述,在本试验条件下,发酵杂粕型饲粮添加小肽能改善肝脏功能,提高养分表观消化率和生长性能;小肽添加水平以1.0%为宜。

Effects of Small Peptide Supplementation in Diets with Fermented Mixed Meals on Growth Performance,Nutrient Apparent Digestibility and Serum Biochemical Indices of Beef Cattle

This study was to investigate the effects of small peptide supplementation in diets with fermented mixed meals on the growth performance,nutrient apparent digestibility and serum biochemical indices of beef cattle,explored the appropriate supplementation level of small peptides in diets with fermented mixed meals.Twenty-eight healthy Simmental crossbred cattle(481.43±36.36)kg of initial weight]were randomly divided into 4 groups with 7 cattle in each group,and were fed total mixed ration diets with small peptide supplementation levels with 0(groupⅠ),0.5%(groupⅡ),1.0%(groupⅢ),and 1.5%(groupⅣ),respectively. The pre-test period lasted for 25 days and the trial lasted for 60 days. The results showed as follows:1)with the increase of dietary small peptide levels,the average daily gain of beef cattle presented a tendency quadratic curve(P = 0.062),and the feed/gain showed a quadratic curve(P<0.05),groupⅢhad the highest average daily gain and the lowest feed/gain. 2)The apparent digestibility of organic matter had a quadratic curve with the increase of the levels of small peptide(P<0.05);and the apparent digestibility of crude protein of groupⅢwas significantly higher than that of groupⅣ (P<0.05),and it showed a tendency of quadratic curve(P = 0.087). 3)With the increase of dietary small peptide levels,the activities of alanine aminotransferase,aspartate aminotransferase and the content of urea nitrogen were increased in a quadratic curve(P <0.05),and the contents of total cholesterol and glucose presented a tendency of difference(P = 0.096,P =0.055). In conclusion,small peptide supplementation in diets with fermented mixed meals can improve liver function,increase nutrient apparent digestibility and growth performance of beef cattle. Under the conditions of this study,and the appropriate level of small peptides in diets with fermented mixed meals of beef cattle is1.0%.Chinese Journal of Animal Nutrition,2022,34(2):1058-1066]