不同水平葡萄籽渣对西门塔尔牛体外产气量、发酵参数、营养物质消化率和生长性能的影响

目的] 研究用不同水平葡萄籽渣替代肉牛精料补充料中部分玉米和棉粕对西门塔尔牛体外瘤胃发酵产气量、营养物质体外消化率、发酵参数及生长性能的影响。方法] 试验采用模拟瘤胃体外培养技术,以4%、8%、12%和16%葡萄籽渣替代肉牛精料补充料中部分玉米和棉粕,测定各组日粮体外产气量、发酵参数、营养物质体外消化率及肉牛生长性能。结果] 随着体外发酵时间的增加,累计产气量呈递增趋势,12%葡萄籽渣组产气量最大,各组之间72 h总产气量差异不显著（P>0.05）;产气后人工瘤胃培养液pH值、NH₃-N浓度和菌体蛋白含量各组无显著（P>0.05）差异,试验组挥发性脂肪酸浓度显著（P<0.05）升高;16%葡萄籽渣组干物质消化率最低,对照组粗蛋白消化率显著（P<0.05）高于试验组,对照组和4%葡萄籽渣组中性洗涤纤维消化率显著（P<0.05）高于其他三组,对照组和12%葡萄籽渣组酸性洗涤纤维消化率显著（P<0.05）高于其他三组;4%和8%葡萄籽渣组肉牛平均日增重较对照组分别高170 g/d和140 g/d。结论] 葡萄籽渣替代肉牛精料补充料中部分玉米和棉粕可以提高瘤胃挥发性脂肪酸含量,添加4%和8%葡萄籽渣可以提高肉牛日增重,促进瘤胃发酵,有利于提高肉牛生长性能。

Effects of Different Levels of Grape Seed Pomace on In Vitro Gas Production,Fermentation Parameters,Nutrients Digestibility and Growth Performance of Simmental Cattle

Objective] To investigate the effects of different levels of grape seed pomace （GSP） replacing partial corn and cottonseed meal in concentrate supplements on in vitro rumen gas production, in vitro nutrients digestibility, fermentation parameters, and growth performance of Simmental cattle. Method] Using the rumen simulation technique, corn and cottonseed meal in concentrate supplements were partially replaced by GSP at proportions of 4%, 8%, 12% and 16%, respectively. The in vitro gas production, fermentation parameters, in vitro nutrients digestibility of each groups were measured, and the growth performance of the cattle fed with diets in which corn and cottonseed meal were partially replaced by different levels of GSP were evaluated. Result] The cumulative gas production increased as the in vitro fermentation period extended. The 12% GSP group produced the most gas, and there was no significant （P>0.05） difference in total gas production across the different groups at 72 h of fermentation. There were no significant （P>0.05) differences in pH value, NH₃-N concentration, or bacterial protein content in the artificial rumen fluid between the different groups after gas production. The concentrations of volatile fatty acids increased significantly （P<0.05) in the experimental groups. The digestibility of dry matter was the lowest in the 16% GSP group. The digestibility of crude protein in the control group was significantly （P<0.05) higher than that in the experimental groups. The digestibility of neutral detergent fiber in the control group and the 4% GSP group was significantly （P<0.05) higher than that in the other three groups. The digestibility of acid detergent fiber in the control group and the 12% GSP group was significantly （P<0.05) higher than that in the other three groups. The average daily gain of the cattle in the 4% and the 8% GSP groups was 170 g/d and 140 g/d higher than that of the control group, respectively. Conclusion] Replacement of partial corn and cottonseed meal in concentrate supplements with GSP improved the concentrations of volatile fatty acids in artificial rumen fluid. Replacing proportions of 4% or 8% of GSP increased the daily gain and boosted the rumen fermentation of beef cattle, which was conducive to improve the growth performance.