肉牛日粮中添加活性干酵母对瘤胃蛋白降解及利用的影响  

Effect of Active Dry Yeast on Degradation and Utilization of Rumen Protein in Beef Cattle

作　　者：梁稼烨 昝林森[1,2] LIANG Jia-ye;ZAN Lin-sen(College of Animal Science and Technology,Northwest A ＆ F University,Yangling,Shaanxi 712100,China;National Beef Cattle Improvement Center,Yangling,Shaanxi,712100;China)

机构地区：[1]西北农林科技大学动物科技学院,陕西杨凌712100 [2]国家肉牛改良中心,陕西杨凌712100

出　　处：《中国牛业科学》2018年第4期9-13,共5页China Cattle Science

基　　金：国家重点研发计划(2018YFD0501700);国家肉牛牦牛产业技术体系(CARS-37)

摘　　要：本试验旨在研究饲料添加活性干酵母对秦川牛肉用新品系(以下简称"秦川肉牛")饲料蛋白降解和瘤胃氨态氮、菌体蛋白的影响。试验以3头装有永久性瘤胃瘘管的秦川肉牛为试验动物,饲喂相同的基础日粮,试验共分三期,每期30天,每期三头牛分别采用三种酵母添加水平(0、30、60g/d),间隔5d调整期。采用尼龙袋法分别测定四种饲料(苜蓿干草、豆粕、菜粕、棉粕)的粗蛋白(CP)在瘤胃内动态降解率的变化及测定瘤胃内氨态氮浓度、菌体蛋白浓度和挥发性脂肪酸发酵参数。结果表明:活性干酵母的添加对7种饲料的CP降解速率有不同程度的提高;活性干酵母具有降低氨态氮浓度(P<0.05),增加总挥发性脂肪酸的浓度(P<0.05),提高菌体蛋白浓度(P<0.05)的作用。综上,添加活性干酵母可显著提高秦川肉牛饲料CP的降解速率,不同饲料的降解率变化水平与其特性有关;而且具有降低瘤胃氨态氮浓度、提高总挥发酸浓度和菌体蛋白浓度,提高饲料中瘤胃降解蛋白的利用率的作用。（Objective）The aim of the study was to research the effects of adding active dry yeast to diet on the feed protein degradation,rumen ammonia nitrogen and microbial protein of Qinchuan cattle.（Method）Three Qinchuan cattle with permanent rumen fistula were used as experimental animal,and fed with the same basal diet.The experiment consisted of three periods.In each period,three cattle were treated with three yeast supplementation levels（0,30,60 g/d）,and lasted 30 days then separated 5 days for adjustment.Nylon bag method were used to determine changes of dynamic degradation rate of CP of four kinds of roughage（alfalfa,bean pulp,rapeseed meal,and cottonseed meal）in the rumen.Meanwhile,the fermentation parameters such as rumen pH,ammonia nitrogen concentration and volatile fatty acids were also detected.（Result）The addition of active dry yeast increased the degradation rate of CP in 7 feeds with varying degrees.Active dry yeast had reduced the concentration of ammonia nitrogen（P〈0.05）,increased the concentration of total volatile fatty acids（P〈0.05）and increased the concentration of microbial protein（P〈0.05）.（Conclusion）In conclusion,adding active dry yeast can significantly improve the degradation rate of DM,NDF and CP in beef cattle feed,and the level of degradation of different feeds is related to its characteristics.Moreover,it had the effects of reducing rumen ammonia nitrogen concentration,increasing total volatile acid concentration and bacterial protein concentration,and improving the utilization rate of rumen-degrading protein in feed.

关 键 词：活性干酵母 秦川肉牛 饲料蛋白 

分 类 号：S823[农业科学—畜牧学]