不同水平的青贮饲料对饲喂稻草秸秆奶牛瘤胃微生物数量和微生物蛋白合成的影响

Effects of different levels silage feed on rumen microbial quantity and microbial protein synthesis in dairy cows fed rice straw

本试验的目的是确定饲粮中青贮银合欢添加水平对奶牛瘤胃微生物种群、氮平衡和微生物蛋白合成的影响。试验采用4×4拉丁方设计,选择12头初始体重为163±16 kg、带有瘤胃瘘管的奶牛,随机分为4个组,每组3个重复,每个重复1头牛。基础日粮以100%的水稻秸秆为原料,处理组分别用30%、60%和100%的青贮银合欢替代水稻秸秆,奶牛自由采食水稻秸秆和青贮银合欢,每天按照体重的0.2%补充浓缩料。结果表明,用60%青贮银合欢替代水稻秸秆组奶牛瘤胃微生物群,尤其是纤维素分解菌、蛋白分解菌和厌氧真菌的数量显著增加(P<0.05),各组对淀粉分解菌群无显著影响(P>0.05)。原生动物种群数量随日粮青贮银合欢添加水平的增加呈线性下降(P<0.05)(P<0.05)。此外,氮平衡和微生物蛋白合成均随着日粮青贮银合欢添加水平的升高而升高(P<0.05),其中以60%青贮银合欢组最高。结论:在本试验基础上,用60%青贮银合欢替代水稻秸秆可以显著提高奶牛体内的微生物数量和微生物蛋白的合成。

The aim of this study was to determine the effects of dietary leucaena silage on rumen microbial population,nitrogen balance and microbial protein synthesis in dairy cows.A total of 12 cows with initial weight of 163±16 kg and rumen fistulas were randomly divided into 4 groups with 3 repeats in each group and 1 cow in each repeat.The basic diet used 100%rice straw as raw material,and the treated groups used 30%,60%and 100%leucaena silage to replace the rice straw,and the cows were free to eat rice straw and leucaena silage,and supplemented with 0.2%of their body weight of concentrate feed every day.The results showed that the number of rumen microflora,especially the number of cellulose decomposing bacteria,protein decomposing bacteria and anaerobic fungi in the 60%leucaena silage group,was significantly increased(P<0.05),and there was no significant effect on the starch decomposing bacteria in each group(P>0.05.).The protozoan population decreased linearly with the increase of dietary leucaena silage levels(P<0.05).In addition,nitrogen balance and microbial protein synthesis were increased with the increasing of levels leucaena silage(P<0.05),among which 60%leucaena silage group was the highest.In conclusion,based on the results of this experiment,60%leucaena silage can significantly increase the microbial quantity and microbial protein synthesis in cows.