日粮中添加米糠和玉米胚芽粕对泌乳奶牛瘤胃发酵及微生物菌群的影响

Effects of rice bran and corn germ meal on rumen fermentation and microbial flora in lactating dairy cows

为探究泌乳奶牛日粮中添加米糠和玉米胚芽粕对奶牛瘤胃发酵及微生物菌群的影响,选择24头健康荷斯坦奶牛,其胎次、产奶量和泌乳天数相近,将24头奶牛分为4组(完全随机区组),以NRC(2001)为参照依据,以奶牛基础日粮干物质为基础,对照组(CK组)不添加米糠和玉米胚芽粕,试验A、B、C组日粮中分别添加3.40%米糠和6.80%玉米胚芽粕、6.65%米糠和13.30%玉米胚芽粕、9.98%米糠和19.98%玉米胚芽粕。分别于07:30、14:30和20:30饲喂,试验期包括预饲期(14d)和正饲期(42d),试验期共56d。结果表明:不同处理间泌乳奶牛的瘤胃pH值、氨态氮、挥发性脂肪酸和微生物蛋白无显著差异;试验A组可提高黄色瘤胃球菌和溶纤维丁酸弧菌基因相对表达量,促进瘤胃中纤维降解菌和蛋白降解菌群,提高瘤胃对养分的吸收利用效率。

This experiment studied that the effects of rice bran and com germ meal on rumen fermentation and microbial flora in dairy cows.We chose 24 healthy Holstein cows,with similar parity,milk yield and lactation clays and divided them into 4 groups randomly.With the NRC(2001)as the reference,on the basis of dry matter of cows diet,control group added 0%com germ meal and 0%rice bmn(group GK),the experimental group was added with 3.40%rice bran and 6.80%corn germ meal(group A),6.65%rice bran and 13.30%com germ meal(group B),and 9.98%rice bran and 19.98%com germ meal(group C).Feeding was conducted at 07:30,14:30 and 20:30 respectively,and the experi-mental period included prefeeding period of 14 d and 42 d day positive feeding period,with a total of 56 d in the experimental period.The results showed that there was no significant effect on ruminal pH,NH3-N,MCP and VFA(P〉0.05).Group A,increased the relative gene expression of Ruminococcus flavefaciens and Butyrivibrio fibrisolvens y promoted the flora of fiber-degracling bacteria and protein-degracling bacteria in the rumen,and improved the absorption and utilization efficiency of nutrients.