TMR饲养条件下奶牛瘤胃VFA、pH变化规律的研究

为探究全混合日粮(TMR)饲养条件下奶牛瘤胃发酵参数的变化规律,以3头装有永久性瘤胃瘘管的中国荷斯坦奶牛为试验动物,采用TMR饲养,测定了瘤胃24h挥发性脂肪酸(VFA)浓度及pH值。结果表明:在TMR条件下,试验奶牛瘤胃液pH值的变化范围为5.86～6.51,各时间点之间差异不显著(P>0.05);乙酸浓度、丙酸浓度、丁酸浓度变动范围分别为69.62～85.71mmol/L、19.33～25.91mmol/L、10.44～14.02mmol/L,且3种VFA出现最高浓度和最低浓度的时间点均为20:00和08:00;乙酸/丙酸值的变动范围为3.31～3.61,且在20:00比值最小,在8:00比值最大。综合分析显示,TMR技术有利于奶牛瘤胃丙酸型发酵,提高生产效益。

Study on the Rumen VFA and pH with the Time Changing in Cows under the Condition of TMR Feeding

A total of three China Hostain cow fitted with ruminal fistula were used to determine the vary law in 24 h of the ruminal intemal environment parameters under the Total Mixed Ration(TMR) technology.The results showed that the rumen pH value changed over time and the average pH was 5.86-6.51,but no significant changes were observed at each time point.The average concentration of acetic acid,third acid and butyric acid was 69.62-85.71 mmol/L,19.33-25.91 mmol/L and 10.44-14.02 mmol/L,respectively.The maximum and lowest concentrations of three VFA appeared at 20:00 and 08:00.The average of acetic acid/propionic acid varied from 3.31 to 3.61,with the minimum and maximum levels appearing at 20:00 and 8:00 respectively.Comprehensive analysis showed that the TMR technology was conductive to rumen propionic acid type fermentation to improve production efficiency of cow.