饲粮中添加莫能菌素对奶牛瘤胃发酵参数的影响

Effect of dietary monensin on the ruminal fermentation characteristics of lactating dairy cows

选取泌乳期奶牛12头,采用重复4×4拉丁方试验设计,对照组饲喂基础饲粮（A组）,试验组分别在基础饲粮的基础上添加300（B组）、400（C组）、500（D组）mg/（头·d）莫能菌素,探讨饲粮中添加不同水平的莫能菌素对奶牛瘤胃发酵相关参数的影响。结果表明,饲粮中添加莫能菌素可提高瘤胃液pH值,显著降低瘤胃液微生物蛋白（MCP）、总挥发性脂肪酸（T-VFA）、乙酸含量以及乙酸/丙酸的值,增加丙酸含量（P〈0.05）,对氨态氮（NH3-N）和丁酸没有显著性影响（P〉0.05）;C组较对照组T-VFA和乙酸的降低程度最大,分别降低了22.71%和28.59%（P〈0.05）;D组的MCP和乙酸/丙酸值较对照组降低程度最大,分别降低了33.99%和31.15%（P〈0.05;D组中丙酸的含量增加最多为9.63%（P〈0.05）。综上所述,奶牛饲喂400-500mg/（头·d）的莫能菌素更有利于促进瘤胃内丙酸型发酵。

To determine the effect of feeding different levels of monensin on the ruminal fermentation characteristics of lactating dairy cows,twelve lactating Holstein dairy cows were selected and randomly assigned into 4groups by balanced 4×4Latin square design.They were fed with four different diets.The control group was fed with the based diet（TMR,group A）,and the three experimental groups were added with different levels of monensin（300 mg/d,group B;400 mg/d,group C;500mg/d,group D）on the basis of the TMR diet,respectively.The results showed that the diets containing monensin increased the ruminal pH,and decreased the microbial protein（MCP）concentration,total volatile fatty acid（T-VFA）,acetic acid and the ratio of acetic acid/propionic acid.Adding dietary monensin also significantly increased the concentration of propionic acid（P〈0.05）.However,compared to the control,ruminal ammonia nitrogen concentration（NH_3-N）and butyric acid concentration were not significantly changed in experimental groups（P〈0.05）.Compared to the control group,T-VFA and acetic acid concentration of group C showed the maximum reduction by 22.71% and 28.59%,respectively（P〈0.05）;Group D showed the lowest MCP concentration and the ratio of acetic acid/propionic acid by 33.99%and 31.15%,respectively（P〈0.05）,and the highest concentration of propionic acid by 9.63%（P〈0.05）.The resultssuggested that supplementing 400-500mg/d monensin with diet per cow was optimal for ruminal fermentation.