【摘要】 选用3头体况良好,3月龄左右,安装永久性瘤胃瘘管的荷斯坦公犊牛,采用3×3拉丁方试验设计,试验分3期。设计3种犊牛全混合日粮,精料补充料主要由玉米、麸皮、豆粕、玉米酒精糟和玉米胚芽粕等组成,粗料由苜蓿和羊草按照1∶1构成,试验Ⅰ组、试验Ⅱ组和试验Ⅲ组日粮的cNFC/cNDF比值分别是6.09、2.57和1.31。结果表明:各试验组日粮中干物质、粗蛋白质、NDF和ADF在瘤胃内的72h降解率均无显著差异(P>0.05),但低cNFC/cNDF日粮的降解率变化较平稳,同时,低cNFC/cNDF日粮组的pH平均值显著升高(P<0.05),NH3-N浓度平均值显著降低(P<0.05),VFA浓度无显著差异(P>0.05)。结果提示,适当降低犊牛日粮中cNFC/cNDF的比例有助于促进犊牛瘤胃发酵的稳定。更多还原

【Abstract】 Three healthy Holstein creep bull calves of 3-month-old with permanent rumen fistula were randomly allocated to 3 groups by 3×3 Latin square design.The experiment was divided into 3 periods.Three kinds of total mixed ration for calves were designed.The concentration part was composed with corn,wheat mill run,soybean meal,DDGS.The roughage originated from alfalfa and Chinese leymus with the ratio of 1∶1.The ratio of cNFC to cNDF in diets of group Ⅰ,Ⅱand Ⅲ were 6.09,2.57 and 1.31.The results showed that:the degradation rate of DM,CP,NDF and ADF among all treatments in 72 h had no significant difference(P > 0.05),but the degradation rate of lower cNFC/cNDF diet varied steady relatively.The average of pH was significantly increased,and the average of NH3-N concentration was significantly decreased in lower CNFC/CNDF diet.The concentration of VFA had no significantly difference in treatments(P > 0.05).The experiment was indicated that reducing the ration of cNFC/cNDF in calves diet could improve the stability of ruminal fermentation in calves.更多还原