全混合颗粒日粮中添加乳糖对育成母羊生长性能及瘤胃发酵的影响

Effects of Lactose Supplementation in Total Mixed Pellet Diet on the Growth Performance and Rumen Fermentation in Growing Ewes

为研究在全混合日粮中添加乳糖对育成母羊生长性能及瘤胃发酵的影响,选取健康、体况良好、体重和出生日期相近的育成小尾寒羊母羊20只,随机分为2组,每组10只,分别为对照组和试验组。对照组饲喂基础日粮,试验组在基础日粮中用1%的乳糖取代1%的玉米。试验期64 d,其中预饲期14 d,正试期50 d。结果显示,乳糖组母羊的平均日增重和净增重均显著高于对照组(P<0.05),但2组间的平均日采食量差异不显著(P>0.05)。对照组和乳糖组母羊的瘤胃pH值间差异不显著(P>0.05);与对照组相比,乳糖组的瘤胃液氨氮浓度显著降低(P<0.05),乙酸、丙酸、丁酸和总挥发性脂肪酸的浓度显著提高(P<0.05);两组之间的异丁酸、戊酸、异戊酸浓度以及乙酸/丙酸均差异不显著(P>0.05)。

The objectives of this study were to investigate the effects of lactose supplementation in total mixed pellet diet on the growth performance and rumen fermentation in growing ewes.Twenty healthy female Small-tailed Han sheep with similar body weight and birth date were randomly divided into the control group and the experimental group,with 10 ewes in each group.Ewes in the control group were fed a basal diet,and those in the experimental group were fed a basal diet with 1%lactose in substitution of same amount of corn.The experiment lasted for 64 days,including 14 days of adaptation period and 50 days of sampling period.The results showed that compare to the control group,lactose supplementation in the total mixed diet significantly increased the average daily gain and net gain of ewes(P<0.05),but there was no significant difference in the average daily feed intake between the two groups(P>0.05).For the rumen fermentation,there was no significant difference in rumen pH between animals in the two groups(P>0.05).Lactose supplementation significantly decreased rumen concentration of ammonia nitrogen(NH3-N)(P<0.05),and significantly increased rumen concentrations of acetic acid,propionic acid,butyric acid and total volatile fatty acid(P<0.05).There were no significant differences in rumen concentrations of isobutyric acid,valeric acid,isovaleric acid and the ratio of acetic to propionic acids between the two groups(P>0.05).