不同淀粉来源饲粮中添加酵母培养物对育肥湖羊生长性能、养分消化率及瘤胃发酵参数的影响

Effects of Yeast Culture Supplementation in Diets with Different Starch Sources on Growing Performance,Nutrient Digestibility and Ruminal Fermentation Parameters in Hu Sheep

本试验旨在研究不同淀粉来源(SS)饲粮中添加酵母培养物(YC)对育肥湖羊生长性能、屠宰性能、养分消化及瘤胃发酵参数的影响。采用2×2因子试验设计,选取体重约为(21.69±2.49) kg的2月龄湖羊公羔120只,随机分为4组,分别为添加1%YC的大麦淀粉(BS-1)组、大麦淀粉(BS)组、添加1%YC的玉米淀粉(CS-1)组、玉米淀粉(CS)组,每组5个重复,每个重复6只羊。预试期7 d,正试期56 d。结果表明:1)各组末重、平均日增重、干物质采食量和料重比均差异不显著(P>0.05)。2)各组宰前活重、胴体重、屠宰率、背膘厚度、GR值、尾脂重及肾周脂重均无显著差异(P>0.05),但BS-1组、CS-1组眼肌面积显著高于BS组、CS组(P<0.05)。3)各组干物质、有机物表观消化率无显著差异(P>0.05),但BS-1组、CS-1组中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)表观消化率显著高于BS组、CS组(P<0.05); 4)各组总挥发性脂肪酸含量及丙酸、丁酸、戊酸、异丁酸、异戊酸占总挥发性脂肪酸比例无显著差异(P>0.05),而BS组乙酸占总挥发性脂肪酸比例显著高于CS组(P<0.05)。综上,不同SS来源饲粮中添加YC未改变瘤胃发酵类型,但显著提高饲粮NDF与ADF表观消化率,进而提高育肥湖羊对粗饲料的利用率。

The objective of this experiment was to study the effects of yeast culture(YC)supplementation in diets with different starch sources on growth performance,slaughter performance,nutrient digestion and ruminal fermentation parameters of Hu sheep.The experiment adopted a 2×2 factorial arrangement.A total of 120 two-month-old healthy Hu sheep[(21.69±2.49)kg]were assigned to four groups:the barley starch supplemented with 1%YC(BS-1)group,the barley starch(BS)group,the corn starch supplemented with 1%YC(CS-1)group and the corn starch(CS)group,with five replicates in each group and 6 sheep in each replicates.The preliminary test period was 7 d and the formal trial period was 56 d.The results showed as follows:1)there were no significant differences in final weight,average daily gain,dry matter intake and the ratio of feed to gain among groups(P >0.05).2)There were no significant differences in live weight before slaughter,carcass weight,dressing percentage,back-fat thickness,GR value,tail fat weight and perirenal fat weight among groups(P >0.05),but the eye muscle area of groups BS-1 and CS-1 were significantly higher than those in groups BS and CS(P<0.05).3)The apparent digestibility of dry matter and organic matter in groups were no significant difference(P >0.05),but the apparent digestibility of neutral detergent fiber(NDF)and acid detergent fiber(ADF)in groups BS-1 and CS-1 were significantly higher than those in groups BS and CS(P<0.05).4)There were no significant differences in total volatile fatty acid(TVFA)content,the ratios of acetic acid,propionic acid,butyric acid,valeric acid,isobutyric acid,isovaleric acid to TVFA and the ratio of acetic to propionic among groups(P >0.05),but the ratio of acetate to TVFA in group BS was significantly higher than that in group CS(P<0.05).In summary,YC supplementation in diets with different starch sources does not change ruminal fermentation pattern,but significantly increase the apparent digestibility of NDF and ADF,thereby increasing the utilization of roughage.