乳酸菌对苏尼特羊生长性能、肉品质及肠道微生物的影响

Effect of Lactobacillus on growth performance,meat quality and gut microbiota in Sunit sheep

【目的】旨在探究乳酸菌对苏尼特羊生长性能、屠宰性能、肉品质及肠道微生物的影响。【方法】选取12只体重相近的3月龄苏尼特羊,将其平均分为对照组(基础日粮)和试验组(基础日粮添加乳酸菌),公母各半,饲喂90 d后屠宰,期间测定了第30、60和90天的生长性能以及90 d屠宰后的屠宰性能、背最长肌肉品质。同时于第0、30、60和90天采集新鲜粪便进行高通量测序,分析乳酸菌对苏尼特羊肠道微生物的多样性以及肠道微生物菌群组成的影响。【结果】与对照组相比,试验组第30和90天的总增重和平均日增重均显著提高(P<0.05),且屠宰后的骨肉比与眼肌面积和pH_(24)显著高于对照组(P<0.05),蒸煮损失极显著低于对照组(P<0.01),其他性能和肉品质指标在对照组和试验组之间无显著差异(P>0.05)。饲喂乳酸菌后,苏尼特羊肠道微生物的多样性显著增加,Chao1和Ace指数显著高于对照组(P<0.05)。在门水平上,苏尼特羊肠道微生物的主要菌门是厚壁菌门和拟杆菌门,试验组第30和第90天厚壁菌门的丰度值显著高于对照组(P<0.05),而变形菌门丰度值显著低于对照组(P<0.05)。在属水平上,试验组饲喂第30天,瘤胃菌科_UCG-010、未分类毛螺菌属、另枝菌属的丰度值均显著高于对照组(P<0.05),而琥珀酸弧菌属的丰度值显著低于对照组(P<0.05)。试验组第60天,瘤胃菌科_UCG-010、未分类毛螺菌属、普雷沃氏菌属_1的丰度值显著高于对照组。试验组第90天,另枝菌属、普雷沃氏菌属_1、密螺旋体属_2的丰度值显著高于对照组(P<0.05),而琥珀酸弧菌属丰度值显著低于对照组(P<0.05)。【结论】乳酸菌作为天然绿色的抗生素替代品,其对提升苏尼特羊生长性能、屠宰性能、肉品质和改善肠道微生物组成均有积极影响,为乳酸菌饲料开发和改善舍饲羊生产性能提供理论参考。

【Objective】This experiment was conducted to investigate the effects of compound lactic acid bacteria on growth performance,slaughter performance,meat quality and intestinal microflora of Sunit sheep.【Method】Twelve 3-month-old Sunit sheep with similar body weight were randomly divided into control group(basal diet)and experimental group(basal diet supplemented with compound lactic acid bacteria),with half male and half female,and slaughtered after feeding for 90 days.The growth performance,slaughter performance and longest back muscle quality of Sunit sheep at the 30th,60thand 90thday were measured.Meanwhile,fresh feces were collected at the 0th,30th,60thand 90thday for high-throughput sequencing to analyze the effects of compound lactic acid bacteria on intestinal microbial diversity and composition of intestinal microflora of Sunit sheep.【Result】Compared with the control group,the total gain and average daily gain of experimental group at the 30thand 90ththe day were significantly increased(P<0.05),the ratio of bone to meat,loin eye area and pH_(24)after slaughter were significantly higher than those in the control group(P<0.05),and the cooking loss was extremely significantly lower than that in the control group(P<0.01).There were no significant differences in other performance and meat quality indexes between control group and experimental group(P>0.05).The Chao1 and Ace in the experimental group was higher than in the control group(P<0.05),which showed that feeding lactobacillus was beneficial for improving the diversity of gut microbiota.At the phylum level,gut microbiota of Sunit sheep mainly included Firmicutes and Bacteroidetes in two feeding methods.In the 30thand 90thday,the abundance of Firmicutes in the experimental group was higher than control group(P<0.05),and the abundance of Proteobacteria was significantly lower than control group(P<0.05).At the genus level,the abundance of Ruminococcaceae_UCG_010,unclassified_f__Lachnospiraceae,and Alistipes in the experimental group was higher than control group in the 30thday.However,the abundance of Succinivibrio in the experimental group was lower than in the control group(P<0.05).Compared to control group,the abundance of Ruminococcaceae_UCG_010,unclassified_f__Lachnospiraceae,and Prevotella_2 in the 60thday and the abundance of Alistipes,Prevotella_1 and Treponema_2 in the 90thday increased significantly in the experimental group(P<0.05),while the abundance of Succinivibrio decreased(P<0.05).【Conclusion】In conclusion,lactic acid bacteria,as a natural and green substitute for antibiotics,has a positive impact on improving growth performance,slaughter performance,intestinal microbial composition and meat quality of Sunit sheep,providing theoretical reference for the development of lactic acid bacteria feed and improving the performance of house feeding sheep.