饲养方式对苏尼特羊肠道菌群与脂肪酸代谢的影响

Effect of Feeding Pattern on Intestinal Flora and Fatty Acid Metabolism in Sunit Sheep

以12月龄不同饲养条件(放牧和放牧+舍饲)苏尼特羊背最长肌、粪便、血液为实验材料,利用高通量测序技术和气相色谱-质谱法分析不同饲养方式下苏尼特羊肠道微生物及其代谢物、血脂指标和肌肉中脂肪酸的组成和含量差异。结果表明:放牧+舍饲组中拟杆菌属,Alistipes和Phocaeicola的丰度显著高于放牧组(P<0.05),而纤维杆菌属和瘤胃球菌属的丰度显著低于放牧组(P<0.05)。放牧组中乙酸和丁酸含量显著低于放牧+舍饲组(P<0.05),丙酸含量显著高于放牧+舍饲组(P<0.05)。血液中甘油三酯和高密度脂蛋白胆固醇含量差异显著(P<0.05)。放牧组中α-亚麻酸、二十碳五烯酸、二十二碳六烯酸和共轭亚油酸含量显著高于放牧+舍饲组(P<0.05)。通过相关性分析可知,羊肉中α-亚麻酸和共轭亚油酸含量与纤维杆菌属、瘤胃球菌属和Alistipes丰度呈显著正相关(P<0.05),与拟杆菌属丰度呈显著负相关(P<0.05)。乙酸与亚麻酸含量呈显著负相关(P<0.05),而丙酸与羊肉中二十碳五烯酸和二十二碳六烯酸含量呈显著正相关(P<0.05)。放牧组羊肉具有较高的营养价值,并且改善肠道微生物可提高圈养羊肉品质。

The aim of this study was to investigate the effects of different feeding patterns(grazing alone and combined with barn feeding)on the fatty acid composition of longissimus dorsi,the abundance of intestinal flora,facel short chain fatty acid and plasma lipid parameters in Sunit sheep aged 12 months by high throughput sequencing and gas chromatography-mass spectrometry(GC-MS).The results showed that at the genus level,the abundance of Bacteroides,Alistipes,and Phocaeicola in the grazing plus bran feeding group was significantly higher,while the abundance of Fibrobacter and Ruminococcus was significantly lower than in the grazing group(P<0.05).The contents of fecal acetate and butyrate in the grazing group were significantly lower(P<0.05),whereas the content of fecal propionate was significantly higher than in the grazing plus barn feeding group(P<0.05).The plasma concentrations of triglyceride and high density lipoprotein cholesterol in the two groups were significantly different(P<0.05).The contents ofα-linolenic acid,eicosapntemacnioc acid(EPA),docosahexaenoic acid(DHA)and conjugated linoleic acid(CLA)in muscle from the grazing group were significantly higher than those in the grazing plus bran feeding group(P<0.05).Correlation analysis showed thatα-linolenic acid and CLA of longissimus dorsi muscle were positively correlated with the abundance of Fibrobacter,Ruminococcus and Alistipes(P<0.05)but negatively correlated with Bacteroides(P<0.05).Fecal acetic acid was negatively correlated withα-linolenic(P<0.05)while fecal propanoic acid content was positively correlated with EPA and DHA(P<0.05).This study concluded that meat from grazing sheep has better nutritional value and that the combination of grazing with barn feeding can change the intestinal flora of sheep to improve meat quality.