Effect of Adding Lactic Acid Bacteria in Diet on Lipid Metabolism and Meat Quality of Sunit Sheep(日粮添加乳酸菌对苏尼特羊脂质代谢及肉品质的影响)
摘要
In order to investigate the effect of adding lactic acid bacteria (LAB) in the diet on lipid metabolism and meat quality of Sunit sheep, twelve Sunit sheep aged 3 months with good body condition [body weight (18.70±2.69)kg] were selected, and then randomly divided into two groups with six sheep each. The control group was fed a basic diet, and the LAB group was supplemented with compound LAB at 1.5×10<sup>9</sup>CFU/g based on the diet of the control group. The feeding period lasted for 90d. Meat quality, blood lipid indexes, fatty acid composition and the expression of lipid metabolism genes were measured after slaughter. The results showed that compared with the control group, the addition of LAB significantly increased the content of intramuscular fat and the value of pH in 24h (P<0.05), while significantly reduced L* and cooking loss (P<0.05) of longissimus dorsi muscle. The analysis of serum lipid metabolism showed that the dietary supplementation with the LAB decreased the low-density lipoprotein cholesterol and triglyceride of Sunit sheep (P<0.05). The contents of γ-linolenic acid, eicosatrienoic acid, arachidonic acid, eicosapentaenoic acid and eicosatetraenoic acid in the LAB group were significantly higher than the control group (P<0.05). Dietary supplementation of LAB could affect lipid-related indexes and fatty acid composition of Sunit sheep. Furthermore, the addition of LAB to the diet significantly inhibited the expression of AMP-activated protein kinase α2 gene in the longissimus dorsi muscle of Sunit sheep (P<0.05), and promoted the expression of acetyl-coa carboxylase, peroxisome proliferator-activated receptor γ and sterol regulatory element binding protein-1C (P<0.05). Therefore, dietary supplementation of LAB could regulate lipid metabolism in Sunit sheep through inhibiting AMP-activated protein kinase α2-acetyl-coa carboxylase signaling pathway.(为探究日粮添加乳酸菌对苏尼特羊脂质代谢和肉品质的影响,选取12只3月龄苏尼特羊[体重(18.70±2.69)kg],随机均分为对照组(基础饲粮)和乳酸菌组(基础饲粮添加复合乳酸菌,复合乳酸菌活菌数为