运动对苏尼特羊脂肪代谢和肉品质的影响

为探究运动对苏尼特羊脂肪代谢和肉品质的影响，选择体况良好、体质量为（20.22±0.68）kg的3 月龄苏尼特羊共12 只，随机分为对照组和运动组，对照组在半开放羊舍中圈养，运动组则在相同环境下每天进行约6 km的驱赶运动，预实验期7 d，正式实验期90 d。屠宰前称量羊活体质量，屠宰后取其背最长肌，利用气相色谱-质谱联用技术、实时荧光定量聚合酶链式反应等方法对羊肉品质指标、脂肪酸组成和脂肪代谢相关调控基因相对表达量进行测定。结果表明，运动组屠宰性能（活体质量、背膘厚度）和肉品质（肌内脂肪含量、L*值、a*值、b*值）均显著低于对照组（P＜0.05），且嫩度变差。运动组饱和脂肪酸相对含量略低于对照组，而n-3系列多不饱和脂肪酸含量则显著低于对照组（P＜0.05）。与对照组相比，运动组背最长肌中激素敏感性脂肪酶、脂肪酸合成酶、锌指蛋白PRDM16、解偶联蛋白-1的基因相对表达量均显著升高（P＜0.05）。综上，持续90 d的运动提高了苏尼特羊肉的脂肪代谢水平，但羊肉品质有所降低。

Effect of Exercise on Lipid Metabolism and Meat Quality of Sunit Sheep

In order to explore the effect of exercise on the lipid metabolism and meat quality of Sunit sheep, a total of 12 (3-month-old) Sunit sheep with good body condition and body mass of (20.22 ± 0.68) kg were selected and randomly divided into a control group and an exercise group. The animals in the control group were housed in semi-open pens, while those in the exercise group were subjected to exercise by driving about 6 kilometers every day under the same housing environment. The pre-experiment lasted for 7 days and the formal experiment lasted for 90 days. The body mass was measured before slaughter, and Longissimus dorsi muscle was harvested after slaughter for determining meat quality attributes, fatty acid composition and the expression of genes associated with lipid metabolism by gas chromatography-mass spectrometry (GC-MS), and real-time fluorescent quantitative polymerase chain reaction (PCR). The results showed that the slaughter performance (live body mass and back fat thickness) and meat quality (intramuscular fat content, pH, and the color parameters L*, a* and b* values) of the exercise group were significantly lower than those of the control group (P < 0.05) and the meat tenderness was worse than that of the control group. The relative content of saturated fatty acids in lamb meat from the exercise group was slightly lower than that in the control group, while the relative content of n-3 unsaturated fatty acids was significantly lower than that in the control group (P < 0.05). Compared with the control group, the relative expression levels of the hormone-sensitive triglyceride lipase (HSL), fatty acid synthetase (FASN), zinc finger protein PRDM16 (positive regulatory domain containing 16, PRDM16), and uncoupling protein1 (UCP-1) genes in the exercise group were significantly up-regulated (P < 0.05). In general, exercise for 90 days can improve the lipid metabolism of Sunit sheep, but decrease the meat quality.