不同放牧时间对滩羊血液生化指标和肌肉代谢的影响

Effect of Grazing Time of Tan Sheep to Desert Pasture on the Blood Indexes and Muscle Enzyme Activity

为探讨不同放牧时间滩羊血液生化指标和肌肉代谢的变化,选取4月龄体重相近（15.62±0.33）kg、体况状况良好的滩羊公羔50只,随机分为5个处理组,每个处理10只羊,每天分别放牧0（舍饲）、2、4、8、12 h,放牧时间为120 d。试验0、60 d和120d采血,试验结束后屠宰,取背最长肌和股肌样品。结果表明：不同的放牧时间主要影响血液中与能量代谢有关的葡萄糖和甘油三酯的含量,试验60 d时,放牧处理对血糖含量影响显著（P〈0.05）,试验120 d时,2 h和4 h组血糖和甘油三酯均显著高于0 h和12 h组（P〈0.05）。不同的放牧时间处理对滩羊背最长肌糖原、血红蛋白和IGF-1含量影响不显著。背最长肌中无氧酵解乳酸脱氢酶的活性不受放牧时间的影响,而股肌中乳酸脱氢酶则随放牧时间的增加有增加的趋势（P=0.08）草地放牧组滩羊（2、4、8 h和12 h）背最长肌和股肌的琥珀酸脱氢酶活性均比0 h组高（P〈0.05）放牧2 h和8 h组滩羊背最长肌苹果酸脱氢酶的活性显著比0 h组高（P〈0.05）。结果显示放牧时间影响血液中葡萄糖和脂肪的含量,提高了肌肉中有氧代谢酶的活性,

To investigate the effect of different access time to desert steppe on Tan sheep blood indexes and muscle enzyme activity. Fifty male Tan sheep, 4 months of age, with an original body weight of （15.62 ± 0.33） kg were selected. The animals were randomly allocated to five different restricted grazing time treatments of 0 h/d （drylot feeding）, 2, 4, 8 and 12 h/d on pasture for 4 months grazing. Tan sheep were blood during experiment （0, 60 d and 120 d, respectively）. The tan sheep were blood, slaughtered, and the longissimus dorsi and vastus muscles were sampled at the end of the experiment. The results showed that the different grazing time mainly affected the blood content of glucose and triglyceride （P〈0.05）. On d 60, the grazing treatment significantly affected the blood glucose （P〈0.05）. At the end of the experiments （on d 120 ）, the blood glucose and triglyceride levels of 2 h and 4 h group were significantly higher than that of 0 h and 12 h group （P〈0.05）. The longissimus dorsi lactic dehydrogenase activity was not influenced by restricted grazing access on grassland, while vastus lactic dehydrogenase activity had an increasing trend with increased grazing time （P = 0.08）. But the succinate dehydrogenase activity of longissimus dorsi and vastus of 0 h group Tan sheep were lower than those of other groups （P〈0.05）, and the malate dehydrogenase activity of longissimus dorsi of 2 h and 8 h group tan sheep were significantly higher than that of 0 h group （P〈0.05）. In conclusion, grazing time on desert pasture changed glucose and triglyceride levels of Tan sheep, and affected oxidative metabolic enzyme activity of muscle. The grazing time of 2 h to 8 h were best for tan sheep.