不同营养水平对湖羊黄体期血液理化指标及卵泡发育的影响

【目的】研究不同营养水平对湖羊黄体期血液理化指标及卵泡发育的影响。【方法】选择28只经产母羊，于发情周期第6天分别按0.5倍体重维持需要量（R组），1倍体重维持需要量（C组）和1.5倍体重维持需要量（S组）饲喂6 d，第12天每组屠宰6头；剩下的湖羊用于观察发情；分别于发情周期第7、8、10和12天采血。【结果】随着营养水平的提高，≥3.5 mm的卵泡数量显著增加（P＜0.05）、2.5-3.5 mm的卵泡数量显著降低（P＜0.05），平均发情周期缩短（P＜0.05），血液尿素、胆固醇和游离脂肪酸含量显著下降（P＜0.05），甘油三酯含量显著提高（P＜0.05）；S组乳酸脱氢酶活性显著高于C组（P＜0.05）；血液尿酸、血氨、高密度脂蛋白、低密度脂蛋白浓度和谷草转氨酶和谷丙转氨酶活性差异不显著（P＞0.05），但尿酸、血氨、低密度脂蛋白含量和谷草转氨酶活性具有时间效应（P＜0.05）。【结论】绵羊黄体期不同生理阶段具有不同的营养需求和代谢特点，黄体期限饲抑制卵泡发育与蛋白质和脂类合成降低、分解增强有关。

Effects of Different Levels of Diet on Plasma Physiochemical Indexes and Folliculogenesis in Hu Sheep During the Luteal Phase

【Objective】 The present study was designed to investigate the effects of different plasma physiochemical indexes on folliculogenesis in Hu sheep fed with different levels of diet during the luteal phase.【Method】Twenty-eight multiparous Hu sheep were assigned into 3 groups and received a maintenance diet(C group),0.5×M(R group) and 1.5×M(S group),respectively,for 6 days of their estrous cycle.Six ewes in each group were laughtered on day 12 of the estrous cycle.The remaining ewes were received a maintenance diet until the next estrus.Blood was sampled on days 7,8,10 and 12 of the estrous cycle.【Result】As dietary intake increased,the number of follicles of ≥3.5 mm was significantly increased(P<0.05),the number of follicles of 2.5-3.5 mm was significantly decreased(P<0.05) and the estrous cycle was shortened(P<0.05).Compared with R group,S group significantly decreased the plasma urea,total cholesterol,free fatty acid concentrations(P<0.05) and significantly increased the plasma triglyceride concentration(P<0.05).The activity of lactate dehydrogenase in S group was higher than C group(P<0.05).There was no significant effect of treatment on plasma uric acid,plasma ammonia,high density lipoprotein and low density lipoprotein concentrations and spartate transaminase,alanine transaminase activities(P>0.05),however,there was a significant effect of day on plasma uric acid,ammonia,low density lipoprotein concentrations and aspartate transaminase activity(P<0.05).【Conclusion】 Different nutritional requirements and metabolic features were present in different physiological periods during ovine luteal phase and the mechanism by which dietary restriction inhibited folliculogenesis may involve responses to the increased capacity of lipolysis and protein degradation and the decreased capacity of lipid and protein synthesis.