本研究旨在考察持续高温对不同性别北京油鸡脂肪代谢及血液脂肪细胞因子水平的影响.选择健康、体重相近的49日龄北京油鸡公母各72只[公鸡平均体重(608.58±13.07)g;母鸡平均体重(518.50±8.33)g],随机分在2个处理中:高温组,(35.00±0.37)℃;适温组,(25.00±0.38)℃,每个处理设6个重复,每个重复6只鸡.试验持续23 d.测定试验第12、23天时的血液生化指标、血液脂肪细胞因子水平及脂肪组织脂蛋白酯酶活性.结果表明:1)对公鸡而言:持续高温12 d时血清胰岛素水平显著升高(P＜0.01),血浆甘油三酯含量显著降低(P＜0.01).持续高温23 d时血清胰岛素水平和血浆甘油三酯含量显著降低(P＜0.01),血浆葡萄糖含量显著升高(P＜0.01);对母鸡而言:持续高温12 d时血浆甘油三酯、游离脂肪酸含量显著降低(P＜0.05).持续高温23 d时血浆甘油三酯、游离脂肪酸含量无显著变化(P＞0.05),血浆极低密度脂蛋白含量有增加趋势(P =0.065),血浆葡萄糖含量显著升高(P＜0.01).2)持续高温12 d时公母鸡的肌间脂肪脂蛋白酯酶活性都显著降低(P＜0.05),持续高温23 d时公鸡的肌间脂肪脂蛋白酯酶活性显著降低(P＜0.05),而母鸡的无显著变化(P＞0.05).3)公母鸡血浆脂联素、抵抗素水平在高温下都无显著变化(P＞0.05);持续高温12 d时公鸡血浆瘦素水平显著降低(P＜0.01),母鸡的显著升高(P＜0.05).由此可知,随着持续高温时间的延长,母鸡血浆游离脂肪酸、甘油三酯含量及肌间脂肪组织脂蛋白酯酶活性受高温影响下降程度减小,公鸡血浆甘油三酯含量及脂肪组织脂蛋白酯酶活性下降程度加大.%This study was conducted to investigate the effects of chronic heat exposure on lipid metabolism and adipocytokine levels in Beijing-You (BJY) chickens. One hundred and forty-four 49-day-old healthy BJY chickens (72 males and 72 females) with similar weight [male: (608. 58 ±13. 07) g; female: (518. 50 ± 8. 33) g] were randomly assigned to two treatments with 6 replicates in each treatment and 6 birds in each replicate: high-temperature group, (35. 00 ±0.37) ℃; optimal-temperature group, (25. 00 ±0.38) ℃. The experiment lasted for 23 days. The biochemical indices and adipocytokine levels in blood and lipoprotein (LPL) activity in adipose tissue of BJY chickens on 12 and 23 d were assayed. The results showed as follows: 1) for males, plasma insulin (INS) level was increased (P<0. 01) , and triglyceride (TG) content was decreased by heat exposure at l2d (P<0.01); plasma INS level and TG content were decreased (P <0. 01) , and glucose content was increased by heat exposure at 23 d (P <0. 01). For females, free fatty acids (FFA) and TG contents in plasma were decreased by heat exposure at 12 d (P <0. 05) ; plasma glucose content was increased ( P < 0.01) , and very low density lipoprotein (VLDL) content was increased (P = 0.065) , but TG and FFA contents were not affected by heat exposure at 23 d (P >0. 05). 2) The activity of LPL in intramuscular fat of male and female chickens was significantly decreased by heat exposure at 12 d (P <0. 05) ; heat exposure decreased LPL activity in intramuscular fat of male (P <0. 05) but not female (P >0. 05) at 23 d. 3) The levels of adiponectin ( ADP) and resistance (RES) in plasma of male and female chickens were not affected (P >0. 05) ; plasma leptin level of male chickens was markedly decreased (P <0. 01) , but that of female chickens was increased by heat exposure at 12 d (P <0. 05). These results suggest that with the prolonged exposure time, the decreasing degree of the contents of FFA and TG in plasma and the activity of LPL in adipose tissue of female chickens are relieved, but the content of TG in plasma and the activity of LPL in adipose tissue of male chickens are decreased more severely.
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