去势公猪脱氢表雄酮的生理水平及其对脂质代谢的影响

Effects of dietary DHEA supplementation on serum DHEA level and lipid metabolism in barrows

研究去势公猪体内脱氢表雄酮（DHEA）及其硫酸盐（DHEA-S）随日龄增长的变化规律,以及外源添加DHEA对去势公猪DHEA与DHEA-S水平、血脂以及脂肪沉积的影响,通过测定杜×（长×大）三元杂交仔公猪、仔母猪（21日龄）及去势公猪（28~203日龄）血清DHEA、DHEA-S、血糖、总胆固醇和甘油三酯的生理水平。选用体重40 kg左右的杜×（长×大）三元杂交去势公猪45头,随机分成3组,分别在对照组、低剂量组和高剂量组的饲料中添加0、25和75 mg/kg DHEA,处理105 d。结果显示：21日龄仔公猪血清DHEA质量浓度为仔母猪的2.86倍,明显高于仔母猪（P〈0.001）;28~203日龄去势公猪血清DHEA质量浓度仅为21日龄仔公猪的5.37%~12.03%,皆明显降低（P〈0.001）,且呈U型变化;日粮中添加DHEA明显增加去势公猪血清DHEA浓度,显著降低血清胆固醇、甘油三酯浓度和脂肪沉积,而对体重及血清DHEA-S浓度影响不显著。猪血清DHEA生理水平变化以及添加DHEA对脂质代谢指标的影响,提示DHEA具有调节去势公猪脂质代谢的作用。

The present study aims to measure DHEA physiological changes,and check whether dietary DHEA supplementation can affect serum DHEA and lipid metabolism in barrows.In studyⅠ and Ⅱ,the blood samples of boars,gilts and barrows（28-203 day-old） were taken for analyzing serum DHEA and DHEA-S.In study Ⅲ,45 crossbred Duroc×Landrace×Yorkshire barrows weighing approximately 40 kg at the start of the trail（98 day-old） were allocated randomly into 3 groups with 15 barrows in each group.The barrows were fed with the diet supplemented with 0,25 and 75 mg/kg DHEA.The pigs were slaughtered after the 105-day trail.The results showed that serum DHEA levels in boars were significantly higher than which of the gilts.After boars were castrated,the serum DHEA concentration was significantly lower（P〈0.001）,and showed a U-shaped pattern.Dietary DHEA significantly increased serum DHEA concentrations,but reduced serum cholesterol and triglyceride levels,while the concentration of serum DHEA-S had no significant effect.Backfat thickness and the index of the perirenal,mesenteric were reduced,whereas the body weight was unaffected.The physiological changes of DHEA and effects of DHEA treatment on lipid indices,suggest that the steroid may be involved in the modulation of lipid metabolism in barrows.