大豆黄酮对绍兴鸭产蛋性能影响及有关中枢机制初探

Effect of Daidzein on Laying Performance of Shaoxing Ducks and Its Central Mechanisms Involved

随机挑选415日龄绍兴鸭320羽, 分成对照组和试验组,持续9周在基础日粮中分别添加0和5 mg穔g-1大豆黄酮,记录产蛋率、蛋重和摄食量。放射免疫分析法测定血清E2水平,相对定量RT-PCR方法,测定下丘脑GH受体、IGF-1受体、GnRH及垂体GH受体、IGF-1受体、GH基因表达的变化。结果表明,试验组产蛋率提高7.70%(P<0.01),平均蛋重也有所增加 (P =0.058),料蛋比降低6.44%(P<0.01);血清E2水平显著提高(P<0.01)。下丘脑GH受体和IGF-1受体基因表达水平显著下降,而GnRH基因表达显著升高;垂体GH受体和IGF-1受体基因表达水平没有显著变化,但GH mRNA含量显著提高。提示大豆黄酮可以通过中枢途径调节下丘脑-垂体生长轴和生殖轴某些基因的表达,进而影响动物的繁殖功能。

Three hundred and twenty 415-d-old Shaoxing ducks were selected and randomly divided into control andtreatment and groups and fed basal diet with dietary supplementation of daidzein at 0 and 5 mg·kg-1 for 9 weeks, respectively.The laying performance was recorded and at the end of the experiment, the serum E2 level was analyzed by radioimmunoassay(RIA) and the relevant tissues were sampled to detect the expression of growth hormone receptor (GHR), type 1 insulin-likegrowth factor receptor (IGF-1R), GnRH genes in the hypothalamus and GHR, IGF-1R, GH genes in the pituitary by usingrelative quantitative RT-PCR. The egg production rate of ducks in daidzein supplemented group increased by 7.71% (P<0.01),and the mean egg weight also increased (P=0.058) considerably. Moreover, the feed efficiency improved by 6.44% (P<0.01).The serum E2 level increased significantly in the experimental group. Daidzein treatment significantly reduced the levels of GHRand IGF-1R mRNA in the hypothalamus, but not in the pituitary. Meanwhile, the levels of GnRH mRNA in hypothalamus andGH mRNA in the pituitary increased evidently. The results suggest that daidzein can regulate the expression of some genes in thehypothalamus and pituitary to promote laying performance of Shaoxing ducks.