Effects of heat stress on reproductive performance ,blood reproductive hormone concentrations and gene mRNA expression in different varieties of chicken | 热应激对不同品种鸡繁殖性能、血液生殖激素及相关基因mRNA表达量的影响

Chinese. 为探讨热应激对我国地方鸡种与国外培育蛋鸡品种繁殖性能、血液生殖激素及相关基因mRNA表达量的影响,试验选择体况相近的112日龄济宁百日鸡和海兰褐鸡各96只,随机分为适温组（（25±0.26）℃）和高温组（（38±0.26）℃）2个处理,在人工环境气候舱中饲养,每个处理各设8个重复,每个重复6只,试验持续28d。测定112、119、126和140日龄时的卵巢重量、卵泡总数和血液生殖激素浓度及生殖轴相关基因mRNA相对表达量。结果表明：1）适温条件下海兰褐鸡的卵巢、总卵泡发育好于济宁百日鸡,而热应激第7天济宁百日鸡和海兰褐鸡只出现明显的卵巢发育受阻、总卵泡数量增生缓慢（P〈0.05）。2）在整个热应激期高温组卵泡刺激素（FSH）和促黄体生成素（LH）含量显著下降（P〈0.05）,热应激7d后雌二醇（E2）含量显著减少（P〈0.05）、孕酮（P4）含量先升高后显著下降（P〈0.05）;促肾上腺皮质激素释放激素（CRH）含量显著高于适温组（P〈0.05）,济宁百日鸡高温组各血液生殖激素水平的变异系数高于海兰褐,且差异不显著（P〉0.05）。3）适温组的济宁百日鸡促性腺激素释放激素（GnRH）、催乳素（prolactin,PRL）、卵泡刺激素-β（FSH-β）、促卵泡素受体（LHR）、雌激素受体（ESR）、催乳素受体（PRLR）、卵泡刺激素受体（FSHR）的mRNA表达量均高于海兰褐鸡,但无显著差异（P〉0.05）;而高温组济宁百日鸡mRNA表达量除PRL以外,均显著高于海兰褐鸡（P〈0.05）。结果提示,地方品种在热应激环境条件下卵巢、总卵泡发育和各血液生殖轴相关激素的分泌调控机能强于外来品种;并且生殖轴相关激素mRNA表达量的变化具有品种效应。

English. This study is to explore the effects of thermal stress on reproductive performance, blood reproductive hormones and genes mRNA expression to the country local variety and foreign cultivate layers varieties. Test choice body condition similar 16 Ninety-six sixteen-week Jining Bairichicken and 96 Hy-line variety Brown chicken were random grouped into optimum temperature group （25 ± 0.26） ℃ and High temperature group （38 ± 0.26） ℃ testing for 28 days. Each group has eight repeats with 6 chicken in each repeat. Ovary weight, follicle total and blood reproductive hormone concentration and reproductive shaft related gene expression mRNA relative quantity were determination at 112,119,126,and 140 days of age. The results show that： 1） Ovarian and total foIJicular of the Hailan brown chickendeveloped better than which in Jining Bairi chicken under the optimum temperature conditions, however, Jining Bairi chicken and Hy-line variety Brown chicken appeared obvious ovarian development hindered, total follicle number hyperplasia slow （P〈0.05） at 7th days of the heat stress. 2） in the whole thermal stress period, high temperature group of follicle stimulating hormone （FSH） and luteinizing hormone （LH） hormone content significant change （P〈 0.05）, heat stress after 7d estradiol （E2） was significantly reduced （P〈0.05）, progesterone （P4） increased at first, then dropped significantly （P〈0.05） ; GRH level significantly higher than that of optimum temperature group （ P〈 0.05） ,reed jining one hundred days chicken high temperature group of each blood reproductive hormone level of the coefficient of variation of the Hy-line variety Brown, and no significant difference （P〉0.05）. 3） optimum temperature treatment group ol reed jining one hundred days chicken GnRh, PRL, FSH-β, ESR, LHR, FSHR mRNA expression quantity are Hy-line variety Brown chicken, but no significant difference（P〉0.05） ;and high temperature group reed Jining Bairi chicken mRNA expression quantity except outside PRL significantly Hy-line variety Brown chicken （P〈0.05）. The results indicate, local variety in thermal stress condition ovarian, total follicular development and the blood reproductive shaft relevant hormone secretion regulation function better than foreign varieties; And reproductive shaft relevant hormone mRNA expression quantity changes with various effect.