番鸭等级前卵泡发育规律及生殖激素变化的研究

Changes of Reproductive Hormone and Follicle Development of Prehierarchical Follicles in Muscovy Duck

为探索番鸭等级前卵泡发育过程中主要生殖激素及卵泡发育的变化规律,试验以同批孵化、饲养条件相同、体况相近的产蛋期番鸭为对象,分别采集小白卵泡(SWF)、大白卵泡(LWF)、小黄卵泡(SYF)、大黄卵泡(LYF)。通过组织形态学方法观测卵泡的发育情况,酶联免疫吸附试验(ELISA)测定激素水平。结果表明:在等级前卵泡发育过程中,促卵泡素(FSH)和促黄体素(LH)呈现上升的趋势,且LYF时期浓度最高,差异不显著(P<0.05);而孕酮(P4)和雌二醇(E2)均呈现下降趋势,从SWF至SYF时期极显著下降(P<0.01),SYF至LYF时期,下降不显著(P>0.05)。伴随卵泡的发育,颗粒细胞层和卵泡膜层不断增厚,且卵泡膜厚度在LWF至LYF时期增长极显著(P<0.01)。由此可见,FSH、LH、P4、E2在番鸭等级前卵泡发育中起重要作用,且SYF阶段是番鸭等级前卵泡发育的关键阶段。

The laying Muscovy duck with the same batch incubation, rearing conditions and body condition were chosen as the experiment object to explore the changes of the main reproductive hormones and follicle development during the development of prehierarchical follicles. The small white follicles（SWF）, large white follicles（LWF）, small yellow follicles（SYF） and large yellow follicles（LYF） were collected for this experiment. The development of follicles was observed by histomorphometry and hormone levels of prehierarchical follicles were detected by enzyme-linked immunosorbent assay（ELISA）. The results indicated that follicle-stimulating hormone（FSH） and luteinizing hormone（LH） showed an upward trend during the process of prehierarchical follicles development. Both FSH and LH had the highest concentrations during LYF and had no significant difference（P〈0.05）. However, both progesterone（P4） and estradiol（E2） showed a decreasing trend, which was significantly decreased from SWF to SYF（P〈0.01）. There was no significant decrease from SYF to LYF（P〉0.05）. With the development of follicles, the granulosa cell layer and the follicular membrane layer were also continuously thickened; the thickness of the follicular membrane was significantly increased from LWF to LYF（P〈0.01）. Therefore, FSH, LH, P4 and E2 played important roles in the development of prehierarchical follicles,and SYF was a key stage in the development of prehierarchical follicles in Muscovy duck.