关键词: 肉种鸡, 产蛋周龄, 类固醇激素, 代谢差异, 液相色谱?串联质谱

Abstract: The purpose of this experiment was aimed to compare the follicular development and serum steroid metabolism in broiler breeders of different laying weeks. Six broiler breeders were randomly selected at the beginning of preinitiation（24 weeks of age），at the peak of laying（28 weeks of age），and at the late stage of laying（47 weeks of age）. Liquid chromatogram?tandem mass spectrometry（LC?MS/MS）was used to detect serum steroid hormone levels in broiler breeders at different laying weeks of age. The results showed that the number of small yellow follicles was significantly higher at the late stage than those detected at thepeak stage（P<0.01）. The progesterone concentration in the perinatal period was highest，and significantly higher than that in the peak of egg production（P<0.01）. The levelsof 11?deoxycortisol and testosterone were the highest at the peak of egg laying.Meanwhile，the content in the opening perinatal period was the second，and the content in the late laying period was the lowest. Progesterone and estradiol levels were the lowest in the peak laying period but increased in the late laying period. In the late laying period，the content of estradiol was significantly higher than that in the peak laying period（P<0.01），and the level of progesterone was significantly higher than that in the peak laying period（P<0.05）；The level of estradiol in late laying period was significantly higher than that in the opening period（P<0.05）. The content of 17 ? hydroxypregnenolone increased gradually with the increase of laying week age，but there was no significant difference between different weeks of age. Overall，our results indicated that the low reproductive performance of broiler breeders may be related to the retardation of the development of small yellow follicles recruited into the preovulatory hierarchy and the significant increase of estradiol and progesterone in serum.

Key words: Broiler, Laying age, Steroid hormone, Metabolic difference, Liquid chromatography?tandem mass spectrometry