诱导换羽过程中光照程序对蛋鸡卵巢功能重塑的辅助作用OA北大核心CSTPCD

Poultry is one of the animals that needs long time light exposure.Scientific and correct light program has a significant impact on the growth and development,sexual maturity,first birth age,and egg production peak of laying hens.It is of great production significance to set the corresponding light program during the different stages of induced molting in fasting and feeding recovery.In this study,529-day-old Guifei chickens with similar body weight and about 60％egg production rate were used as experimental material.According to the different periods of fasting induced moult,the changes of light regime were di-vided into four stages,and samples were collected at five different periods:the last day of the first stage(16 h L/8 h D,Before fasting),stage Ⅱ(8 h L/16 h D for 3 days),and stage Ⅲ(10 h L/14 h D for 13 days)(F0,F3,F16),and 6 d and 32 d of stage Ⅳ(gradually increasing light exposure by 0.5 h/d to 16 h L/8 h D).The number of follicles,ovarian antioxidant indicators,KIT-PI3K-PTEN-AKT signaling path-way and GDF9 gene expression were measured to explore the role of light program in the process of fast-ing induced molt.Results showed that the levels of FSH,LH,E2 and P4 in serum decreased when light ex-posure was shortened(P＜0.001),and the activities of superoxide dismutase(SOD)(P＜0.05)and gluta-thione peroxidase(GSH-PO)(P＜0.001)increased.In particular,primordial follicles were likely to be ac-tivated,leading to the increase of numbers of small yellow follicles(P＜0.01),primary follicles and sec-ondary follicles(P＞0.05).When the light was gradually restored,the expression of KIT and PI3K was continuously high(P＜0.001),the expression of PTEN decreased(P＜0.01),and the expression of AKT was basically unchanged(P＞0.05).The serum levels of reproductive hormones and ovarian antioxidant levels returned to the pre-test state,but the overall number of follicles increased.The results suggest that scientific and reasonable light program during fasting and molting has an auxiliary effect on the remodeling of ovarian function.