Objective  Effects of exposure to artificial lights on estrus synchronization and hormone secretion in female rabbits were investigated in order to improve the reproductive performance of Minxinan black rabbit.

  Method  Non-breeding Minxinan black female rabbits at the age of 150 d were raised under LED and energy-saving lamps or natural light for one week. A daily exposure cycle of L:D=16:8 h on the treatment animals or of the natural light conditions for the control group was applied. Estrus occurrence rates of the rabbits on both groups were recorded 1 d before as well as 3 d and 7 d after the beginning of the treatment. At the same time, blood samples were collected from the ear vein of the rabbits for serum melatonin, follicle stimulating hormone, and estradiol determinations by ELISA.

  Result  (1) The artificial light exposure significantly increased estrus in the rabbits. (2) After 3 d and 7 d of the treatment, the serum melatonin in the rabbits decreased significantly, while the follicle stimulating hormone and estradiol increased slightly, whereas, no significant differences on those were detected in the control group.

  Conclusion  The artificial light exposure appeared to significantly affect the estrus of 150-d-old non-parous Minxinan black female rabbits. It also exerted a significant effect on the serum melatonin, but not on the follicle stimulating hormone or estradiol in the rabbits.