Variable Response to Hormonal Induction of Multiple Ovulation in Quail

Abstract

Studies were conducted to induce multiple ovulation in Japanese quail. Laying quail were injected with 20I.U./quail of PMSG once a day for 5 successive days followed by a single treatment with 50μg/quail of oLH about 24hr after the last PMSG injection. The hens were decapitated 8 to 9hr later. Other quail received only oLH or vehicle 12hr before the predicted time of ovulation. All quail in the vehicle-injected control group ovulated at the expected time. The injection of oLH resulted in premature oviposition and ovulation. Within the PMSG-primed and oLH injected group, 10 out of 19 quail were induced to ovulate single or several follicles (ovulation rate, 53%), whereas 9 quail failed to ovulate. Daily egg laying during PMSG administration was without relationship with rate of multiple ovulation. Most of the PMSG-primed and oLH injected quail had heavier ovaries with many yellow follicles arranged in non-hierarchical way in contrast to ovaries of control and only oLH-treated birds. The results showed very variable responses of quail to oLH treatment in the PMSG-primed birds. Our method is not recommendable for common use because of inefficiency of egg collection after low rate of multiple ovulation which requires expense and labour.