مشخصات پژوهش

An experiment was conducted to study the effect of Epinephrine (EP) and bromocriptine (BR) on produc-tive traits of laying hens. Thirty White Leghorn hens, 50 weeks old, were divided into three equal treat-ments (with 10 hens for each treatment): control, physiological serum (0.5 mL/hen/week), EP (0.5 mL/hen/week) and BR (100 g/kg of body weight (BW); w/v in absolute alcohol). Hens were injected once a week for 10 weeks. At the end of the experimental period, all hens were killed by decapitation. Ovaries, oviducts and ovarian follicles were examined. Ovary folliculogenesis was affected (P<0.01) by EP and BR treatments. There were larger yellow follicle (LYF), smaller yellow follicle (SYF) and larger white follicle in EP and BR treated hens compared to control group respectively. EP and BR treatments shortened total pause length compared to control (P<0.01). Mean weekly egg production was higher (P<0.01) for treated hens with BR and EP compared to control group. Percentage of weekly egg production was higher (P<0.01) in treated birds compared to control group. It can be concluded that EP and BR may promote ovarian fol-licular development and stimulate ovulation in laying hens at the end of their reproductive cycle.