Response of Golden Brown Bovans Layers to GnRH (Cystorelin) through I.M. Injection Indicated by the Reproductive Traits

The study was conducted on 84 layer hens (golden brown bovans) at age of 34 weeks old, suffered from inactive ovaries, and they were brought from Kanakawa project farms. The research was done from 16 February 2010 to 16 March 2010 at the University of Sulaimani College of Agriculture. In this research injection of cystorelin hormone which contain 50 μg of GnRH in each ml. Postmortem examination of 4 chickens randomly chosen were done before treatment and samples from the ovaries were taken for gross and histopathological examination. A dose of 0.02ml (1 μg) of hormone was used to treat the condition of inactive ovaries, chickens in the experiment were divided as following; 1- Control group (n= 21) injected by 0.02 ml of distal water, 2- First treatment group (T1) (n=21) injected by 1 μg (0.02ml) of hormone in 4 days intervals, 3- Second treatment group (T2) (n= 21) injected by 1 μg (0.02ml) of hormone in 7 days intervals, 4- Third treatment group (T3) (n= 21) injected by 1 μg of hormone (0.02ml) in 10 days intervals. Different positive responses had been shown in treated groups. The results showed that the second group (T2) had a higher positive response (20.38±1.45) eggs/week and recorded higher significant differences at P 0.05, while first group (T1) showed response (11.44 ±1.45) eggs/week. Poor response was observed in the third group (T3) (8.12±1.45) eggs/week. It was concluded from this study that treatment of inactive ovaries in layer hens by injection of (10 μg Cystorelin) in seven days intervals gave the best result.