Abstract

Two experiments were conducted to study the effect of uropygial gland removal in overcome the problem of delayed sexual maturity in commercial lying hens stocks. The first experiment was carried out at Alnahrwan poultry farm from 1-3-2005 to 28-2-2006. A total of 25000 Isa Brown laying hens were divided into two treatment groups. The first group which consist of 20000 hens were used as control group (T1). The second group (T2) which consist of 5000 hens were subjected to surgical removal for uropygial gland at 24 weeks old. Hen day (HD) egg production were calculated monthly throughout the experimental period which was lasted for One year. The data from this experiment showed that egg production percentages and cumulative egg production were gradually increased for T2 hens after Uropygialectomy. There were no significant differences between the two treatment groups for the lasted eight months from the production year.
The second experiment was carried out at Al-Haramen poultry farm at Karbala governorate from 1-12-2007 to 30-9-2008. A total of 9000 Hisex Brown Laying hens were divided into two groups. The first group which was consist of 6000 hens was used as control group (T1). The second group (T2) which was consist of 3000 hens was subjected to surgical removal for uropygial gland at 28 weeks old. Egg production and cumulative egg production were calculated monthly throughout the experiment period which was lasted for 10 months. The data showed that egg production percentages and cumulative egg production were gradually increased in second group. There were no significant differences between the two treatment groups for the last three months. Blood serum estradiol concentration were significantly (P> 0.05) increased in uropygialectomized hens when compared with non treated hens.
The overall results for the present study suggested that uropygialectomy were benefit in overcome the delayed sexual maturity in commercial laying stocks.