Effect of stimulation of follicle growth and egg production of breeder hens with hormone injection

Hormones, such as testosterone and growth hormone (via IGFs system) control the follicular growth and egg production in poultry. This experiment was conducted to study the effect of subcutaneous injections of testosterone and growth hormone on follicular growth and egg production of Mazandaran native breeder hens (at 29 weeks old). One hundred sixty hens were used in a completely randomized design with four treatments, five replicates and eight hens per replicate. The hens were fed with a diet (20% crude protein & 2.8 Mcal/kg metabolizable energy. Treatments were: injection of hGH (100μg/kgBW); injection of testosterone (500μg/kgBW); injection of hGH (100μg/kg BW) + testosterone (500μg/kg BW); and injection of 100 μl distilled water (Control). Injection was before week 29 of hens. Follicular size, ovarian weight, oviductal length and egg production were recorded. Simultaneous injection of GH and testosterone significantly affected the size of F2 and F4 follicles compared with the control hens. Other parameters were not significantly affected by any of the treatments. Results showed that GH+testosterone can increase follicular growth.