Effect of testosterone and growth hormone injection before puberty on follicles size, rate of egg production and egg characteristics of the Mazandaran Native breeder hens

Abstract

Egg shell quality and egg internal quality are of major importance to the egg industry worldwide. This experiment was conducted to evaluate the effect of testosterone and growth hormone (hGH) on egg production and characteristics. The aim of this trial is to test this hypothesis that one injection of these two hormones before puberty has any effects on egg production of Mazandaran native breeder hens. Two hundred native pullet used in a completely randomized design with 4 treatments, 5 replicates and 10 hens in each box. Hens were fed on common diet and hormones injected subcutaneously based on body weight (BW). The four treatments were: 1) injection of hGH (100 ig/kg BW), 2) injection of testosterone (500 ig/kg BW), 3) injection of hGH (100 ig/kg BW) + injection of testosterone (500 ig/kg BW) and 4) injection of 100 il distilled water (control). Injection was before 5% oviposition of flock (flock puberty). Egg production and characteristics were determined. Treatments affected ovary weight, small white, large white and small yellow follicles and some egg parameters. GH and testosterone can alter follicles size in ovary, and it is concluded that GH+testosterone injection is more effective on small and large follicles.