This study was conducted at the Poultry Research Station (Abu Ghraib), General State Board of Agriculture, Ministry of Agriculture, for the period from 22 April to 30 June 2015 to study the effect of increasing concentration of blood hormone Testosterone on sex of embryos, hatching chicks sex, fertility and hatchability. 75 birds at 54 weeks age from native layer breeder (Mezo breed) were used. The birds were distributed randomly for 3 treatments add to 2 control groups each treatment contain 15 hens with 3 replicates per each treatment. Each replicate consists of 5 hens; we used 10 roosters separately for artificial insemination. Treatments were distributed as follow: First treatment C1: Control group: without injection. Second treatment C2: Control group (2), Injection subcutaneous in back of neck with 0.5 ml sesame oil/hen/week. T1, T2 and T3 treatments were injection subcutaneous in back of neck with 125, 250 and 500 µg of testosterone dissolved with 0.5 ml of sesame oil/hen/week. We used artificial insemination one time weekly. Primary and secondary sex ratio, fertility and hatchability from all and fertile eggs were studied.
Significant increasing (P≤0.0001) in hatching males and embryo males compared with two control group. Significant decreased (P≤0.0001) in fertility for T2 and T3 compared with C1, Significant increased (P≤0.0009) in hatchability from all eggs for all treatments compared with C2, significant increase in (P≤0.0001) for hatchability to fertile eggs at T2 and T3 compared with controls, while it decreased for T2 compared with C2.