Effect of Polymorphism of the Gonadotropin-Releasing Hormone I (GnRHI) Gene on some Productive Traits of Iraqi white Local Chickens

Abstract

This study was conducted in the poultry field of the Ministry of Science and Technology / Livestock and Fisheries Center / Poultry Department. In order to study the effect of polymorphisms of the gonadotropin-releasing hormone I gene (GnRH I) and a study of the possibility of the effect of this gene on the growth and productive traits of the local white Iraqi chicken birds, and the results showed that the two genetic morphologies S1 and S2 were superior to the genetic morphology S3 in each trait, the average weight of the first egg. Body weight at sexual maturity, age at maturity, and egg production for a period of 100 days at a significant level (P > 0.01), while no significant differences were recorded between the two genotypes S1 and S2 in each of the above traits. The average weight of the first egg was 33.85, 33.14 for each of the two genotypes S1 and S2, while it was 30.22 for the genotype S3, and the average body weight at sexual maturity and the number of eggs produced for 100 days for the genotype S1 was 1395.18g, 54 eggs and 1369.36 g, 52.74 eggs of the S2 genotype, which excelled on the S3 genotype, in which the average traits were 1230.57 g, 43.89 eggs. As for the trait of age at sexual maturity, it is noted from the table that the S3 genetic morphology was distinguished in the characteristic of early age at sexual maturity, reaching 127.58 days for the S3 morphology, while the rates of the trait for the S1 and S2 morphogenesis were 148.82, 147.83 days, respectively.