Polymorphism of the Growth Hormone Gene and Its Effect on Production and Reproduction Traits in Goat

Growth hormone (GH) has an effect on a broad variety of physiological parameters such as lactation, reproduction, growth and metabolism. Thus, the aim of this study was to detect GH gene polymorphism and its association with breeding values of production and reproduction traits in Raini Cashmere goat. Breeding values were estimated using records on 26731 Raini Cashmere goats. To study GH gene polymorphism, 300 animals were selected based on their estimated breeding values (EBVs) for these traits. Then the animal’s genotype was determined using PCR-RFLP. The genotype frequencies for AA, AB and BB were 0.15, 0.85 and 0, respectively. The number of observed alleles, number of effective alleles, expected heterozygosity, observed heterozygosity, mean of heterozygosity, expected homozygosity, observed homozygosity, Nei’s index, Shanon’s index and Fixation index (Fis) were 2, 1.96, 0.49, 0.85, 0.49, 0.51, 0.15, 0.49, 0.69 and -0.74, respectively. Results showed that mean estimated breeding values for birth type, fleece weight and birth weight traits in different genotypes varies, of course these differences were not statistically significant (P>0.05). However, for fleece weight and birth type traits AB genotype had higher EBV. Due to the relatively high diversity of growth hormone gene in Raini Cashmere goat and its association with important economic traits, using growth hormone gene in breeding programs of this breed can lead to acceptable genetic progress and applying AA genotype for birth weight trait and AB genotype for fleece weight and birth type traits can be used as an indirect marker for selection of superior animals.