Genetic polymorphism of the growth hormone gene and their effects on growth metrics in the Assam Hill and Sirohi goats under subtropical climatic condition

Abstract

AbstractGrowth hormone (GH) is a gene that regulates milk production, reproduction, and growth in animals. Therefore, the purpose of this study was to identify GH gene variations and their associations with growth metrics in Sirohi and Assam hill goats. We identified two polymorphic loci (GH1-HaeIII & GH2-HaeIII) which were connected to growth attributes in 161 animals of Assam hill (n = 114) and Sirohi (n = 47) goats using the methods of PCR-RFLP. According to PCR-RFLP results, the GH gene's GH1-HaeIII locus contains two alleles (A and B) and two genotypes (AA and AB), whereas the GH2-HaeIII locus contains two alleles (C and D) and two genotypes (CC and CD). In the two goat breeds, the allele frequencies of A and B were 0.36 − 0.28 and 0.64–0.72, respectively, while the frequencies of alleles C and D were 0.71 − 0.70 and 0.29–0.30. The polymorphic loci were demonstrated to be in a state of Hardy-Weinberg disequilibrium in both breeds of goats (P < 0.05). The growth characteristics of the Assam hill goat breed were shown to be correlated with GH gene variations. In both breeds, AB and CD genotypes displayed slightly higher values in most of the morphometric traits compared to AA and CC genotypes; however, only in Assam hill goats body length and chest girth were positively significant (P < 0.05). Hence, the AB and CD genotypes have been proposed as potential markers for improved growth parameters in the breeds that were tested. Therefore, we came to the view that the two variant loci of the GH gene will utilize as marker assisted selection for enhancing growth attributes in goats; however, more research with a bigger sample size is necessary to verify the validity of this conclusion.