Growth hormone gene polymorphisms in native hair goats and its relationship with growth traits

This study was carried out on Hair goat kids to determine polymorphism for two different region of growth hormone gene (GH1 and GH2) and to determine difference between GH1 and GH2 genotypes for growth traits of kids. Animal material of study consisted of 297 head of kids from 8 farm at villages of Aydın and Denizli provinces. Birth weight, live weight at 3.5 and 5.5 months of age, and average daily gains between birth and 3,5 and 5.5 months of age were recorded for all kids to determine change of growth traits of kids according to genotypes. PCR products of 422 and 116 bp were obtained for GH1 and GH2 regions of GH gene, respectively, by use of spesifically designed primers. Then, both PCR products were digested with same restriction endonucleases enzyme, HaeIII, to determine nucleotide polymorphisms. DNA fragments of PCR-RFLP products obtained from enzyme digestion were separated by gel electrophoresis and visualized. As a result of analysed genotype data that obtained from images, genotype frequencies of 0.19, 0.65 and 0.16 were obtained for AA, AB and BB genotypes of GH1 region and allele frequencies of 0.51 and 0.49 were obtained for A and B alleles, respectively. Genotype frequencies of 0.16, 0.68 and 0.16 were obtained for CC, CD and DD genotypes of GH2 region and allele frequencies of 0.50 and 0.50 were obtained for C and D alleles, respectively. Analysis of growth performances of kids according to GH1 and GH2 genotypes have shown that there are no statistically significant effects of the nucleotide polymorphism at investigated regions of growth hormone gene on growth performances of kids from birth to age of 5.5 months.