Detection of polymorphism of growth hormone gene for the analysis of relationship between allele type and growth traits in Karan Fries cattle

The present study was conducted to detect polymorphism at growth hormone gene in Karan Fries bulls. A 428 bp fragment of growth hormone gene spanning over 4(th) exon, 4(th) intron and 5(th) exon was amplified and digested with AluI restriction enzyme to identify polymorphism at this locus. Karan Fries bulls were found to be polymorphic at this locus. Two genotypes LL and LV were identified in Karan Fries with higher allelic frequency for L allele. In Karan Fries males, the average birth weight, 3 months body weight and daily body weight gains of LL homozygotes were significantly higher than that of LV heterozygotes. Genetic distances of KF bulls with respect to genotype along with 3 months body weight and average daily body weight gain forms a single cluster of bulls with LL genotype, while individuals with LV genotype forms three distinct clusters indicating more influence of L allele on growth traits.