Polymorphisms of growth hormones gene and their associations with growth traits of crossbred pigs in humid tropical environment

Abstract

This study was undertaken to identify and analyse the polymorphism of growth hormone genes in pigs and to determine the associations of these growth hormone genes with growth traits such as body weight and linear body measurement of crossbred pigs. Blood of sixty (60) randomly selected crossbred pigs from six different genotypes (Local pigs x Local pigs, Landrace x Landrace, Large white x Large white, Local pigs x Landrace, Local pigs x Large white and Large white x Landrace) was used for DNA extraction. Polymerase Chain Reaction (PCR) was performed. Sequences were aligned and Single Nucleotide Polymorphism (SNPs) detected using Mega 6.0. DNA polymorphism was determined by DNAsp version 5 and the association between growth traits and growth hormone genes was done using Genstat v12. The effects of G>A mutation and interaction of growth hormone genes (GH) on growth performance of crossbred pigs at birth, weaning (6 weeks) and 16 weeks were obtained, with no significant differences (P>0.05) between genotypes GG (normal) and GA (mutant) among the pigs in association with body weight (BW) and linear body measurements. Results revealed that GH gene genotype GA had higher growth trait values than genotype GG at birth, weaning and 16 weeks. Consequently, these SNPs may be useful indicators in selection of pigs for higher growth rate and meat production. GA genotypes had a stronger correlation to higher body weight than GG genotypes in pigs.

Key words: GH gene, genetic polymorphism, body measurements, Crossbred pigs