CORRELATION ANALYSIS BETWEEN MYOSTATIN GENE POLYMORPHISMS AND CARCASS TRAITS IN NEW ZEALAND ROMNEY SHEEP

Abstract

Using genetic markers can aid identifying those animals with the highest values for economically important traits in sheep. The current study was designed to detect the allelic and genotypic polymorphisms of the intron 1 of myostatin gene and to test their associations with carcass traits (slaughtering weight, dressing%, shoulder yield, loin yield, leg yield, total yield, shoulder yield%, loin yield% and leg yield%) in 529 male lambs of New Zealand Romney sheep. The polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis was used to identify the allelic and genotypic polymorphisms in intron 1 of myostatin gene for 529 males from New Zealand Romney lambs. Associations of the variation in the intron 1 of myostatin gene with carcass traits were determined using the general linear model (GLM) procedure of SAS (2000). The SSCP analysis revealed six SSCP genotypes: AA, AB, AC, BB, BC and CC with frequencies of 0.107, 0.368, 0.100, 0.289, 0.129 and 0.005, respectively, that derived from three identified alleles: A, B and C with frequency 0.34, 0.54 and 0.12, respectively. Myostatin genotype significantly affected (P˂0.05) slaughtering weight and total yield, and highly significant affected (P˂0.001) dressing%, leg yield, shoulder yield%, loin yield% and leg yield%. The presence of A allele in animal genotype was associated with higher leg yield and leg yield%, however, the presence of B allele was associated with higher loin yield and loin yield%. The LSM showed that, lambs with two copies of A allele had the highest dressing%, leg yield, leg yield% and total yield, however, lambs with two copies of B allele had the highest shoulder yield, shoulder yield% and loin yield%. The results presented here give valuable information to select for A and B alleles and against C allele to improve the most important primal cuts of lambs across most production systems.