Polymorphism of calpain 1 CAPN1 530 gene in connection with meat productivity of cattle of hereford and limousin breeds
The article presents the results of genotyping of cattle of Hereford and Limousin breeds for SNP САРN1-А530G and determination of the association of this polymorphism with indicators of meat productivity. The research aimed to study the effect of SNP CAPN1530 on the traits of meat productivity in cattle of the Limousin and Hereford breeds. The frequency of occurrence of the desired GG genotype in animals of the Hereford breed was 58.97%, in the Limousin breed - 52.78%; allele G - 0.77 and 0.72, respectively. Live-animal productivity estimation indicated the absence of significant differences in live weight, average daily, absolute live weight gain and relative growth rate in bulls of different genotypes for the CAPN1 gene in postnatal ontogenesis. At the same time, in most cases, there was a steady trend towards an increase in the values of the studied indicators in bull-calves of both breeds, depending on the genotypes, in the direction AA < AG < GG. An assessment of the meat qualities of carcasses also indicated the absence of significant intergroup differences in terms of pre-slaughter live weight, fresh carcass weight and slaughter weight against the background of a pronounced upward trend in their values in animals with the GG genotype. Significant intergroup differences were determined in terms of the indicator characterising the structural and mechanical properties of the longissimus dorsi muscle. The force to cut the muscle tissue of animals with the GG genotype, compared with individuals with the AA genotype, at the end of the first day after slaughter was lower by 6.3% (Hereford breed) and 6.4% (Limousin breed) (p<0, 05); on the third day of the experiment - by 8.1% and 8.3%, respectively. This fact indicates that the meat of animals with the GG genotype was of the best quality in terms of tenderness. Thus, the established relationship between the GG genotype and the index characterising meat tenderness, along with the high frequency of occurrence of the desired genotype in domestic generations of livestock, can be successfully used in selection and breeding work with Hereford and Limousin breeds.