Effects of Leptin Gene Polymorphism on Beef Cattle Performance

Livestock specialized cattle breeds combining high energy for both growth and fattening performance are successfully used for high-quality beef production. The use of DNA markers as the additional criteria for sampling and mating the animals allows us to increase the efficiency of selection processes along with improving the meat characteristics of cattle. The objective of the survey was to estimate the effects of leptin gene polymorphism on the growth rates of youngstock and the product quality of beef cattle. The practical science experiment was carried out in 2014–2017. The fattening Hereford and Limousin bull calves (114 and 111 animals, respectively) were genotyped with the technique of polymerase chain reaction (PCR) and subsequent PCR-restriction fragment-length polymorphism analysis (SNP LEP-A422B). A similar genotype distribution among the animals was revealed. Homozygous genotype LEP AA (47.34% and 52.25%, respectively) and allele LEP 4 (frequencies of occurrence are 0.68 and 0.71, respectively) are more frequent. The liveweight in both cattle breeds with genotype LEP AA tended to increase at the ages of 8, 12, 16, and 20 months. In addition, an insignificant predominance in body measurements used to assess the proportions of their body parts was ascertained. The analysis of the body conformation indices could indicate harmonious animal development and prove the well-expressed beef forms in the youngstock of all the genotypes for the leptin gene. The postslaughter assessment allowed us to reveal the tendency to increasing the values for the preslaughter liveweight, the hot carcass weight, and the slaughter weight. In addition, the increased carcass yield was recorded in the Hereford bull calves with genotype LEP AA . The surveys ascertained a significant relationship between the analyzed polymorphism and the increases in the internal crude fat weight and the fat yield in the carcasses of bull calves with genotypes LEP AB and LEP BB . The analysis of the morphological composition of Hereford bull calf carcasses revealed a significant relationship between genotype LEP BB and fat contents. Therefore, SNP LEP-A422B genotyping may be used in Hereford and Limousin cattle breeding to improve the meat quality parameters.