The relationships between leptin gene polymorphism and some performance traits in Simmental and Brown Swiss cattle

Abstract

Abstract This study was carried out to determine the genotype and allele frequencies and association between the Leptin gene Sau3AI polymorphism and some performance characteristics in Simmental (n=60) and Brown Swiss (n=62) breed cattle raised in the province of Erzurum, Turkey. In the study, leptin/Sau3AI gene polymorphisms in DNA isolated from blood samples obtained from Simmental and Brown Swiss cattle were determined using PCR-RFLP method. As genotype frequencies of leptin/Sau3AI gene in the population, in Brown Swiss cattle, 88,7% with genotype AA, 9,7% with AB and 1,6% with BB genotypes were determined, Simmental breed cattle, 78,3% with genotype AA, 16,7% with AB and with 5,0% BB genotypes were determined. AA genotype frequencies were the highest in the population, and those with BB genotypes had the lowest frequency in both breeds. When the population was examined in terms of allele frequencies, the A allele was 0,87 and B allele was 0,13 in the Simmental cattle, and the A allele was 0,94 and B allele was 0,06 in the Brown Swiss breed. According to Hardy-Weinberg genetic balance test, the distribution of genotype frequencies was balanced (P>0.05) in the Brown Swiss breed but not in the Simmental breed in the population studied. As a result of the analysis performed in the Simmental breed, the general averages were found to be 5422,4 ± 1901,74 kg for actual milk yield, 5626,6 ± 1475,85 kg for 305-day milk yield, 298,7 ± 84,80 days for lactation duration and 18,5 ± 4,84 kg for daily milk yield. According to the statistical analysis results, the effect of genotype on the actual milk yield during lactation, lactation duration and daily milk yield was significant. As a result of the analysis made in the Brown Swiss breed, the general averages were 3917,8 ± 1584,38 kg for actual milk yield, 4614,3 ± 982,62 kg for 305 days milk yield, 254.9 ± 99.88 days for lactation duration and 16,0 ± 3,82 kg for daily milk yield. According to the statistical analysis results, the effect of genotype on performance characteristics was insignificant in Simmental and Brown Swiss cattle.