Lack of evidence for association between the leptin/ Sau3A I gene and milk yield traits in Holstein Friesian dairy cattle

• Published in: Journal of dairy research 2023-11, Vol.90 (4), p.339-342
• Main Authors: Kibar, Mustafa, Aytekin, İbrahim
• Format: Article
• Language: English
• ISSN: 0022-0299; 1469-7629
• DOI: 10.1017/S0022029923000717

This study aimed to investigate the effect of leptin gene polymorphism and some environmental factors on milk production traits. Blood samples from 212 Holstein Friesian dairy cattle reared on a private farm were used. The intron 2 region of the leptin gene was digested with I restriction enzyme using the PCR-RFLP method. A and B alleles and AA, AB, and BB genotype frequencies for the I polymorphism were determined as 0.8821 and 0.1179, and 0.764, 0.236 and 0.000, respectively. Chi-square analysis revealed that the leptin gene polymorphism followed the Hardy-Weinberg equilibrium, including the absence of animals with the BB genotype. The effect of leptin gene polymorphism on all milk production traits was insignificant. For milk production traits, direct heritability ( ) varied between 0.03 ± 0.283 (for the dry period) and 0.50 ± 0.183 (for milk conductivity). Regarding the milking time (MT), the estimated breeding values (EBVs) of cattle with the AA genotype were higher than the AB genotype ( < 0.05). As a result of this study, in the selection program, allele or genotype could not be suggested as a marker for milk yield characteristics except for the possible exception of milking time and its relationship to mastitis incidence.