The relationship between the T945M single nucleotide polymorphism in the leptin receptor gene (LEPR) and milk production traits in Jersey cows*

Investigation was conducted on 219 Jersey cows. LEPR genotypes were established with the PCRRFLP using the TaqI restriction endonuclease. The frequencies of the threonine encoding C allele and the methionine encoding T allele were 0.79 and 0.21, respectively. The across-families analysis did not revealed any significant effect of the LEPR T945M polymorphism on milk, fat and protein yields. The significant relations were, however, found for fat and protein contents. Animals with the TT genotype were characterized by the lowest values of both traits. The within-family analysis, showed the significant effect only on milk fat content in one half-sibs group.