Association of LEPR gene Polymorphism with milk yield and age at first calv-ing in the Iranian Holstein dairy cows

The lepr is a glycoprotein expressed mainly in hypothalamus, where it takes part in energy homeostasis and in regulation of the activity of the secretory organs. a transition mutation in this gene results in substitution of cytosine by thymine leading to the substitution of threonine by methionine in the intracellular domain of the lepr-b isoform. this study investigated the impact of polymorphism located in the lepr (t945m) gene on milk yield and age at first calving traits. the analysis was conducted on 395 randomly holstein dairy cows. in the association studies, traits of interest were analyzed using the glm procedure of sas; means of the lepr genotypes were compared by the lsmeans test. statistical analyses showed no significant difference between the snp and selected traits. regarding the association revealed, thet945m snp may not be as a possible candidate for marker – assisted selection in the iranian dairy cattle breeding program.