Study of Genetic Polymorphism in Leptin Exon 3 Region and its Association with Milk Production and Reproduction Traits in Indian Sahiwal Cattle

Abstract

This study investigated the status of leptin (LEP) exon 3 polymorphism in Indian Sahiwal cattle breed (n = 124) using hphI/PCR-RFLP assay and its association with milk production and reproduction traits. The 454 bp amplified fragment upon restriction digestion revealed two types of genotypes; namely; CT genotype (454, 309 and 145 bp fragments) and TT genotype (309 and 145 bp fragments) with frequencies 29.03% and 70.97%, respectively. We could not find any CC genotype (454 bp; uncut fragments) in screened population. Allelic frequency of C and T alleles were 0.15 and 0.85, respectively. Chi square analysis revealed that screened population was not found in Hardy-Weinberg equilibrium. Association studies reveled that TT genotype was associated with shorter age at first calving (AFC) and days to reach peak yield (DRPY) in the first lactation, while TT has shorter dry period (DP) than CT genotype in all the five lactation. TT genotype was also associated with shorter calving interval (CI) in all the studied lactation except lactation I. Therefore, the present study indicating that T allele of this SNP in LEP exon 3 regions could be used as a potential genetic marker for improvement in reproduction and production performance in cattle.