Association of leptin gene polymorphism with economic traits in crossbred cattle

The present investigation was carried out to identify two polymorphisms in leptin gene by PCR-RFLP and to examine the possible association of the identified genotypes with growth, production and reproduction traits in 205 female crossbred cattle (½ Holstein Friesian × ½ Hariana). One fragment of 330 bp comprising partial intron 2 and exon 3, and another fragment of 94 bp comprising partial exon 2 of leptin gene were amplified, and digested with HphI and Kpn2I restriction enzymes, respectively, for identification of genotypes. The animals with HphI-RFLPCT and Kpn2I-RFLP-AV genotypes had significantly higher birth weight than the HphI-RFLP-CC and Kpn2IRFLP-AA genotypes respectively. The HphI-RFLP locus had significant effect on body weight at 12 months of age, age at first calving and average daily milk yield, while, Kpn2I-RFLP had significant effect on first lactation milk yield and average daily milk yield. Therefore, leptin gene could be used as a marker for genetic selection of economic traits in cattle.