A Research On Association Between Scd1 And Olr1 Genes And Milk Production Traits In Iranian Holstein Dairy Cattle

The present study was carried out to investigate the association of C/T single nucleotide polymorphism (SNP) in exon 5 of stearoyl-CoA desaturase 1 (SCD1) gene and A/C SNP in the 3' untranslated region of oxidized low density lipoprotein receptor 1 (OLR1) gene with milk production traits in Iranian Holstein dairy Cattle. The blood samples of 153 (for OLR1) and 308 (for SCD1) dairy cattle from three different farms were used for genotyping. A 146 bp fragment of 3' UTR of OLR1 gene and a 400 bp fragment of exon 5 of SCD1 gene were amplified by standard PCR. Single nucleotide polymorphism of OLR1 and SCD1 gene was determined by polymerase chain reaction single-restriction fragment length polymorphism (PCRRFLP) technique. The association between genotypes of OLR1 and SCD1 genes with milk production traits was studied by general linear models (GLM) procedure of SAS package and Duncan test was used for comparing means of traits. The frequency of AA, AV and VV genotype of SCD1 gene were 0.60, 0.32 and 0.08 respectively. The frequency of alleles A and V were 0.76 and 0.24. The genotype frequencies of AA, AC and CC in OLR1 gene were 0.22, 0.50 and 0.28 respectively. The frequency of allele A and C was 0.47 and 0.53. Thus, this population was in Hardy-Weinberg equilibrium for OLR1 but not for SCD1. The means of fat percentage for SCD1 genotypes were 3.43% and 3.33 for VV and AA respectively (P<0.05). The means of OLR1 genotypes were 8273 kg (CC), 8344 kg (AC) and 7178 kg (AA) for milk yield; 276.3 kg (CC), 277.6 kg (AC) and 239.7 kg (AA) for fat yield and for protein yield were 286.7 kg (CC), 290.5 kg (AC) and 253 kg (AA) (P<0.05). The results revealed these two SNP are appropriate for marker assisted selection.