Association of Pit-1 gene polymorphism with milk production traits in Iranian proved Holsteins

A total of 130 Iranian proved Holstein were used to study polymorphisms of the pituitary transcription factor (Pit-1) gene. The genotypes were detected by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The allelic frequencies were 0.321 and 0.679 for A and B alleles of Pit-1 gene, respectively. There was significant association (P 0.05) between protein yield and observed Pit1-HinfI genotypes. No significant association (P 0.05) was found between Pit1- HinfI with other milk production traits. These results revealed that detected Pit1-HinfI genotypes had significant effects on milk protein yield and can be used as a marker for this trait. It may be necessary to carry out further studies with larger sample sizes to make a clear relationship between mentioned gene variants and milk production traits.