Association between IGF-1 gene polymorphism and milk production traits in Polish Red-and-White cattle

The aim of this study was to analyze polymorphism C– 512T in the IGF-1 gene in relation to milk production traits in Polish Red-and-White cattle. Traits analyzed were: milk yield, content of fat, protein, lactose, dry matter and somatic cell count. Polymorphism analysis showed presence of 2 alleles in the investigated herd with frequency C – 0.51, T – 0.49. Association analysis showed that cows with CC and CT genotypes are characterized by higher milk yield in the second lactation comparing to those with TT genotype. Moreover, CC genotype was favorable for somatic cell count.