Association between genetic polymorphism of growth-hormone-releasing hormone and the yield, chemical composition and technological parameters of cow milk (Brief Report)

Abstract. Somatoliberin or growth-hormone-releasing hormone (GHRH) belongs to a group of hypothalamic hormones. It induces an increase in the concentration of endogenous growth hormone in the blood serum of cattle (Løvendahl et al. 1991), increasing mean and pulsatile liberation of somatotropin and thus affecting indirectly an increase in the milk productivity of cows (Dahl et al. 1993). The study aimed at searching for associations between the variants of the GHRH/HaeIII polymorphism, described for the first time by Moody et al. (1995), and production traits in the examined herds and comparing the technological usefulness of milk obtained from cows with different GHRH genotypes. According to Szewczuk et al. (2008), above mentioned polymorphism is the transversion A→C located at the position A44C within initial part of intron 2 (GenBank acc. no. EF210074).