Abstract
Longevity is a trait influenced by numerous factors, including environmental factors, animal health, and productivity, which translate into economic considerations. In addition to many others, genetic factors are also very important. One of the genes indirectly associated with longevity parameters is the growth hormone receptor gene (GHR). Therefore, an attempt was made to link polymorphism in the 5'UTR region of the GHR gene with longevity and productivity parameters, as well as the content of individual components of milk dry matter. The study was conducted among 100 individuals of the Polish White-Backed breed, covered by genetic resources conservation. The PCR-RFLP method was used. The 836 pz product was digested with the restriction enzyme AluI, and three genotypes were identified: AA, AB, and BB, with frequencies of 0.60, 0.32, and 0.08, respectively. The results obtained were compared with the utility parameters of the animals, and the following indicators were estimated: herd life, productive life, and milking life. The conducted research shows that GHR AluI polymorphism is associated with indicators of longevity, the number of milking days, milk yield, and the content of individual components of milk dry matter.