Comparative analysis of genetic polymorphism of blood proteins in holstein and simmental breeds of cattle

Purpose: to study genetic polymorphism of blood proteins in Holstein and Simmental cattle breeds. Materials and methods. The blood of Simmental (n=368) and Holstein (n=266) cows served as the material for the study. Blood samples were analyzed by vertical electrophoresis in a two-layer polyacrylamide gel, where the following polymorphic proteins were analyzed: transferrin (Tf), posttransferrin-1 and 2 (Ptf-1 and 2), hemoglobin (Hb), amylase (Am), catalase (Kt), prealbumin (Pa). Results. Simmental cattle retain polymorphism of the hemoglobin locus, while in Holstein cattle it remains monomorphic. The Holstein breed is characterized by a high frequency of the Tf A allele and a low frequency of the Tf E allele, as well as the absence of the Am A allele in comparison with the Simmental breed. In the studied cattle populations, a violation of the genetic balance is observed at four loci in the Simmental breed (Tf, Kt, Pa, Am) and at two loci in Holstein cattle (Ptf-1 and Am) due to an excess of homozygous genotypes. The number of effective alleles per locus in the studied breeds averaged 1,79 (in Holsteins) and 1,82 (in Simmentals). The highest value of the number of effective alleles was observed at the transferrin locus (3,00—3,03).