Marking of Genetic Resistance to Chlamydia, Brucellosis and Mastitis in Holstein Cows by Using Polymorphic Variants of LTF, MBL1 and TLR9 Genes

The purpose of the research is to study the association of polymorphic variants of the Toll-Like Receptor 9 (TLR9), Mannose-Binding Lectin 1 (MBL1), and Lactoferrin (LTF) genes with the incidence of chlamydia, brucellosis and mastitis in Holstein cows. Samples of Holstein cows with established diagnoses of chlamydia, brucellosis, and mastitis were characterized by the nature of the correspondence of the observed frequencies of genotypes theoretically expected by the Hardy Weinberg law, by the percentage of genotypes in comparison with the control group of healthy animals, as well as by the nature of the distribution of relative frequencies of alleles of the studied genes. It was found that the genotypes TLR9-BfaI^AA and MBL1-HaeIII^CC were the genetic markers of increased resistance to chlamydia. The genotypes TLR9-BfaI ^AG and MBL1-HaeIII^TT were the genetic markers of an increased risk of chlamydia. The genotypes MBL1-HaeIII^TT and LTF-EcoRI^AA were the genetic markers of an increased risk of brucellosis. The genotypes MBL1-HaeIII^TC and LTF-EcoRI^AB were the genetic markers of increased brucellosis resistance. The LTF-EcoRI^AA genotype was a genetic marker of an increased risk of mastitis and the LTF-EcoRI^AB genotype marked increased resistance to mastitis in Holstein cattle.