Abstract
Background: Dairy sector is one of the leading in agricultural production in the world and the bovine herpesvirus 1 (BoHV-1) is an important pathogen that causes great losses in most production systems. Moreover BoLA DRB3 immunological gene that presents different alleles related whit protection against many pathogens.
Methods: Serological diagnosis was made for determine BoHV-1 infection and through PCR-RFLP five hundred six Holstein cows from several municipalities of Antioquia were genotyped for BoLA DRB3.2 gene polymorphisms.
Results: Alleles 8, 16, 22 and 24 were the most common out of the 42 found. By indirect ELISA technique a prevalence of 58.7% of BoHV-1 infection in this population was diagnosed, and OR for found alleles were calculated by logistic regression; the only significant association was held for allele 37, showing that its effect confers susceptibility to infection. On the other hand, using generalized linear models, significant association between BoLA DRB3.2 gene and milk and fat yield in primiparous and services per conception in multiparous was found, being the most favorable alleles 11 and 28 in primiparous, and 22 and 28 in multiparous; 37 allele was unfavorable only in primiparous.
Conclusions: BoLA DRB3.2 gene polymorphisms have shown high variability and significant effects on Holstein cattle and their performance in production systems in Antioquia, both at sanitary or health and productive level.

Key words: Holstein, immunity, prevalence, production, reproduction.