El virus de la leucosis bovina disminuye la producción y calidad de leche en ganado Holstein.

Bovine leukemia virus (BLV) belongs to the retrovirus family, the virus is characterized by being immunosuppressive. Its infection is systemic and occurs more frequently in dairy cattle. Productive information was obtained from 1021 records of 500 Holstein cows. The animals were distributed in 7 municipalities of the department of Antioquia dedicated to the production of milk. Four productive characteristics were analyzed: milk production (PDN), kilograms of protein per lactation (KGPRO), kilograms of fat per lactation (KGGRA) and somatic cell score (SCS); these characteristics were associated with BLV infection through a generalized linear model. The results indicate that the relationship between the presence or absence of BLV was significant (P <0.05) for milk and fat production, but not for protein production (P=0.1644) and SCS (P=0.0546). The infected cows had a lower milk production per lactation (7.67%), less protein (15.37 kg/ lactation) and more fat (23.67 kg/lactation). No difference was found between SCS between infected and uninfected cows. The negative effect of BLV on infected cattle affects the productive parameters and profitability of dairy farms. [ABSTRACT FROM AUTHOR]