Resumen

USUGA-MONROY, C.; ECHEVERRI, J. J.  y  LOPEZ-HERRERA, A.. The racial component influences resistance to infection with the bovine leukemia virus. Rev. Med. Vet. Zoot. [online]. 2018, vol.65, n.2, pp.130-139. ISSN 0120-2952.  https://doi.org/10.15446/rfmvz.v65n2.75632.

The bovine leukemia virus (BLV) is a retrovirus that primarily affects dairy cattle, reducing milk production between 2.5 and 5%. The Colombian Blanco Orejinegro (BON) is a well-adapted, rustic, creole breed resistant to in vitro infections of Foot-and-mouth disease virus and vesicular stomatitis virus, as well as to Brucella abortus. This study aimed to determine if the crossing of BON and Holstein breeds is resistant to infection by BLV. Blood samples of 124 individuals (59 Holstein, 40 BON, and 25 BON x HOL) of the same herd were taken. The DNA was extracted, and a nested PCR was performed related to a region of the env gene of BLV. A fragment of 444 bp was obtained for positives animals. The molecular in-herd prevalence was 33% for BLV. A significant difference for BLV infection was found among the groups (p<0.05). The infection rate for the Holstein group was 55.9%, for BON cattle 5%, and for BON x HOL cattle 24%. The latter showed a reduction in the infection rate of 32% to the Holstein breed, which can be attributed to the presence of resistance genes in the BON breed. It was found that the level of infection is lower in BON x HOL cattle in contrast with Holstein dairy cows.

Palabras clave : nested PCR; resistance; bovine leukemia virus.

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