Detection of antibodies against bovine leukosis virus in the first 6 months of age in calves fed with calostrum from sero positive dairy cows

The effect of ingestion of colostrum from cows serologically positive and negative to VLB was determined in seric titres of 12 Holstein calves from 1 to 6 months of age. The antibodies were determined by the test of immunodiffusion in agar gel and enzyme linked absorbent assay. The results showed that 6/6 animals that ingested colostrum from VLB positive cows presented antibodies at 30 days of age, which were detected by both diagnostic test. Where at 6 months of age 2/6 calves were positive, being detected only by the ELISA test. Under the assay conditions, the animals did not show transmission of the disease. This permit to conclude that is possible to control the horizontal transmission of the disease, during the first 6 months of age of the calves, if they are raised in appropriate sanitary and nutritional conditions.