| possible effect of altered management practices on seroprevalence of bovine leukemia virus in heifers of a dairy herd with history of high prevalence of infection. | a bovine leukemia virus (blv) control program was instituted at a high-prevalence, purebred holstein dairy. the specific control program required single use of needles and obstetrical sleeves, disinfection of tattoo equipment before use, dehorning by use of electrical burning devices, replacement of whole milk feeding with high-quality milk replacer, and heat treatment of colostrum before feeding. the effect of the program was estimated by comparing the pre- (1987) and postintervention (1989) pr ... | 1991 | 1664821 |