Efficacy of a flexible schedule for administration of a Leptospira borgpetersenii serovar Hardjo bacterin to beef calves.

Objective: To determine whether a flexible vaccination regimen provides protection against challenge exposure with a virulent Leptospira borgpetersenii serovar Hardjo isolate.

Animals: Fifty-five 4-week-old calves seronegative for antibodies against L borgpetersenii serovar Hardjo.

Procedures: Calves were assigned to 3 groups and administered 2 doses of adjuvant (control calves; n = 11), 1 dose of serovar Hardjo bacterin and 1 dose of adjuvant (22), or 2 doses of the serovar Hardjo bacterin (22); there was a 16-week interval between dose administrations.

Effect of subcutaneous administration of a killed Mycobacterium avium subsp paratuberculosis vaccine on colonization of tissues following oral exposure to the organism in calves.

OBJECTIVE-To evaluate the effect of vaccination of calves with a killed Mycobacterium avium subsp paratuberculosis (MAP) vaccine on colonization of tissues following oral MAP exposure. ANIMALS-12 healthy Holstein calves. PROCEDURES-At 14 days after birth, calves received the MAP vaccine (1.