Colostral transfer of Bacteroides nodosus antibodies in sheep.

Ovine contagious foot rot may cause lameness in sheep, resulting in decreased wool growth and low weight gain. Affected neonatal lambs are difficult to treat, and treatment is labor intensive; thus, a method of prevention is warranted. Vaccination of ewes with a multivalent vaccine in an oil adjuvant induced development of antibody to the somatic O antigen of Bacteroides nodosus, and this antibody was detected in serum of newborn lambs after consumption of colostrum from the vaccinated ewes. Antibody titers were determined in 48 unvaccinated ewe/lamb pairs, and in 50 once-vaccinated and 78 twice-vaccinated pairs. Serum and colostrum O-agglutinin titers to B nodosus were determined by a microtitration agglutination test. Lambs from vaccinated ewes had significantly (P less than 0.05) higher O-agglutinin titers than those from unvaccinated ewes, and double vaccination of ewes resulted in the highest potentially protective titers (greater than 1:2,400) in ewes and lambs.