Protection of calves against cryptosporidiosis with immune bovine colostrum induced by a Cryptosporidium parvum recombinant protein.

摘要: The purpose of the study was to determine if immunization with a recombinant protein (rC7) Cryptosporidium parvum would induce immune bovine colostrum that protected calves against cryptosporidiosis following oral challenge C. oocysts. Late gestation Holstein cows low titers antibody p23 antigen were immunized three times 300 μg affinity purified rC7 (immune cows), or left nonimmunized (control cows). Colostrum obtained from each cow in both groups and partitioned into identical aliquots pooled control colostrum. Twelve at birth received either within first 2 h, again 12 24 h age. Each calf challenged orally 107C. oocysts age monitored for signs cryptosporidiosis. All six administered developed severe diarrhea (mean total fecal volume=8447±5600 ml) shed an average 1.87±1.66×1012C. None volume=740±750 ml, p<0.05), significantly fewer (3.05±2.26×109, p<0.05). absence 2.79 log10 (99.8%) reduction oocyst excretion indicates induced by provided substantial protection neonatal calves.