Hyperimmune bovine colostrum neutralizes Cryptosporidium sporozoites and protects mice against oocyst challenge

Activity of colostral whey, produced by a cow immunized with oocysts of Cryptosporidium parvum and found to provide prophylaxis against cryptosporidiosis in calves, was tested in 2 experiments. In one experiment BALB/c mice were given the immune whey (HW), whey from a nonimmunized cow (CW), or a balanced salt solution (HBSS) before, during, and after oral inoculation with oocysts of C. parvum. Significantly fewer (P < 0.05) C. parvum were found in mice that received HW (undiluted, 1:20 or 1:50) than in those treated with similarly diluted CW or with HBSS. In the second experiment it was determined that protection was mediated by specific anti-sporozoite activity when significantly fewer (P < 0.05) C. parvum were found in mice that received sporozoites treated with HW diluted 1:20 or 1:50 compared with mice that received sporozoites treated with similarly diluted CW or with HBSS.