Evaluation of the Effect of Mycotoxins in Naturally Contaminated Feed on the Efficacy of Preventive Vaccine against Coccidiosis in Broiler Chickens

Abstract

This research was designed to evaluate the effect of naturally contaminated feed with mycotoxins on the efficacy of vaccination against coccidiosis in broilers. Two hundred day-old Hubbard broiler chicks were divided into four groups (50 chicks/group). Group 1 and 3 were kept on naturally contaminated diets containing 4 ppb aflatoxin, 3 ppb ochratoxin, 1 ppm zearalenone and 2 ppb aflatoxin, 6 ppb ochratoxin and 1 ppm zearalenone in starter and grower feed, respectively. Groups 2 and 4 were fed on diet without detectable levels of mycotoxins. Group 1 and 2 were vaccinated with anticoccidial vaccine at 4 days of age. All groups were challenged with Eimeria tenella (5×104/chick) 14 days post-vaccination. Vaccinated mycotoxicated birds showed a significant reduction in body weight, high mortality, significant oocysts shedding, severe hemorrhagic typhlitis, marked lymphoid depletion in bursa of Fabricius and degenerative changes in liver and kidney. In addition, a remarkable decrease in length and width of intestinal villi, mucosal length and crypt depth. Feed contamination with multi-mycotoxins in permissible level caused vaccination failure and a remarkable decrease in intestinal morphometric histopathological parameters.