the efficacy of a poultry commercial anticoccidial vaccine in experimental challenge with eimeria field isolates

background: the control of coccidiosis in poultry industryis dominated by prophylactic chemotherapy; however,drug resistance is a serious problem. alternative control methodssuch as vaccination have been accepted as a practical method forcontrolling coccidiosis in chickens. considering the immunologicalvariation of eimeria strains, the efficacy of live coccidiosisvaccines may be compromised. objectives:to evaluatethe efficacy of a commercial anticoccidial vaccine in poultry,vaccination was followed by experimental challenge with 3eimeria field isolates. methods: the efficacy of livacox® qanticoccidial vaccine was evaluated on male broiler chicks,reared in battery cages. different factors including weight gain,fcr, opg (oocysts per gram of feces) and intestinal lesionscores were assessed. results: vaccinated challenged groups(vc) gained less weight than the un-vaccinated un-challenged(uvuc) birds (p£0.05). fourteen days post-challenge, theweight gain of vc groups challenged with isolate 2 differedsignificantly from its un-vaccinated challenged (uvc)counterpart; however, there were no significant differences inweight gain of groups challenged by isolates 1 and 3 with theirrespective uvc groups. lesion score and fcr weresignificantly improved in vc groups comparing with theirassociated uvc groups (p£0.05). lesion score and fcr weresignificantly improved in vc groups comparing with their uvccounterparts (p|£|0.05). conclusions: the present studysuggests that the use of live anticoccidial vaccine has thepotential for improving live weight gains and fcr; nonetheless,immunity to local eimeria species should be evaluatedseparately and in trial designs it should be more approximate tothe actual field condition.