The effect of administration of anti-coccidial drugs on oocystshedding and performance in experimental coccidiosis inbroiler chickens

Coccidiosis is one of the major parasitic diseases of poultry. in this study, to compare theeffects of coccidiostatic drugs on fecal oocyst shedding and body weight gain of coccidi-infectedbroiler chickens, 180 one day old ross 308 broiler chicks were randomly assigned to fourtreatments. each treatment contained 3 replicates of 15 chickens. treatments 1 and 2 were feddiets supplemented with 200ppm diclazuril and 500ppm salinomycin, respectively.treatments 3 and 4 were designated as positive and negative control, received no coccidiostate.chickens in treatment 1, 2 and 3 were inoculated with a suspension containing four eimeriaspecies. frequency of excreted oocyst obtained from feces samples during 7-13 days post -challenged was carried out. body weight, body weight gain, feed conversion ratio and mortalityrate were evaluated weekly. the results revealed that coccidiostatic drugs decreased oocyst pergram of feces significantly in 7-13 days post inoculation (p<0.05). the highest mean of bodyweight was related to negative control followed by chickens treated with diclazuril. the lowestfcr was belonged to negative control followed by chickens treated with diclazuril. it could beconcluded that coccidiostate -supplemented diets in eimeria infected groups shed less (p<0.05)oocyst than control-infected chickens and improved production performance in coccidianinfectedbroiler chicks.