Virginiamycin effects on controlling necrotic enteritis infection in chickens.

Duplicate trials were conducted with male broiler chickens to evaluate virginiamycin as treatment against experimentally induced necrotic enteritis infection. Each trial consisted of seven treatments, each replicated four times, with 10 birds per replicate. Two treatments were fed control ration (noninfected control and infected control) and the five remaining treatments were fed virginiamycin at 5, 10, 15, 20, or 40 g/ton. Birds were orally dosed with 10 ml of Clostridium perfringens culture at 14 days of age. At 5 weeks of age, surviving birds were killed and necropsied to obtain lesion scores. Birds fed virginiamycin had significantly less mortality and lower intestinal lesion scores than nonmedicated birds when experimentally infected with necrotic enteritis.