Effect of antibiotic growth promoters and anticoccidials on growth of Clostridium perfringens in the Caeca and on performance of broiler chickens

The effects of the growth promoters avoparcin and avilamycin and the ionoph ore anticoccidials maduramicin, narasin and monensin on the growth of Clost ridium perfringens (Cp) in the ceaca and on performance of broiler chickens were tested in 2 experiments. The supplements were fed as single feed addi tives or in some combinations. No clinical signs or lesions caused by cocci dia were observed in any of the studies. All supplements had an antibacteri al effect on Cp and improved growth rate significantly. Carcass yield of bi rds fed growth promoters avilamycin or avoparcin was significantly higher c ompared with birds fed anticoccidials. These data indicate that, what conce rns bird performance, during good hygienic conditions supplementation with antibiotic growth promoters may not be necessary when the diet is supplemen ted with an anticoccidial with antibacterial effects.