Effects of virginiamycin and salinomycin on performance, digestibility of nutrients and mortality of rabbits

A total of 432 weaned Hyla 2000 rabbits was used to evaluate the effect of virginiamycin (a feed antibiotic), salinomycin (a coccidiostat) and their combination on performance, digestibility of nutrients, blood composition, slaughter parameters, incidence of coccidia and mortality. Virginiamycin and salinomycin were supplied at 30 and 20 mg/kg of a granulated feed, respectively. In a feeding trial, 100 rabbits per treatment were used. From the beginning (day 33–34 of age) to the end (day 86–87), control rabbits gained 31.4 g day−1, on an average. Daily weight gains of rabbits fed virginiamycin, salinomycin and a combination of virginiamycin and salinomycin were 33.8, 33.5 and 35.8 g day−1, respectively (p < 0.05). The combination of feed additives decreased mortality from 12% (control) to 2% (p < 0.001). In a digestibility trial, 32 rabbits were allotted to the same dietary treatments. Virginiamycin significantly decreased digestibility of fibre and increased that of fat. Salinomycin increased concentration of Mg in plasma. There were no important differences in other digestibility and blood variables determined. No significant effects of additives on slaughter parameters (except hindleg and perirenal fat proportions) were found. Salinomycin decreased the incidence and intensity of infection by Eimeria sp. and completely eliminated cryptosporidia.