Efficacy of neomycin sulfate water medication on the control of mortality associated with colibacillosis in growing turkeys

Abstract

The objective of this investigation was to evaluate the efficacy, safety, and toxicity of neomycin sulfate (Neomix® 325) water medication to control mortality associated with colibacillosis (Escherichia coli) in growing turkeys. One efficacy trial was conducted at five locations; each location included 2,880 sexed 21-d-old turkey poults that were naturally challenged with litter from turkey flocks that had colibacillosis. Between 5 and 7 d after challenge, and when mortality had reached 0.5%, poults were randomized within sex into three treatment groups of 0, 11, or 22 mg neomycin sulfate/kg body weight. In each location, each treatment was replicated 12 times with 40 poults per sex per replicate. All treatments were administered in the drinking water for 5 d. The pivotal decision criterion was mortality. Mortality was defined as 1) supported mortality (SM): positive microbial culture for E. coli and gross lesions, 2) diagnosed mortality (DM): diagnosed as associated with E. coli but not supported by lesions or positive microbiological cultures, 3) overall mortality (OM): mortality associated with E. coli or other microorganisms and miscellaneous reasons such as accidents (trampling or suffocations). Performance data (growth and feed utilization) also were measured and are reported without statistical analysis. Results from this efficacy study clearly demonstrated the effectiveness of neomycin sulfate against E. coli as measured by a reduction in mortality. In the target animal safety and toxicity study (done in conjunction with the efficacy study), neomycin sulfate in the drinking water at 66, 110, or 220 mg/kg per d for 15 d had no observable adverse effects on poult performance, as measured by feed or water consumption, body weight, gross pathology, or mortality.