Effect of booster vaccination with a multivalent clostridial bacterin-toxoid on sudden death syndrome mortality rate among feedlot cattle

Abstract

Objective - To determine whether booster vaccination with a multivalent clostridial bacterin-toxoid would affect the sudden death syndrome (SDS) mortality rate among feedlot cattle. Design - Field trial. Animals - 83,115 cattle at a Nebraska feedlot. Procedure - Cattle arriving at the feedlot underwent routine processing according to established protocol. All cattle received a sequentially numbered ear tag and a 2-ml dose of a multivalent bacterin-toxoid designed to protect cattle against Clostridium chauvoei, C septicum, C novyi, C sordellii, and C perfringens types C and D. Approximately 90 days prior to slaughter, growth promotants were implanted in all cattle, and cattle were allocated to a treatment or control group on the basis of the last digits of their ear tag numbers. Cattle in the treatment group received a second 2-ml dose of clostridial bacterin-toxoid; control cattle did not. Results - Significant differences between groups in regard to crude, feeding pen, or SDS mortality rates were not detected. Sudden death syndrome mortality rate across both groups was 0.24%. If the SDS mortality rate in midwestern feedlot cattle was reduced ≥ 40% by booster vaccination with a multivalent clostridial bacterin-toxoid, this experiment included enough animals to have a 90% probability of detecting that difference. Clinical Implications - Booster vaccination with a multivalent clostridial bacterin-toxoid does not affect SDS mortality rate among feedlot cattle.