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

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 speticum, 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 bacterintoxoid; 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 > or = 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.