Agri-practice – Cow/calf – Disease Control

At 14-day intervals, 12 calves were vaccinated twice with a S. typhimurium bacterin-toxoid, and 12 control calves each received two injections of dialuminum trioxide/saline placebo. Two weeks following the vaccination booster, or the second placebo injection, ten calves – five vaccinated and five treated with placebo – were challenged with 100 ng/kg of E. coli 055:B5 endotoxin. Similarly, another 14 calves – seven vaccinated and seven placebo-treated – were challenged with 50 ng/kg of P. multocida endotoxin. There was a significant difference (P < 0.05) between the clinical responses of the vaccinated and placebo-treated group challenged with either E. coli 055:B5 or P. multocida endotoxin as measured by the endotoxin colic index, mean anorexia time intervals, and IgG(t) serum antibody titers.