Immunisation Against Lactic Acidosis in Sheep and Cattle

Abstract

Introduction: Lactic acidosis is due to the over production of lactic acid in the rumen by the bacteria, 'S. bovis' or a combination of 'S. bovis' and 'Lactobacillus' when sheep and cattle consume large amounts of grain. It was hypothesised that the risk of lactic acidosis could be reduced by immunisation against the lactic acid producing bacteria. The present studies were conducted to test this hypothesis and investigate several key factors for developing an immunisation strategy against lactic acidosis. ... General discussion: Results from the studies in sheep and cattle support the hypothesis that the risk of lactic acidosis can be reduced by immunisation against 'S. bovis' or 'S. bovis' and 'Lactobacillus'. Live vaccine (using DEAE-dextran combined with mineral oil as an adjuvant) may provide a suitable protection using one booster following a primary immunization administered intramuscularly. This novel approach to reducing the risk of lactic acidosis associated with grain feeding offers a promising alternative to current practices of using feed additives, such as antibiotics active against the lactic acid-producing bacteria.