BLOAT IN CATTLE .32. ATTEMPTS TO PREVENT LEGUME BLOAT IN DRY AND LACTATING COWS BY PARTIAL OR COMPLETE ELIMINATION OF RUMEN HOLOTRICH PROTOZOA WITH DIMETRIDAZOLE

Administration of dimetridazole (1,2-dimethyl-5-nitroimidazole) can reduce or eliminate the population of holotrich protozoa in the rumen and can substantially reduce the incidence and severity of bloat in both stall-fed, non-lactating cows and grazing, lactating cows. Part of the effect in reducing bloat may result from the reduction in rumen ciliate numbers and part may be the result of the temporary reduction in food intake and general inhibitory effect on rumen fennentation which was demonstrated in non-lactating cows. In some cows bloat may still occur after treatment with dimetridazole even though the population of rumen holotrich ciliates has been eliminated. This, combined with a reduction in food intake and milk production, makes dimetridazole of little practical value as a bloat prophylactic. © 1969 Taylor & Francis Group, LLC. All rights reserved.