EFFECTS OF THIAMINE INHIBITORS ON CELLULOSE DIGESTION AND VOLATILE FATTY ACID PRODUCTION IN ARTIFICIAL RUMEN FERMENTATIONS

Abstract

The effect of the inclusion of thiamine inhibitors in a rumen fermentation medium on cellulose digestion and volatile fatty acid production by rumen microorganisms in vitro was studied. The addition of the structural analogues oxythiamine and neopyrithiamine to the fermentation medium at concentrations up to 4000 μM and 2000 μM, respectively, did not influence cellulose digestion or volatile fatty acid production. The addition of thiopental and hexetidine to the fermentation medium affected both cellulose digestion and volatile fatty acid production. Some inhibition of cellulose digestion and of volatile fatty acid production occurred with concentrations of thiopental and hexetidine in the fermentation medium as low as 720 μM and 15 μM respectively.