Effects of the Fusarium mycotoxin deoxynivalenol on in vitro rumen fermentation

The objective of this study was to determine the effect of deoxynivalenol (DON) on in vitro rumen fermentation by assessing pH, ammonia-N, total gas, volatile fatty acid (VFA) production, and DON degradation under the context of two different carbon sources (corn starch or cellulose). Fifty millilitre of ruminal fluid:buffer (1:1) was incubated for up to 6 h with four possible treatments: corn starch 1.5 g, corn starch 1.5 g + DON at 40 mg/kg dry matter (DM), cellulose 1.5 g, and cellulose 1.5 g + DON at 40 mg/kg DM. Our results indicate that carbon source appears to markedly influence all rumen fermentative parameters (P<0.05), whereas DON negatively impacted certain aspects of rumen fermentative capacity, such as ammonia-N and total gas production, especially acetate and propionate production having been reduced (P<0.01). Therefore, it may be possible for carbon source to influence and limit the degree upon which DON's effects are exerted. DON degradation rate was especially influenced by carbon source context (P=0.0105) with cellulose leading to a higher rate of DON degradation than that of corn starch. This would indicate that concentrate/forage ratio, in the diet, may have an effect on DON degradation.