DEGRADATION OF L-5-VINYLOXAZOLIDINE-2-THIONE, A GOITROGENIC PRODUCT FROM RAPESEED, BY RUMEN MICROORGANISMS

The use of rapeseed meal for animal feeding is limited by the presence of antinutritional compounds, such as glucosinolates. An in vitro rumen system was used to test the effect of L-5-vinyloxazolidine-2-thione (VOT), a toxic hydrolysis product from glucosinolates found in rapeseed. The effect of VOT on rumen performance was minimal. The VOT was degraded efficiently (60-70%) in the artificial rumen system, when rapeseed was fed batchwise at 20% (w/w) of the diet. The degradation of VOT is caused by bacteria because the addition of the (oil containing) rapeseed resulted in a disappearance of ciliated protozoa. Experiments with pure VOT resulted in complete degradation both in batch (2 mM) and in continuous culture (4 mM).