Epsilon Archive for Student Projects

Abstract

Yeast and Clostridia is a problem in silage for farmers as contaminated silage may result in poor animal health and milk quality. Clostridia can produce toxins that, when consumed, acts as neurotoxins, it may also cause blown cheeses if the Clostridia contaminates milk. The purpose of this study was to investigate the cause, effect and interaction of yeasts and Clostridia in silage. Clostridia are microorganisms which are strictly anaerobic and consume carbohydrates and protein in the silage. Yeast is a fungus that is facultative aerobic and feed on carbohydrates in the silage. The reason that yeast and Clostridia occur in silage is mainly caused by that the pH is not reduced in an anaerobic environment or because an anaerobic environment is not maintained in the silage, due mainly to oxygen ingress and holes in the plastic that provides air access to the silage. Yeast and Clostridia consume carbohydrates and proteins in the silage, which result in losses of nutrients. There is an interaction between yeast and Clostridia although they have completely different ecological niches. The most probable situation is that yeast creates an anaerobic environment for Clostridia when it consumes the oxygen in the silage. Therefore, Clostridia and yeast are usually found on the surface layer of silage where it has been an aerobic environment. There is a need for more studies on how yeast and Clostridia interact in different types of silages.