Brewer's yeast derived functional feed additives to alleviate enteritis in Atlantic salmon
Historically, aquafeeds – fish meal – have been rich in wild sources of marine protein. However, fish meal cannot supply the demand for the growing aquaculture industry and this has seen a major drive to use high levels of plant proteins as feed.
Whilst this is a more sustainable approach, many plant-derived raw materials can cause intestinal inflammation in fishes (enteritis) as they contain anti-nutritional factors (ANFs) such as alkaloids, saponins, gossypol, lectins and fibres.
This intestinal inflammatory pathology is characterised by changes in absorptive cells, elevated pro-inflammatory cytokine production, endocytic blocking, apoptosis, disruption of microvilli and dysbiosis.
Ultimately, this reduces welfare and growth and increases the chance of disease.
Atlantic salmon are particularly vulnerable to the antinutritional factors present in soybean meal which can manifest in an intestinal inflammatory response, known as soybean meal induced enteritis (SBMIE).
Using an Atlantic salmon SBMIE model we are testing the efficacy, and elucidating the modes of action, of brewer's yeast derived functional feed additives rich in MOS, β-glucans, nucleotides and other bioactive compounds to prevent or treat this pathology. Our findings indicate that SBMIE an be alleviated with the application of dietary brewer's yeast products.
