This Is AuburnElectronic Theses and Dissertations

The effects of dietary inclusion of a Saccharomyces cerevisiae fermentation product in a commercial catfish ration on growth, immune readiness, and columnaris disease susceptibility




Brown, Taylor

Type of Degree

Master's Thesis


Fisheries and Allied Aquacultures


Aquaculture is the fastest growing sector of animal agriculture. However, sustainable expansion and intensification of aquaculture worldwide has been severely hampered by disease. In the US catfish industry, the largest segment of US aquaculture, disease-based mortality levels can reach nearly 60% over the course of a production cycle. Columnaris disease, caused by Flavobacterium columnare, represents one of the largest sources of mortality in the industry. Despite its importance, there are currently few effective weapons available to combat this debilitating pathogen. Catfish producers are eager to gain protection against columnaris and other diseases in a more natural and cost-effective manner, i.e. through diets supplemented to provide for both mucosal health and performance. Here, we evaluated a Saccharomyces cerevisiae fermentation product (Diamond V Original XPC™). The trial featured four levels of inclusion which were added to a commercial 32% protein floating catfish ration. Following six weeks of feeding, we observed heightened resistance to columnaris disease and saw significant changes in the levels of immune effectors in the serum including lysozyme, complement, and immunoglobulin. Our results stress the importance of understanding and prioritizing the protective benefits of dietary ingredients for aquaculture species alongside more typical consideration of a species’ minimal nutritional requirements.