Diets containing corn naturally contaminated with deoxynivalenol reduces the susceptibility of rainbow trout (Oncorhynchus mykiss) to experimental Flavobacterium psychrophilum infection |
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| Authors: | Ian A Ryerse Jamie M Hooft Dominique P Bureau M Anthony Hayes John S Lumsden |
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| Institution: | 1. Department of Pathobiology, University of Guelph, Guelph, ON, Canada;2. Department of Animal and Poultry Science, University of Guelph, Guelph, ON, Canada |
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| Abstract: | The objective of this study was to determine if deoxynivalenol (DON) exposure alters the susceptibility of rainbow trout to bacterial coldwater disease caused by Flavobacterium psychrophilum. Rainbow trout were fed a nutritionally complete diet containing corn that was naturally contaminated with DON at a desired concentration of <0.5 (control and pair‐fed treatments), 4 or 6 ppm over 7 weeks to apparent satiation. After 4 weeks, fish were infected by intraperitoneal injection with F. psychrophilum (3.03x106 CFU mL?1) via intraperitoneal injection and monitored for morbidity and mortality. A significant linear reduction in feed intake was associated with increasing dietary levels of DON contamination over the initial 4 weeks. There was a significant reduction (P < 0.05) in cumulative per cent mortality in DON‐fed groups (4.1 ppm, 11%; 5.9 ppm, 7%) in comparison to control (46%) and pair‐fed (25%) groups at 21 days post infection. Mortality of trout pair‐fed the control diet was also significantly lower (P < 0.05) than the control group fed to apparent satiation. A replicate trial using genetically similar fish and the same experimental design produced similar results. These results suggest that DON exposure and restricted feed intake provided a protective effect for rainbow trout infected with F. psychrophilum. |
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| Keywords: | deoxynivalenol rainbow trout corn
Flavobacterium psychrophilum
coldwater disease |
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