Evaluation of Dietary Soy Sensitivity in Snake River Cutthroat Trout. (24th March 2015)

• Record Type: Journal Article
• Authors: Ham, Brian R.; Barrows, Frederic T.; Huttinger, Amberly; Duff, Glenn C.; Yeoman, Carl J.; Maskill, Mark G.; Sealey, Wendy M.
• Is Part Of: North American journal of aquaculture. Volume 77:Number 2(2015)
• Page Start: 195
• Page End: 205
• Publication Date: 2015-03-24
• Subjects: Aquaculture -- Periodicals; Fish culture -- Periodicals; Fishes -- Physiology -- Periodicals; Electronic journals; 639.80973
• DOI: 10.1080/15222055.2014.993489
• Languages: English
• ISSNs: 1522-2055

Abstract

Abstract: The shift in commercial diet formulations for Rainbow Trout Oncorhynchus mykiss toward formulations that include more plant ingredients, specifically an increased inclusion of soy products, may have negative implications for less‐domesticated trout species fed these modern diets. Therefore, the objective of this study was to examine the effects of increasing dietary soybean meal and soy protein concentrate inclusion on growth efficiency and intestinal health of Cutthroat Trout O. clarkii . To achieve this objective, a feeding trial was conducted with juvenile Snake River Cutthroat Trout O. clarkii behnkei fed a practical type formulation that included 0, 5, 10, 15, or 30% dietary soybean meal or soy protein concentrate. Feed and consumption, weight gain, proximate composition, intestinal health, and survival were compared. Juvenile Snake River Cutthroat Trout (initial weight, 28.1 ± 1.0 g/fish [mean ± SD]) were stocked at 20 fish per tank in 200‐L tanks with three replicate tanks per diet. Fish were fed their respective diets for 10 weeks. Final fish weight was affected by dietary soy inclusion level ( P = 0.0001) but not type ( P = 0.7790), and no interaction was observed ( P = 0.6019). Snake River Cutthroat Trout fed the diets with the highest level of soy protein inclusion (30%) were significantly larger than fish fed all other diets and had a final average fish weight of greater than 130 g ( P = 0.0001). Feed conversion ratios were higher in fish fed diets with 0% and 5% soy inclusion than in fish fed the 10% or 30% soy inclusion diets ( P = 0.0044). No significant effect of soy inclusion level ( P = 0.0825) on feed intake was observed. Increased inflammation and decreased vacuolization, however, was observed in histological samples of the intestine of Cutthroat Trout fed the 30% soybean meal and soy protein concentrate diets. Additional research is necessary to determine whether the intestinal pathology observed can predispose Cutthroat Trout to pathogenic disease and/or negatively affect growth with extended feeding.