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United States Department of Agriculture

Agricultural Research Service

Research Project: UTILIZING GENETICS AND PHYSIOLOGY FOR ENHANCING COOL AND COLD WATER AQUACULTURE PRODUCTION

Location: Cool and Cold Water Aquaculture Research

Title: Impact of carbon dioxide level, water velocity, strain, and feeding regimen on growth and fillet attributes of cultured rainbow trout (Oncorhynchus mykiss)

Authors
item Hafs, A -
item Mazik, P -
item Kenney, P -
item Silverstein, Jeff

Submitted to: Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 16, 2012
Publication Date: April 24, 2012
Citation: Hafs, A.W., Mazik, P.M., Kenney, P.B., Silverstein, J. 2012. Impact of carbon dioxide level, water velocity, strain, and feeding regimen on growth and fillet attributes of cultured rainbow trout (Oncorhynchus mykiss). Aquaculture. 350-353:46-53.

Interpretive Summary: Production and management variables such as carbon dioxide (CO2) level, water velocity, and feeding frequency influence the growth and fillet attributes of rainbow trout (Oncorhynchus mykiss), as well as cost of production. More information is needed to determine the contributions of these variables to growth and fillet attributes to find the right balance between input costs and fish performance. The effects of CO2 level, water velocity, and feed frequency on rainbow trout growth, fillet yield, and fillet quality were determined. Negative impacts of high CO2 levels were observed while low CO2 levels resulted in larger fish and larger fillet weights. In addition, low CO2 resulted in higher percent fat content of the fillets. Fish were also larger and had more fillet fat when fed three times per day compared to once daily. Water velocity had little affects on whole wet weight or fillet attributes. To maximize rainbow trout growth at aquaculture facilities, management strategies should attempt to keep CO2 levels below 30 mg/L.

Technical Abstract: Production and management variables such as carbon dioxide (CO2) level, water velocity, and feeding frequency influence the growth and fillet attributes of rainbow trout (Oncorhynchus mykiss), as well as cost of production. More information is needed to determine the contributions of these variables to growth and fillet attributes to find the right balance between input costs and fish performance. Two studies, of 84 and 90 days duration, were conducted to determine the effects of CO2 level, water velocity, and feed frequency on rainbow trout growth, fillet yield, and fillet quality. In the first study, two CO2 levels (30 and 49 mg/L) and two velocity levels (0.5 and 2.0 body lengths/s) were tested. In the second study two CO2 levels (30 and 49 mg/L) and two feeding regimens (fed once daily to satiation or three times daily to satiation) were tested. In the first study, after 84 days, fillet weight from high CO2 tanks was 13.5% lower than the fillet weights of fish from low CO2 tanks. Percent fat of fillets was higher in low CO2 fish (P = 0.05) after 84 days and, fish from the low CO2 treatment were larger (P < 0.01). Both studies had similar results in regards to fat content and weight of fillets in response to elevated CO2 levels. Velocity had little affect on either whole wet weight or fillet attributes of rainbow trout in this study. Muscle tissue contained more (P < 0.01) fat when fish were fed three times daily (7.3%; day 90) compared to once daily (5.4%; day 90). Also, fish were larger (P < 0.05) when fed 3 times per day (1079 g; day 90) in comparison to only one daily feeding (792 g; day 90). Fish in high feed/high CO2 tanks were larger and had more fillet fat than fish from low feed/low CO2 tanks. To maximize rainbow trout growth at aquaculture facilities, management strategies should attempt to keep CO2 levels below 30 mg/L

Last Modified: 9/20/2014
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