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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVING THE SUSTAINABILITY OF LAND-BASED CLOSED-CONTAINMENT SYSTEMS FOR SALMONID FOOD FISH PRODUCTION

Location: Cool and Cold Water Aquaculture Research

Title: Growth performance, fillet quality, and reproductive maturity of rainbow trout (Oncorhynchus mykiss) cultured to 5 kilograms within freshwater recirculating systems

Authors
item Davidson, John -
item Kenney, P. Brett -
item Manor, Meghan -
item Good, Christopher -
item Weber, Gregory
item Aussanasuwannaku, Aunchalee -
item Turk, P -
item Welsh, C -
item Summerfelt, Steven -

Submitted to: Journal of Aquaculture Research and Development
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 11, 2014
Publication Date: June 28, 2014
Citation: Davidson, J., Kenney, P., Manor, M.L., Good, C.M., Weber, G.M., Aussanasuwannaku, A., Turk, P.J., Welsh, C., Summerfelt, S.T. 2014. Growth performance, fillet quality, and reproductive maturity of rainbow trout (Oncorhynchus mykiss) cultured to 5 kilograms within freshwater recirculating systems. Journal of Aquaculture Research and Development. 5(4): DOI: 10.4172/2155-9546.1000238.

Interpretive Summary: Rainbow trout are commonly cultured within aquaculture systems to one pound or less and marketed as pan-sized fillets. Production of larger rainbow trout provides a distinguishable product. Research that describes the growth performance and fillet quality of large rainbow trout is limited, particularly for trout cultured in environmentally friendly recirculating aquaculture systems. We evaluated the growth performance and fillet quality attributes of all-female rainbow trout reared using freshwater recirculating systems under constant lighting and with around-the-clock feeding. Rainbow trout grew to 4.8 kg or 10.5 lbs in 22 months post-hatch. Although growth rates declined with the onset of reproductive maturity, the trout still reached 5.2 kg or 11.5 lbs at 26 months. Changes in fillet quality coincided with reduced growth rates. Fillet yield peaked at 20-22 months when trout were 3.8-4.8 kg. Cook yield, cooked fillet firmness, and crude fat decreased; while fillet moisture and raw fillet firmness increased from 24-26 months. This research provides rainbow trout growth performance and fillet quality results that can be referenced for the development of recirculating system production plans and for selection of harvest endpoints that balance the requirements of fish farmers and the food industry sector.

Technical Abstract: Rainbow trout are commonly cultured within aquaculture systems to one pound or less and marketed as pan-sized fillets. Production of larger rainbow trout provides a distinguishable product. Research that describes the growth performance and fillet quality of large rainbow trout is limited, particularly for trout cultured in recirculating aquaculture systems. A study was conducted evaluating the growth performance and fillet quality attributes of all-female rainbow trout reared using freshwater recirculating systems operated at a mean water temperature of 13 oC, under constant lighting, and with around-the-clock feeding. Rainbow trout grew to 4.8 kg in 22 months post-hatch. Growth rates declined with the onset of reproductive maturity. Rainbow trout weighed 5.2 kg at 26 months. The mean ratio of feed provided to biomass gain was 1.36:1 from first feeding to 22 months but increased substantially from 23-25 months. As rainbow trout approached reproductive maturity, 10 fish were collected at specified intervals for assessment of fillet quality attributes. Fillet yield peaked at 20-22 months when trout were 3.8-4.8 kg. Cook yield, cooked fillet firmness, and crude fat decreased; while fillet moisture and raw fillet firmness increased from 24-26 months. Changes in fillet quality coincided with reduced growth rates, decreased feed efficiency, and increasing gonadosomatic index. Two principal components were identified that explained more than 73% of the variation in growth and fillet attribute responses: principal component 1, the growth variable (length, weight, fillet thickness, belly flap thickness, and cook yield) and principal component 2, the quality variable (fillet moisture, fillet fat, and cooked fillet firmness). This research provides rainbow trout growth performance and fillet quality results that can be referenced for the development of recirculating system production plans and for selection of harvest endpoints that balance the requirements of fish farmers and the food industry sector.

Last Modified: 10/25/2014
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