Location: Cool and Cold Water Aquaculture ResearchTitle: Growth and fillet quality attributes of five genetic strains of rainbow trout (Oncorhynchus mykiss) reared in a partial water reuse system and harvested at different sizes Author
|Crouse, Curtis - Freshwater Institute|
|Davidson, John - Freshwater Institute|
|Good, Christopher - Freshwater Institute|
|May, Travis - Freshwater Institute|
|Summerfelt, Steven - Freshwater Institute|
|Kenney, P. Brett - West Virginia University|
|Leeds, Timothy - Tim|
Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/4/2018
Publication Date: 1/25/2018
Citation: Crouse, C., Davidson, J., Good, C., May, T., Summerfelt, S., Kenney, P., Leeds, T.D., Cleveland, B.M. 2018. Growth and fillet quality attributes of five genetic strains of rainbow trout (Oncorhynchus mykiss) reared in a partial water reuse system and harvested at different sizes. Aquaculture Research. 49:1672-1681. https://doi.org/10.1111/are.13623. Interpretive Summary: Selection for improved growth is a common goal for salmonid selective breeding programs since faster growth generally means increased profitability. To support this objective, the NCCCWA selective breeding program has been breeding rainbow trout for improved growth (Growth Line) for five generations. Although growth performance of the Growth Line is better than or similar to commercial lines, it is unknown how they fare in terms of fillet quality. This study indicated that, despite substantial variations in growth performance between lines of rainbow trout, fillet quality did not differ in terms of nutrient composition (ie: protein and fat content), flesh texture, or flesh color. However, fillet quality in all rainbow trout lines varied considerably as fish got larger and reached different harvest weights. These findings indicate that if a producer favors rapid growth then selection of the appropriate commercial line is critical. In contrast, if a producer or processor values fillet quality over fast growth, which might occur when targeting a niche market, then selecting the appropriate diet or harvest age is critical since all commercial lines exhibit similar fillet quality characteristics.
Technical Abstract: Genetics and environment can interact to influence fish growth performance and product quality attributes. Interaction in recirculating aquaculture systems (RAS) makes selection of fish strain and harvest sizes critical for optimizing fish quality. Definition of growth performance and quality outcomes may guide selection of fish stocks best suited for RAS to meet production and product quality goals. Accordingly, five genetic lines of rainbow trout, Oncorhynchus mykiss were reared to 3kg in a partial water reuse system and sampled at common harvest sizes (0.5kg, 1kg, 2kg, and 3kg) to compare growth performance and product quality attributes. Genetic line affected fish weight (p = 0.05) at each harvest, although muscle composition and texture was similar between genetic lines. Differences in somatic indices and processing yields were observed between genetic lines, however, this was attributed to aforementioned differences in fish weight opposed to direct result of genetic line. Fillet a* values (red color space measurement) increased in response to a pigmented diet. Demonstrating differences in growth performance and product quality traits due to genetic variation will determine if fish stocks are available to meet individual production interests, and quantifying change to these traits over time can guide selection of optimal harvest size.