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°C, 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 .
Highlights
Recent development and advancements in water recirculating systems for the culture of rainbow trout (Oncorhynchus mykiss) and other salmonids [1,2,3] provide opportunity to expand current production levels
Thermal growth coefficient averaged 2.13 from first feeding to 12 mo (1.4 kg) as fish grew to 1.4 kg, 1.49 as fish grew from 1.44.8 kg (13-22 mo), and 0.30 as fish grew to 5.2 kg (23-26 mo) (Table 2)
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 food industry sectors
Summary
Recent development and advancements in water recirculating systems for the culture of rainbow trout (Oncorhynchus mykiss) and other salmonids [1,2,3] provide opportunity to expand current production levels. Successful rainbow trout culture to approximately 1.3 kg was reported in a Danish model RAS [11]; and previous on-site studies demonstrated that rainbow trout can be cultured within RAS to approximately 1.3-1.4 kg in one year from hatch [2,12,13]. These studies did not attempt to culture trout to larger sizes and evaluation of fillet quality was limited
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
