Their latest study, entitled "Fishmeal and fish oil replacement in feeds for Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss)," examines the use of alternative protein sources, such as plant-based meals, insect meal, and single-cell proteins, in combination with various lipid sources, including vegetable oils, algae oil, and fish oil from trimmings and by-products.
The researchers conducted multiple feeding trials with Atlantic salmon and rainbow trout to assess the growth performance, feed utilization, and fatty acid profiles of fish fed diets with different combinations of alternative feed ingredients. They found that diets with partial or complete replacement of fishmeal and fish oil with sustainable alternative ingredients could maintain the nutritional needs and performance of the farmed fish.
Moreover, the researchers examined the effects of the alternative diets on the sensory characteristics and quality of the farmed fish. Their sensory analyses revealed no significant differences in the flavor or texture of fish fed alternative diets compared to fish fed a traditional fishmeal- and fish oil-based diet.
This study contributes to the growing body of knowledge on sustainable aquaculture feed development and supports the concept of increasing the use of alternative ingredients in aquafeeds to reduce reliance on wild fish resources and promote sustainable growth in the aquaculture industry.
Key findings:
- Complete fishmeal replacement was possible for rainbow trout and nearly complete for Atlantic salmon without negatively impacting growth or nutrient utilization.
- Complete replacement of fish oil reduced growth and lipid retention, but no signs of deficiency-related health issues were observed.
- Some alternative ingredients affected sensory quality parameters of the fish fillets. This includes increased fishy/metallic flavors and darker coloration of fish fed vegetable oils.
- The replacement of fishmeal and fish oil in aquafeed is dependent on the species in question, the feed formulation, and the quality/characteristics of the alternative feed ingredients.
