Effects of Antarctic Krill Products on Feed Intake, Growth Performance, Fillet Quality, and Health in Salmonids

Abstract

The interest for krill-based ingredients for aquaculture feed applications has increased steadily in recent years. For decades, there has been a heavy reliance on the limited sources of fishmeal and fish oil in the salmonid aquaculture industry. Further growth in farming of carnivorous fish is dependent on new feed resources becoming available. The only unexploited marine resources of significant biomass are found at lower trophic levels, of which the Antarctic krill (Euphausia superba) has a high potential. Apart from being the biggest single species biomass, Antarctic krill is also rich in nutrients, such as omega-3 polyunsaturated fatty acids, phospholipids, astaxanthin, vitamins, and minerals. This makes Antarctic krill a high-quality source of health-beneficial lipids and proteins. The present article provides an overview on the documented benefits of feeding salmonids (Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss)) with krill products (krill meal, krill oil, and krill hydrolysate), focusing on growth performance (feed intake, growth rate, and feed conversion), fillet quality, slaughter yield, and health benefits in terms of reducing fat accumulation in liver and intestinal tissues. Besides, the article discusses possible future studies, to widen the knowledge on krill benefits in salmonids and to unravel the underlying mechanisms.