Fish Oil Sparing and Alternative Lipid Sources in Aquafeeds

Abstract

Nowadays, the culture of aquatic species is mainly fueled by formulated compound diets that, to a large extent, depend on marine-derived feedstuffs, namely fish meal (FM) and fish oil (FO). However, the restricted availability of FO, with regard to aquaculture production needs and its variable price, compromises the progressive growth of the aquaculture industry. Thus, partial or total replacement of dietary FO with cost-effective and environmentally friendly alternative lipid sources (ALS) in aquafeeds is required for sustainable aquaculture production. During the last two decades, a plethora of studies have been focused on evaluating the potential use of different ALS in aquafeeds; in many cases, the replacement of dietary FO with ALS was successful although it depended on the species and culture conditions. However, many studies have also demonstrated negative effects of dietary FO substitution with ALS on performance, fish welfare, and product quality in different aquaculture species. This chapter initially focuses on the several drawbacks with regard to the use of FO in aquafeeds and introduces the principle of ALS. In addition, the effects of partial or total replacement of dietary FO with ALS on growth performance, feed utilization, nutrient digestibility, fatty acids profile, and organoleptic properties of the fillet, the general health and welfare of cultured aquatic species as well as risk assessment in the application of ALS in aquafeeds are systematically reviewed and discussed. The revision of the available literature indicated that FO will not be a limiting factor for the development and continuous increase of the aquaculture industry, since there exist reliable strategies for its replacement. Thus, by applying nutritional strategies for FO sparing in feed formulation by considering the properties of ALS fish species, their essential fatty acid requirements, and their culture condition, the sustainability of aquafeed production will be guaranteed.