Content area
Full text
Background
In the period 2000-2012 the world food fish aquaculture production expanded at a rate of 6.2% per year [1]. This trend is expected to continue as the demand for fish products will increase, following the raise of the world population expected by 2050. Fishmeal (FM) is considered as the optimal protein source in fish feeds. However, the availability of wild harvested marine fish stocks for FM production is decreasing and conventionally used proteins have been claimed to be no longer sustainable from both economic and ecologic points of view [1]. For these reasons, research has actively worked to deliver fish feed formulations containing alternative protein sources. The most commonly used ones are plant protein sources (such as oilseed meals, cereal proteins and grain legumes) and Processed Animal Proteins (PAPs) derived from animal by-products (poultry meal, hydrolyzed poultry feathers, blood meal). As far as the former are concerned, some adverse effects on performances or intestinal integrity have been reported [2, 3] even if technological advances in plant raw material processing and the increased knowledge on fish requirements have allowed the formulation of fish feeds mainly based on plant proteins [3]. PAPs provide good quantities of essential amino acids even if methionine, lysine, histidine, isoleucine and tryptophan could be limiting depending on the drying or cooking methodologies followed during manufacturing [4].
Among PAPs, interest is recently turned to insect meals as they are considered promising and sustainable protein [5, 6] or lipid [7] sources for monogastric animals feeds. In a context of resource scarcity and population growth, insect meals could represent a precious alternative to FM in aquaculture feeds [6], also considering that freshwater carnivorous fish eat insects in their natural environment.
Interesting results have already been reported using insect meals as FM substitute in the diets of some fish species [8-13]. Investigations have also been performed as far as sensory aspects [9, 14] and consumer acceptance are concerned [15] with promising results. Nevertheless, potential hurdles have also been highlighted (toxicity of insects through bioaccumulation, deficiencies in amino acids (AA) or long chain fatty acids (FA), chitin content, palatability, digestibility) [6]. To date, the price of insect meals is not yet competitive due to low produced quantities [16]. However, as on December 2016 the EU Commission...