Use of glycerol in fish nutrition: a review

Abstract

AbstractCrude glycerol and its purified and synthesized forms derived from biodiesel production are non‐toxic, biodegradable, biocompatible and versatile, and can be converted into various chemicals or products for biological use. Among the possible uses, there is its use in fish feeding, due to the chemical and nutritional composition, for being classified as energetic food and has low cost. The possibility of using glycerol in fish diets has been motivated by increasing maize prices, the excessive amount of glycerol produced and its processing costs for other purposes. Glycerol use in fish diet formulations is feasible, provided that certain factors be evaluated, such as digestibility and inclusion levels. In this context, this review discussed the main aspects that must be taken into account regarding glycerol use in fish diets, such as the characteristics and chemical composition of its categories, their fish metabolism pathways and their influence on fish plasma glucose. Crude glycerol or glycerine displays good potential for use in fish feed, as it contains adequate energy concentrations and can replace part of fish feed maize. However, it is evident that assessments concerning specific physiological phases, such as fish in reproductive phases, as well glycerol stability in water, are required.