Nutritional implications of exogenous proteases in fish feeding

The increase in demand for fish production drives the search for food strategies to maximize productivity. In this review, the nutritional implications of the use of exogenous proteases on fish growth were described. Exogenous proteases help in digestive processes, acting in the hydrolysis of macromolecules and in the release of smaller particles, such as amino acids and peptides. Dietary supplementation improves fish growth, mainly due to the availability and greater use of nutrients. The action of proteases is directly linked to better intake, feed efficiency and protein synthesis. On the other hand, enzyme activity depends on substrate and dietary composition as there are limitations on digestibility. Furthermore, in feed processing, thermal stability and the form of inclusion of the protease influence its efficiency. However, the increase in fish weight gain can offset the cost of including the enzyme in the diet. However, there are still gaps regarding the effects of protease in fish feeding, for example, enzyme: specific substrate and enzyme: digestive system ratio; and, stabilization technologies (mainly extruded diets), so further studies are needed.