Exploring the use of net energy evaluation for salmonids
Currently, feed evaluation for aquaculture in terms of performance is commonly based on digestible energy (DE) values and assumes a fixed utilisation of energy for growth. However, recent literature has made clear that not all forms of this digestible energy are utilised for growth with the same efficiency and is causing inaccuracies in the use of this DE approach. It therefore makes sense to move to a net energy (NE) approach, which is already commonly used in pig feed evaluation and takes into account differences in the forms of digestibly energy (either from protein, fat or carbohydrates).
This project will focus on exploring the potential use of the NE approach in feed evaluation for salmonids in aquaculture. Firstly by looking at the difference in predicting growth performance by DE or by a NE system as proposed by recent literature. Secondly by increasing the strength of such a model by looking more in to the carbohydrate fraction, especially the difference in nutritional value between starch and other non-starch polysaccharides. Finally, this project will examine potential factors influencing NE evaluation. Potential factors being the effect of species (rainbow trout vs Atlantic salmon) and life stage (parr versus smolt) in practical NE evaluation.