Digestible energy versus net energy approaches in feed evaluation for rainbow trout (Oncorhynchus mykiss)

•In rainbow trout, the utilization efficiency of digestible energy for growth is affected by macronutrient composition.•Digestible carbohydrate is utilized to a lesser extent compared to digestible fat in terms of energy efficiency.•Dietary net energy content was superior to digestible energy in predicting the growth performance of rainbow trout.