Evaluation of the environmental impact of two types of food in intensive farming of rainbow trout fry (Onchoryncus mykiss. Walbaum, 1792).

Abstract The environmental impact of two types of food distributed during the first phase of intensive breeding of rainbow trout (Oncorhynchus mykiss) fry at the station of the National Center for Hydrobiology and Pisciculture constitutes the main objective of this study. the method used for the evaluation of the impact of these two foods is the mass balance method based on the calculation of the quantities of nitrogen and phosphorus excreted according to the quantities of food ingested and the composition of the carcasses. The results obtained show that the weight growth of fry and the rate of nitrogen and phosphorus rejection during the experimental period are very different and vary depending on the type of food received.