The objective of this research was to determine the most appropriate formulation of diets for rainbow trout (Oncorhynchus mykiss) at different stages of development, this three diets with the use of the Software Alite, one for each phase were formulated taking into account their nutritional requirements; then testing the food formulated for a period of 4 weeks (28 days) feeding trout of the same species and evaluate the biometric growth: Length Standard Single (LSI), Live Weight Single (PVI) Individual Weight Gain (GPI) and Feed Conversion Rate (ICA). After formulated diets by Alite Software, were processed under the quality characteristics of a commercial extruded pellet type, while experimental ponds were adapted into a fish farm located in the town yalen, Pataz - La Libertad, to evaluate each formulation in triplicate for 4 weeks. For formulation I 100 fingerling rainbow trout in each...