Joao Batista Kochenborger Fernandes
Specialized Fish Technicia, Aquaculture Center of UNESP, Brazil
Title: Deletion method to establishing the optimal essential amino acid ratio for juveniles of pacu (Piaractus mesopotamicus)
Biography
Biography: Joao Batista Kochenborger Fernandes
Abstract
The aquaculture look for more and more an efficient production, less environmental impact and increased profitability. Knowing that the correct feeding and balanced diet promotes maximization of growth and health, reduce the production costs and water pollution, the present study aimed to estimate the essential amino acids (EAA) ratio for juveniles of pacu (Piaractus mesopotamicus) using the deletion method. For this, 635 pacus (6.23g) were distributed in thirty three tanks connected to a closed water recirculation system equipped with filter, water heater (27.8ºC) and aeration. The experiment lasted 113 days and consisted of 11 experimental diets with three replications each, distributed in a completely randomized design. The fishes were fed twice a day until apparent satiation. The semi-purified and extruded diets were formulated by the deletion technique, where the control diet presented all the EAA in a balanced way, while the experimental diets presented the deletion of 45% of the respective tested EAA. In this way it was possible to obtain 11 isonutrient diets varying only the tested EAA. The determination of the essential amino acids ratio was performed by the ratio between the nitrogen retention in fish body and the amount of the EAA deleted in the tested diet. Thus, assuming that each EAA is equally limiting, our results show the ideal dietary EAA profile relative to lysine was estimate to be: lysine 1.000, arginine 0.593, threonine 0.336, valine 0.282, leucine 0.396, isoleucine 0.220, phenylalanine 0.226, methionine 0.126, tryptophan 0.063.