A NOTE ON THE ECONOMIC EFFECT OF THE UTILIZATION OF AMINO-ACIDS IN BROILER RATIONS

Thirty variants of a basal diet containing as main raw materials: maiz e meal, soybean meal, torula yeast and fish meal, were studied. They w ere formulated through linear programming with a fixed protein level f or the starting and finishing stages of 23 and 19.5%, respectively or where the protein level was not fixed (open protein), but the amino ac id requirements (methionine + cystine, lysin, tryptophane and threonin e) were covered, for studying the performance of the production costs/ t of these diets to select the most advantageous from the economical p oint of view and at the same time the one contributing to the demanded requirement for each stage. It was evidenced that when the protein le vel was not previously fixed, the production cost was reduced by 42.84 and 49.74 Cuban pesos/t for the starting ana finishing stages, respec tively, which also allows to decrease the CP percentage used in both s tages. It is concluded that for ration formulation with open protein, then is no need to consider CP as a restriction however the amino acid s methionine-cystine and lysin must be taken into account for the star tingand finishing stages, since the requirement guarantees that the re st of the amino acids will be covered. Further studies are needed to c onfirm both liveweight gain and feed conversion of broilers for analys ing their economic viability.