Interactive effects of crystalline amino acids supplemented and diets with different protein quality on performance, energy and protein efficiency, carcass components and intestinal morphology of broiler chickens

For evaluation the effects of different levels of crystalline amino acids supplemented in the diets with different protein quality on performance, energy and protein efficiency, carcass components and intestinal morphology, where, experiment conducted with completely randomized design by 2×4 factorial. In this experiment were used 576 Ross 308 (mixed) broiler chickens with 6 replicates (12 chickens per each replicate) on starter, grower and finisher periods. Experiment diets have been including maize-soybean meal (as high quality protein source) and wheat-canola meal (as low quality protein source) and four levels of crystalline amino acids (recommended levels, 0 or without supplemented crystalline amino acids, 10 and 15% higher than the recommended levels of DL-Methionine, L-Lysine, L-Threonine and L-Tryptophan) by broiler Ross 308. The results of this study showed that the use of adjusted diet based on soybean meal and the recommended level related to other treatments, were causes to increase the energy and protein consumed and also the feed intake and body weight at finisher period. On the other hand, the results showed that adding amino acids crystalline 10 and 15% higher than the recommended levels to diet containing canola meal and wheat as a low-quality source caused an increase on energy and protein consumption, thus reduced energy and protein efficiency and an increase on feed intake and weight gain at finisher period. Interactions between diets with different protein quality and different levels of crystalline amino acids also did not show significant differences on carcass components and intestinal morphological traits.