Four hundred and eighty broilers were assigned to a completely randomized design with a 6x2 arrangement (six levels of manganese and 2 sexes - male and female) and four replicates to determine the manganese requirements in the growing (22 to 42 days) and finishing (43 to 54 days) phases. Six and four birds per experimental unit, respectively, were used in the first and second trials. In both trials, the treatments consisted of a basal diet deficient in manganese (6.5 ppm) or supplemented with manganese (0, 30, 60, 90, 120, and 150 ppm) from the commercial sulfate. The following variables were analyzed: weight gain, feed intake, feed conversion, tibia length, resistance of bone to breaking, and manganese concentration in the liver and bone. The levels of manganese influenced the manganese concentration in the liver and bone in the growing phase and the manganese concentration in the liver in the finishing phase. The manganese requirements were estimated by the polynomial regression models and LRP (Linear Response Plaeau). The manganese requirement was estimated in 90 ppm for male and female broilers in the growing phase. In the finishing phase, the levels from 30 to 40 ppm of manganese is recommended to obtain good results of performance for birds fed corn and soybean meal-based diets.
performance; mineral; manganese; chicken; bone
