Use of animal by-products in diets formulated based on crude and ideal protein fed to broiler from 1 to 21 days of age

An experiment was conducted to evaluate the use of animal by-products in broiler diets, formulated based on crude and ideal protein. The experimental design was a completely randomized in a factorial arrangement 2x2+1, with two animal protein sources (poultry viscera meal and bovine blood meal), two formulation concepts (based on crude and ideal protein) and a control diet based on corn and soybean meal, with four replications. The evaluated characteristics were weight gain, feed intake and feed: gain ratio. There was a significant effect of the interaction animal protein source x formulation concepts on feed intake and weight gain. There was not significant effect of the interaction on feed: gain ratio and the best values were found when the poultry viscera meal was added to the diets. The best weight gains were obtained with the diet formulated with bovine blood meal using the crude protein concept and, using the ideal protein concept the best result was obtained when the poultry viscera meal was added to the diets.