Digestible protein requirement for Nile tilapia fed with rations based on soybean meal and corn

ABSTRACT. The objective was to determine the requirement of digestible protein (DP) for Nile tilapia fed with diets based on soybean meal and corn. Two hundred Nile tilapia juveniles, sexually reversed, were used for a trial period of 100 days. The animals were distributed in 20 boxes of 1000 L-1 in a random design with five treatments and four replications, the boxes were connected to a water recirculation system. Five isoenergetic diets were tested with different levels of digestible protein (DP): 20, 25, 30, 35 and 40%. At the end of the experimental period were evaluated the zootechnical performance data. A quadratic effect (p