Zootechnical performance of bullfrog tadpoles under different levels of digestible protein and energy

Abstract

From the digestibility values of some ingredients, it was proposed diets with different levels of digestible protein and energy, in a 3x3 factorial design for bullfrog tadpoles, aiming at evaluate the zootechnical performance. The experiment was conducted during 60 days with 810 tadpoles from the same spawning distributed into 27 polypropylene boxes at a density of 1 tadpole/L. The experimental design consisted of a factorial arrangement with three levels of digestible protein (27; 31 and 35%) and three levels of digestible energy (2700; 2800 and 2900kcal/kg) with three repetitions. Parameters evaluated at 60 days were weight gain, feed intake, dietary protein intake, feed conversion, protein efficiency rate and survival rate. Results were subjected to analysis of variance and Duncan test (95% accuracy), and presented no interaction between digestible protein and digestible energy for any parameter evaluated. As for the digestible protein, significant differences were detected in the dietary protein intake, and protein efficiency rate, evidencing inefficiency of diets with high protein values. Bullfrog tadpoles should be given diets with 27% digestible protein by having the best result for the protein efficiency rate and for the dietary protein intake, with the lowest value and similar to other levels among evaluated parameters.