The objective ofthis study was evaluate the influence of feeding bullfrog tadpoles on commercialfeed containing 28% crude protein (CP), on their digestive enzyme performanceand activities. The experiment lasted 60 days, at the density of one tadpole/Lin boxes containing 30 L water. A hundred and twenty tadpoles at the 25 Gosnerstage averaging weight and length was 0.046 g and 6.22 mm, respectively, wereused. Survival rate, length, final weight, weight gain, feed consumption, apparentfood conversion, specific growth rate and activities of chime, amylase, lipaseand trypisin were the parameters evaluated, biweekly, in five biometries. Quadraticeffect was observed for the length and the weight. There was larger growth ofthe tadpoles from the 15th to the 45th day (19.82 mm).On the 15th day, the tadpoles presented the largest specific growthrate (16.93%/day), and the largest weight gain (5.460 g), feed intake (14.099g) and the best apparent food conversion (2.46) was from the 45thto the 60th day. The specific activity of amylase was 205 times greaterat 60 days when compared to the beginning of the experiment. The results demonstratedthat, for the three enzymes studied, the action capacity over the tadpole chimeincreased significantly after the 30th experimental day. Moreover,they suggested a greater capacity of tadpoles to digest carbohydrates in detrimentto proteins, and this fact was accentuated in the initial phase of the exogenousfeeding of this amphibian. The commercial feed with 28% CP provide good performancein the bullfrog tadpoles, indicating the juvenile formation within commercialbullfrog farming standards.
