The objective of this work was to evaluate (under field conditions), the performance of bullfrog tadpoles (Rana catesbeiana) raised on commercial frog farms using the "Amphifarm" Systems, and, at the same time, to estimate daily food intake, in order to obtain a reference table for feeding the animals. The results found on the observation units (approximately 249 mil animals) showed the following indexes: mortality(%): range from 0.7 to 35.2, the average being 5.9; weight gain (g/day) varied from 0.03 to 0.22, the average being 0.11; feed conversion ranged from 0.92 to 2.75:1, the average being 1.50:1. Compared to previous data, these results indicate a significant improvement in performance indexes, showing that there was a relative gain in productivity due to the improvement of management techniques. The reduction in average feed conversion was caused mostly by adequate use of the reference table, the values of which were confirmed during a follow-up of the observation units. This table allows the calculation of daily food offer, based on tadpole average weight and on estimated intake as a percentage of body weight, for water temperatures varying from 18 to 29 C and body weight ranging from 0.1 to 26 g.
tadpole rearing; performance indexes; bullfrog; frog production; "Amphifarm" system; feeding table
