José Milton Barbosa

Crescimento heterogêneo de girinos de rã-touro alimentados com diferentes rações

This work tested the performance and growth variability (heterogeneous growth) of Rana catesbeiana tadpoles fed with isocaloric food constituted of four levels of crude protein: three experimental levels (33.6%, 26.6% and 22.5%), and one commercial feed (46.5%). The tadpoles were kept, during three months, in containers with capacity for 1,000 L supplied with running water at density of one tadpole L-1. The tadpoles were fed twice a day with ad libitum portions, and submitted to the body weight records every fifteen days. The group fed with commercial food (46.5% crude protein) showed better biomassa performance, however the heterogeneous growth was elevated, with body members deformations in some individuals (27% of tadpoles of the total tadpole-initiated metamorphosis, and 5% at the end). Tadpoles fed with 33.6% and 26.6% of crude protein had similar growth, less heterogeneous growth and did not show body deformations, indicating that these protein concentration might be more adequate than the commercial one. Food with 22.5% of crude protein showed to be inadequate for the nutritional needing of the tadpoles, so it was excluded from the experiment, in order to preserve the animals from injury and death.