An improved method of diet preparation for toxicological feeding experiments

Groups of 30 rats each were fed 1 of 4 diets to determine feeding preference for freeze-dried meal compared to dry meal, and to determine if 3% agar is a desirable component of freeze-dried meal. The diets were: dry meal, meal + distilled water(freeze-dried), meal + 3% agar in distilled water(freeze-dried), and meal + 3% agar in distilled water(gel). Diet preparation, and the method for introducing a toxin in a toxicological study, is described. Feed consumption, bodyweight, and observational data were collected. Rats ate freeze-dried meal in amounts comparable to dry meal. There were no significant variations in feed conversion ratios among the dietary treatment groups. Agar is not required for freeze-dried diets, and we recommend that it be omitted to save resources and preparation time. Freeze-dried diets have a longer storage and cage life, thus the frequency of diet preparation, animal feeding and clean-up are reduced. For studies involving a toxin, these factors would reduce the potential for accidental exposure of personnel to potentially harmful materials.