Influence of temperature and air flow in the food intake and weigth gain in Wistar rats (Rattus norvegicus) kept on microenvironmental system for laboratory animals

Abstract

Wistar rats had been kept individually, in metabolic wire cages, without shelter, in microenvironmental system, under direct air flow at 0,6 m/s, under temperatures of 22º, 24º, 26º, 28º and 30º C. The food consumption and the weight gain had been compared in the end of 5 days (ANOVA; Tukey-Kramer). In the total, 7 groups, 10 animals each, had been compared. For the 22ºC temperature, had been used 3 groups, one experimental and two controls. One of them was kept in similar ambient of conventional laboratory animal rooms conditions (general diluitory ventilation, GDV) - C1. The other control group (C2) was kept in the interior of the equipment of microenvironmental ventilation, however, without the direct air flow, simulating the GDV. The gotten results demonstrate clearly that animal kept under direct microenvironmental ventilation at 26º, 28º and 30ºC have the same gain of corporal mass that C1 group. The groups kept at 22º and 24ºC, had less corporal mass gain when compared to C1 (p<0,001 and p<0,01 respectively). The weight gain for all the experimental groups, when compared to C2, presents statistical differences, except 30ºC group, that was equal to C2. The food consumption of all the groups was constant. Only the 30ºC group presented a reduction in the food consumption when compared with the groups C1 and C2 (p<0,05 for the two comparisons).