Effects of environmental conditions on food consumption in female and male rats.

The present experiment examined food and water consumption under different housing conditions in 20 female and 20 male Wistar rats. Food and water consumption were measured for 6 h a day following an 18-h same-sex crowded or individual housing period for each of 6 days. All subjects were individually housed during the 6-h measurement period and had access to food and water. Female rats consumed more food and water than did male rats during the 6-h period, regardless of their 18-h housing condition. In addition, previously crowded rats consumed more food and water during the 6-h period than did rats that were previously individually housed. During the 18-h period, when subjects were differentially housed, males consumed more food and water than did females; crowded rats ate less than did individually housed rats; and crowded rats drank more water than did individually housed rats. Based on plasma corticosterone data, the female and male rats were differentially affected by housing conditions. The present results are discussed with regard to housing conditions per se and sex differences in stress responses to housing.