RELATIVE SENSITIVITY OF REPRODUCTIVE ACTIVITY AND BODY-FAT LEVEL TO FOOD RESTRICTION IN WHITE-FOOTED MICE

Food intakes of only 70-90% of ad lib consumption for 2-3 wk reduced the incidence of estrus and increased the incidence of imperforate vaginae in singly caged, female white-footed mice (P. leucopus). Similar food intakes in pairs of mice reduced their production of young. Conversely, there was not a close relationship between body weight or carcass fat levels and level of food intake. The data show that reproductive activity is more sensitive to minor food restriction than either body weight or carcass fat and illustrate that reproductive characters are better and more sensitive indicators of recent food availability than body weight or fat content.