Effects of ambient temperature, diet quality, and food restriction on body composition dynamics of the prairie vole, Microtus ochrogaster.

We manipulated diet quality, food availability, and ambient temperature to investigate the role of these variables in fat deposition by growing prairie voles (Microtus ochrogaster) and fat use by adult voles. Exposure to either 5 degrees C or a high-fiber diet reduced fat deposition by growing voles and also reduced growth as measured by body length. Adult voles on the high-fiber diet reduced fat content, but exposure to 5 degrees C had no effect on body composition. Both the high-fiber diet and exposure to 5 degrees C caused increased food intake and reduced diet digestibility for adult voles. Restricting access to food resulted in reduced lipid mass of all adult voles and reduced fat-free mass of those held at 5 degrees C. When faced with poor food quality or cold ambient temperature, voles will increase food intake rather than catabolize lipid tissue. When food availability is limited, however, voles will use fat stores to meet the balance of their energy requirements.