Food and water intake as functions of resource consumption costs in a closed economy.

摘要: In two experiments, rats living in a closed economy were offered continuous, concurrent access to four resources: food, water, nest, and running wheel. Costs of consuming food water imposed with bar-press requirements, the price either one or both resources was raised. As consumption cost increased, less consumed each bout resource use. Bout frequency but not sufficiently compensate for fall size, total intake fell. Food tended be complementary resources, that as fell its price, other also decreased. This interaction accounted by defense ratio body lean mass. amount decreased, increases feed efficiency (weight gain per unit ingested) use stored calories compensated reduced energy intake. There evidence competition between feeding drinking at higher costs: When commodities expensive, decline greater than when only commodity expensive. Although time spent nesting, running, unmonitored activity adjusted took more rat's day, there no particular sacrificed.