Food motivation of rehabilitated malnourished rats: Implications for learning studies

Adult male, and female rats that had suffered either postnatal undernutrition or postnatal zinc deficiency were more highly motivated for food than normal rats. A progressive ratio schedule was used to test the rats for food motivation. All rats were deprived of food 24 h prior to testing. Each rat was tested once a week for 8 consecutive weeks. The smaller body size of the previously malnourished rats relative to their body surface area seemed to be the best explanation for their higher level of motivation.