RELATIONSHIP BETWEEN FEEDING, STEREOTYPIES, AND PLASMA-GLUCOSE CONCENTRATIONS IN FOOD-RESTRICTED AND RESTRAINED SOWS

Previous work has shown that stereotypies, such as chain manipulation and excessive drinking, only develop in food-restricted sows. Furtherm ore, once stereotypies have been developed, ingestion of a small meal specifically stimulates the performance of stereotypies. These results suggest that the occurrence of stereotypies may strongly depend on th e individual's nutritional status. As glucose is one of the main metab olic fuels, the present experiment investigated whether individual dif ferences and/or daily variations in levels of chain manipulation and e xcessive drinking are correlated to individual differences and/or dail y variations in pre- or postfeeding glucose concentrations. Blood samp les were taken at regular intervals prior to, during, and after feedin g, from sows that had developed stereotypies to different degrees over a period of 110 days of restrictive housing and feeding conditions. G lucose concentrations were low prior to and high after feeding. Levels of stereotypies showed similar variations, suggesting that the perfor mance of stereotypies is not related to low glucose concentrations. Fu rthermore, whilst sows differed consistently in glucose concentrations , no correlations were found between individual glucose concentrations and stereotypies. Similarly, no correlations were found between gluco se concentrations and chain manipulation or drinking on a sample to sa mple basis. These data show that although performance of stereotypies is strongly dependent on feeding regime, it is not related to plasma g lucose concentrations.