Influence of controlled ambient temperatures and diets on the incidence of esophagogastric ulcers in swine.

A N indication that seasonal variation may influence the incidence of esophagogastric ulcers in swine has been reported by Kowalczyk et al. (1960), Kowalczyk and Muggenburg (1963) and Curtin et al. (1963). More ulcers and deaths due to ulcer were observed during the spring and winter months. The possibility that the temperature changes which occurred during this time were placing an increased stress on the animal is one explanation. The ulcerogenic effect of stress on man and laboratory animals has been characterized (Gray et al., 1956; Bonta, 1965). The stress response causes an increased adrenal activity which influences gastric secretion of hydrochloric acid and pepsin production. Also gastro-intestinal ulceration is an integral part of the alarm reaction in stress. The protective action of ascorbic acid in ulcer production and relationship to stress in rat and man has been reported by Freeman and Hafkesbring (1954) and Doss (1965). The objective of the research reported in this paper was to test the effects of temperature as a stressor on the incidence of esophagogastric ulcers in pigs fed raw or expanded corn. The level of plasma ascorbic acid was also determined to see if the ulcer formation might be associated with lowered ascorbic acid levels.