Dietary Sodium Bicarbonate and Stereotypic Behavior of Gestating Sows

Purdue University 2003 Swine Research Report. Sows in confinement housing systems often perform repetitive behaviors such as bar-biting, sham-chewing and drinker pressing. These behaviors are considered stereotypic; that is, they are repetitive, relatively invariant behaviors with no obvious function. They are often termed abnormal and have been implicated as indicators of poor welfare in many species, including swine. There is evidence that feed restriction plays a significant role in the development of these behaviors, and their prevalence is highest immediately after feeding. In another natural-forager, monogastric animal, the horse, a number of studies suggest that oral stereotypies are associated with feeding concentrates and are also associated with gastric ulceration. Their performance stimulates saliva production and when fed antacids, ulceration of the horses stomach decreases. Sows are also natural foragers, are restricted-fed a concentrate diet, and are similarly known to have problems with gastric ulceration. Therefore, our working hypothesis was that these oral stereotypies actually functioned to increase saliva flow and buffer stomach acidity. Furthermore, by adding dietary buffer in the form of sodium bicarbonate, we would reduce the amount of oral stereotypic behavior that the sows performed.