Electrolyte levels and net fluid and electrolyte movements in the gastrointestinal tract of weanling swine

Electrolyte concentrations, osmolality and pH were determined in conventionally raised weanling swine fed a liquid diet. Incorporation of a dilution marker into the diet in combination with frequent feeding enabled estimations as to the sites of relative fluid and electrolyte absorption and secretion along the gastrointestinal tract. Unlike many other species the weanling pig depends largely on its large intestine for absorption of fluid and electrolytes with small changes in net fluid movement occurring along the jejunal and ileal segments. Additional observations included the absorption of water by the porcine stomach which increased dilution marker concentration by approximately twofold and the high osmolality values recorded in the small and large intestine. The implications of these observations are discussed with regard to pathogenesis of colibacillary diarrhea in the weanling pig.