Influence of the buffering capacity of the feed on the precaecal digestibility in pigs

Diets with a high buffering capacity (BC) stimulate the gastric acid secretion. After leaving the stomach the acid is back-titrated with bicarbonate. Therefore a high BC most likely will result in a stimulated pancreatic secretion with possible repercussions on the small intestinal digestion. Present experiment, using 2 precaecal cannulated pigs, was set up to compare the effect of two diets only differing in the mineral supplements used: H = high BC and N = normal BC. The H diet caused an acute and dramatic malabsorption (10-15%-units, p<0.01) of all the nutrients studied and an increase of the ileal flow rate from 5.0 to 6.8 kg/d (p<O.OO1). This and the fact that all nutrients were involved indicate that the malabsorption most likely was due to a dilution of the digestive enzymes and/or a shorter retention time.