Changes in Gastrointestinal pH Associated with Fasting in the Laying Hen

Abstract

THE hydrogen ion cencentration varies from one portion of the intestine to the next, depending to some extent on certain variables; the more obvious being the type of material collected for analysis i.e. collected ingesta as opposed to intestinal tract scrapings. Variability will depend also on time elapsed after feeding and type of electrode used. Generally, the pH scale from the crop to the cloaca (Sturkie, 1954) is considered to be on the acid side. The literature contains several reports of the influence of diet on the gastrointestinal pH. Neff (1931) reported that lactic acid, mineral oil and water lowered the pH of the excretory products. The terminal portion of the duodenum is reported acidic due to the presence of amino and fatty acids (Shaw, 1913). However, there is considerable literature (Mussehl, Blish and Ackerson, 1933; Heller and Penquite, 1936; and others) which would indicate that the type of diet …