Inorganic ions in the intestinal and caecal contents of germ-free and conventional chickens.

In 4-week-old chicks that had been maintained on 3 different diets, caecal weights were lower in germ-free than in conventional birds eating practical but not semipurified diets. There were no consistent differences in total sodium, potassium and chloride ions in the contents of the small intestine. In germ-free chicks the caecal wall muscle appeared lacking in tone and there was a lower concentration of chloride ions in the contents, but there was no caecal enlargement comparable to that in germ-free rodents.