A comparison of gastrointestinal water content and osmolality in East African herbivores during hydration and dehydration

Abstract

A wealth of information is available concerning the ‘normal’ gastrointestinal mechanisms within various species of herbivores (Alexander, 1962; Church, 1971; Quarterman, Phillips & Lampkin, 1957). In addition, the effect that dehydration has upon the physiology of digestion has also been investigated (Schmidt-Nielsen et al. 1956; Schmidt-Nielsen, 1964; Maloiy, 1972; Macfarlane et al. 1972). This communication presents preliminary observations on the effect that dehydration hasupon gastrointestinal water content, as a percentage of total gut contents, and fluid osmolality (m-osmol/kg H2O). A comparison was made under controlled laboratory conditions between six species of domestic herbivores fed identical diets and exposed to a simulated desert environment