Plasma electrolyte concentration in food-deprived goats orally supplemented with potassium chloride

The aim of the present study was to investigate whether oral potassium supplementation during food deprivation could stimulate rumen electrolyte absorption and maintain plasma electrolyte concentration. Eight goats were subjected to food deprivation in combination with intrarumen loads of potassium chloride or, as a control, mannitol in a change-over design. In addition, four KCl- and four mannitol-treated goats were given an extra KCl load towards the end of the experiment. Food-deprived goats which were given KCl maintained their plasma concentration of Na and Cl, while plasma K concentration increased from 3.6 mM to 4.4 mM. In control goats receiving mannitol during food deprivation, the plasma concentration (mM) decreased from 144 to 140 for Na, 105 to 100 for Cl and from 3.8 to 3.6 for K, but concentrations were restored when these goats were given a load of KCl. The plasma renin activity was suppressed in food-deprived goats receiving KCl, while those given mannitol showed increased activity. It is suggested that the hyponatraemia which occurs in food-deprived ruminants is mainly caused by diminished K intake.