Nitrogen metabolism and renal function in the dik-dik antelope (Rhynchotragus kirkii)

Nitrogen metabolism and kidney function of the dik-dik antelope (Rhynchotragus kirkii) were studied under a range of controlled, experimental conditions and diets. Dik-dik antelope remained in nitrogen balance even when fed a diet low in protein and high in fibre. When fed a diet high in protein (20%) and water ad-libitum, 55.3% of the urea filtered by the kidney was reabsorbed. Limiting water intake increased urea reabsorption to 77.2%. The U/P urea concentrations were maintained at similar ratios on all diets, as well as during dehydration and solute loading. Minimum endogenous nitrogen excreted was 74mg/kg(0.75)/day. Dehydration (water deprivation) and solute loading (intraruminal infusion of 0.25M NaCl) had varying effects on nitrogen metabolism. It is concluded that the metabolic nitrogen economy of the dik-dik antelope is qualitatively similar to that of other domestic and wild ruminants.