Game domestication for animal production in Kenya: feeding trials with oryx, zebu cattle and sheep under controlled conditions

Abstract

SummaryDigestibility trials were carried out with five individuals each of domesticated oryx, sheep and cattle, using three diets ranging from 12·5 to 7·4% crude protein. Feed intake, water consumption and urine production were measured.Intakes of dry matter (as g/day or g/kg W0·75/day) did not differ between diets for any species. On a metabolic weight basis the sheep and oryx ate the same amount. The cattle ate more than the sheep of all three diets, and more than the oryx in two of the three.For all three species, digestibility of dry matter, crude protein and crude fibre was lower when the lower quality food was given. On any single diet, significant differences in digestive efficiency for any diet component between species were few and small.Total daily intakes of water (ml/kg W0·85/day) were lower for each species when eating the diet with the lowest protein content. On each diet total intakes were significantly different in the decreasing order cattle > sheep > oryx, in the mean ratio 3·3:l·7:10.Urine production (ml/kg W0·85/day) varied slightly between diets for each species. On each diet the cattle produced significantly more urine than the sheep or oryx. The ratio of urine produced to water drunk decreased in the order oryx > cow > sheep, in the mean ratios 0·63, 0·34 and 0·27. Despite some interspecific differences in nitrogen concentration, there were few differences in the proportion of total excreted nitrogen that was lost through the urine.Calculations of evaporative water loss showed that loss of water by this avenue was significantly less in oryx than in sheep or cattle, which did not differ significantly.In the absence of any evidence of a more efficient digestion, the low metabolic intake of food by oryx suggests a low metabolic rate. The oryx's low water consumption and small evaporative loss are obvious adaptations to its desert habitat.