The effect of supplementation or fertilizer application on the utilization by sheep of Stylosanthes guianensis grown on sulphur deficient soils

Abstract

Merino wethers held in individual metabolism crates were fed one of the following: a control diet of Stylosanthes guianensis; S. guianensis supplemented with 0.5 g sulphate-sulphur per head per day; or S. guianensis which had been fertilized with superphosphate (1 2 per cent S). The daily dry matter (DM) intakes and DM digestibilities of the three diets were 142 g, 0.203; 202 g, 0.296; 268 g, 0.352 respectively. The digestible dry matter intake of the animals supplemented with sulphate-sulphur was, therefore, double that of the controls, and that of animals fed fertilized hay, treble. The magnitude of the responses in each case were modified by the availability of other dietary constituents, notably nitrogen. In a second period DM intake of sheep supplemented with sulphate-sulphur and those fed fertilized S. guianensis was further increased by supplements of sodium chloride.