An investigation was conducted to ascertain whether a source of feed lime (Ouplaas lime) high in manganese (5000 mg Mn/kg) is a safe feed ingredient for sheep. Two levels of Ouplaas lime, l% and 4%, were included in a sheep finishing diet and compared with another lime source (Kulu lime; 45 mg Mn/kg) which was included at the same levels in the diets. Lambs were fed individually for 69 days. In the final feed mixtures none of the diets contained toxic levels of any minerals. No significant differences between treatments with the same level of lime inclusion occurred in: growth rate, feed intake and utilization, plasma enzyme levels, mineral concentrations in plasma, faeces and kidneys, mineral content of livers, haematology, histopathology of livers and kidneys and bone measurements. It is concluded that the Ouplaas lime, when included at realistic concentrations in diets, poses no risk to the health of sheep.