Growing wether sheep were given a low-phosphorus (P) diet (1,06 g P/d) supplemented, with 1,75 g P in the form of either Langebaan rock phosphate (Langfos) or two different calcium phosphates, composed of either a mixture of monocalcium and dicalcium phosphate (MDP) or pure dicalcium phosphate (DCP). Without P supplementation, the sheep were in negative P balance (-0,03 g P/d). When the low-P diet was supplemented with Langfos, 94% of the additional P supplied was excreted in the faeces and only 0,08 g P/d was apparently retained. In contrast, supplementation with MDP and DCP resulted in significantly improved apparent P retentions of +1,10 and 1,01 g P/d respectively. Only MDP and DCP significantly increased blood plasma P concentrations.