Ingestion of iron in sow's faeces by piglets reared in farrowing crates with slotted floors.

1. Two sows were housed in farrowing crates with slotted floors and fed daily with approximately 200 microCi 198Au from 3 d before farrowing until their piglets were 21 d old. 2. Th sows' faeces became radioactive but their milk remained free of radioactivity. The piglets' mean (+/- SE) whole-body radioactivity was equivalent to 8.5 +/- 0.9 g (range 3.8-15.5 g) of faeces. This is probably a measure of their daily intake of faeces. 3. The possibility of using this natural coprophagia to prevent piglet anaemia has been demonstrated on two commercial piggeries by feeding the sows a diet containing 2000 mg Fe/kg.