Observations were made, from 1970 to 1975, of the liver copper (Cu) levels of lambs reared on various feeding regimes and of lambs which were stillborn or died within the first 7 days of birth in what was considered to be a normal healthy flock.

Artificially reared Finnish Landrace × lambs were fed on reconstituted milk substitute and a concentrate containing 4 and 8 mg Cu/kg DM, respectively. Liver Cu levels were determined when lambs were slaughtered at 4/5 months of age. In one group, liver Cu levels varied from 500 to 1600 mg/kg DM without any evidence of Cu toxicity in any lambs, whilst, in another group, levels ranged from 50 to 600 mg/kg DM.