[The copper status of cattle in the Netherlands]

During two periods of investigation, at an interval of five years, samples of 333 livers of cows of known origin were collected in the Netherlands. The concentrations of copper were analysed approximately in 0.5 g of dry matter by acid incineration and atomic absorption spectrophotometry. The results showed that there were areas characterised by a rather large number of low concentrations (Leyden, Isle of Texel, southern Limburg) and areas characterised by very high concentrations (Veluwe and Peel areas), the latter probably resulting from the use of pig manure on a large scale. In the present paper the significance of threshold values of the concentrations of copper in the liver are discussed; these were 25 and 400 mg/kg of dry matter, normal copper levels and a normal structure and function of the liver being maintained. On the basis of these threshold values the two investigations revealed too low concentrations of copper in the livers in thirty (17 per cent) of the cases and too high concentrations in eight (17 per cent) of the cases. Sampling livers from slaughterhouses naturally does not produce a representative picture of the entire population of dairy cattle in the Netherlands. None the less the results show that the copper status of cows in the Netherlands not infrequently leaves much to be desired.