Influence of Feed on Residues and Contaminants in Milk

For different reasons special attention is paid to milk in public discussion on residues and contaminants. Its role in the food chain and — as a consequence — in the burden on man is strongly influenced by concentration and deconcentration effects which are mostly related to contamination pathways via feed.Chemical compound groups of residues and contaminants of major importance are presented in a brief overview, with particular reference to their present significance for the contamination of milk as well as pathways and sources of contamination as far as they are related to feed.Scientific results and practical experience, as well as the key role of research on sources of contamination, practical care of the farmer and environmental protection measures to control milk contamination are emphasized.Analysis of feed and milk for residues and contaminants means a particular challenge with respect to problem dependent analytical strategies to secure contamination of milk at the lowest possible level,strategies of sampling in research on sources of contaminationand assurance of accuracy of results, where different matrices, matrix interferences, (sometimes considerably) different ranges of concentration, blank values etc. need to be considered.A few examples will show that substantial analytical progress has been achieved in the past but that — on the other side — many unreliable and even completely wrong results are still taken as a basis for evaluation.By different measures at different levels, contamination of milk has been considerably, sometimes even drastically lowered for most contaminants during the last 20 years.