[Rules to control ddrinking water supply systems in livestock farming].

Water is regarded as one of the most important distributors of infectious diseases. Moreover it can carry chemical compounds and toxic substances. Presently there are no specific legal regulations which define the quality of the drinking water for animals in Germany. However, some rules and criteria exist which help to survey and secure the water supply of animals on farm level. When controlling the hygienic quality of water on the farm it is necessary to investigate not only the water itself but also the local facilities around the water well. If health problems occur in the stock the water tanks, the tubing system which distributes the water in the animal houses and the drinkers have to be checked carefully. Water samples for the analysis on microorganisms and chemical contaminants should be taken according to a strict protocol. The regulations of the German drinking water directive for humans can be used as an orientation to characterise the drinking water quality for the animals. Nevertheless it seems useful to elaborate animal species specific thresholds for water contaminants particularly for food producing animals. A proposal for some threshold values is reported.