Water is the most important feedstuff. For this reason it is crucial that it is available to the animals in sufficient amounts and that it is micro-biologically immaculate. A common source of entry for germs in the water pipes is, for example, the drinking nipple. Through saliva, food remains and faeces, E. coli and Co. can quickly make their way into the drinking water system. This entry is often not tended to and remains unconsidered under the hygiene concept for water.