Copyright Accademia dei Georgofili
Water is the most simple but more limiting nutrient required for life of living beings. Water is indispensable for all the biological processes, from digestion to excretion. In ruminants, the water also allows the microbe fermentation in forestomachs and the maintenance of rumen functions. These essential role of the water justify the inclusion of thirst among the five freedoms necessary to guarantee a good welfare of animals. In whichever breeding condition, dairy cows need a free access of water, with a high hygiene and chemical quality. The requirement in dairy cows ranges among 35 to 200 L/d, in accordance to physiological status and environmental conditions. In intensive livestock systems, the water accessibility could be limited for many reasons (i.e. grouping strategy, environment, hygienic status). Therefore, the satisfaction of water welfare requires constant attention to quality of offered water and usability of the drinking troughs. Methods of welfare assessment, as the Integrated Diagnostic System (ISDW), can be used to verify the respect of freedom from thirst in intensive and extensive dairy production systems.