Abstract: In rows of mink cages in mink farms it is characteristic that the animals relieve nature in the same end of the cages in which the animals' drinking valves are mounted, and the surplus water from the drinking valves, therefore, gets mixed with the manure, whereby the required manure tanks have to be much larger than necessary for the mere collection of the manure. According to the invention the drinking valves (4) are designed so as to produce a minimum of surplus water, but it is an associated risk that the valves may then fail to function in case of even quite small foreign bodies occurring in the watering water.