Described is a valve (5) for a drinking trough wherein the drinking trough (1) comprises a collection tank (2) for containing a food preparation for animals. The valve (5) is configured for supplying the food preparation to the collection tank (2) and for receiving the food preparation from supply piping (4) of the food preparation. The valve (5) comprises a valve body (100) having an inlet chamber (101) and an outlet chamber (102), coaxially positioned along a common axis (X), a conduit (110) with a narrowed section between the inlet chamber (101) and the outlet chamber (102); a shutter (104) mounted on the valve body (100), in a slidable fashion along an axis (X), and having a stem (105) at least partly inserted inside the conduit (110). The shutter (104) also comprises a closing plate (107), coupled to a first end (105a) of the stem (105) and configured for abutting a first shoulder (103a) in a closed condition of the valve (5), in such a way that when the pressure of the food preparation inside the inlet chamber (101) is below a predetermined value, the closing plate (107) is kept spaced from the first shoulder (103a) by means of an opposing member (109) and the food preparation can flow from the inlet chamber (101) to the outlet chamber (102), whilst when the pressure of a cleaning liquid inside the inlet chamber (101) is above the predetermined value the closing plate (107) causes a closing the valve (5). The closing plate (107) comprises a cup-shaped body (120) provided with a bottom (121), from which extends the stem (105), and an annular sealing element (107a) made of elastomeric material, the sealing element (107a) surrounding the stem (105) and being housed in the cup-shaped body (120) for making a fluid-tight seal with a planar annular portion of the first shoulder (103a) in the closed condition of the valve (5).