Feeding trough for poultry farming wherein the feed is automatically supplied from a vertically displaceable horizontal dispensing tube, comprising: - a bell-like housing provided superiorly with an attachment member for connecting to the horizontal feeding tube, - a plate arranged beneath the bell-like housing to receive the feed, - means for adjusting the amount of feed transferred from the bell-like housing to the plate actuated following raising or lowering of the horizontal dispensing tube and consequent relative vertical displacement between the bell-like housing and the plate between a lowered and a raised position, wherein: - the attachment member comprises a tubular connector formed in one piece with the bell-like housing and a clamping element secured to said tubular connector, - the bell-like housing is provided inferiorly with a crown of apertures, - the plate is formed in one piece with a dome extending within the bell-like housing and defining therewith an annular chamber for the passage of the feed from said tubular connector to the plate, and - the plate is formed in one piece with a ring which in the lowered position of the bell-like housing opens said crown of apertures and in the raised position of the bell-like housing closes said crown of apertures so as to reduce the amount of feed transferred to the plate, said feeding trough being characterized in that: - said plate is rotatable relative to the bell-like housing and said dome is provided with substantially helical projections for rinsing the feeding trough by means of a liquid under pressure introduced into said annular chamber through an inlet hole of the bell-like housing, whereby a pressure of said pressurized liquid introduced into the annular chamber and exerted on said projections rotatably drives said plate. - a bell-like housing provided superiorly with an attachment member for connecting to the horizontal feeding tube, - a plate arranged beneath the bell-like housing to receive the feed, - means for adjusting the amount of feed transferred from the bell-like housing to the plate actuated following raising or lowering of the horizontal dispensing tube and consequent relative vertical displacement between the bell-like housing and the plate between a lowered and a raised position, - the attachment member comprises a tubular connector formed in one piece with the bell-like housing and a clamping element secured to said tubular connector, - the bell-like housing is provided inferiorly with a crown of apertures, - the plate is formed in one piece with a dome extending within the bell-like housing and defining therewith an annular chamber for the passage of the feed from said tubular connector to the plate, and - the plate is formed in one piece with a ring which in the lowered position of the bell-like housing opens said crown of apertures and in the raised position of the bell-like housing closes said crown of apertures so as to reduce the amount of feed transferred to the plate, - said plate is rotatable relative to the bell-like housing and said dome is provided with substantially helical projections for rinsing the feeding trough by means of a liquid under pressure introduced into said annular chamber through an inlet hole of the bell-like housing, whereby a pressure of said pressurized liquid introduced into the annular chamber and exerted on said projections rotatably drives said plate.