This water supply system for watering chickens raised in cages (60) is configured to comprise: a water supply pipe (3) disposed along a cage row (70)； a plurality of water suppliers (4) provided to the water supply pipe； a pressure reduction device (2) for reducing the pressure of water which is sent from a water supply source, and causing the water to flow into the water supply pipe； an opening and closing valve (5) switched to either a closed mode in which the downstream end of the water supply pipe is closed, or a discharge mode in which the downstream end of the water supply pipe communicates with a discharge pipe (6)； a cooling panel (30) provided with a water-permeable panel material (35) for covering the air inlet opening (21) of a chicken house (10), and also with a supply pipe (36) for supplying water to the upper surface of the panel material, the cooling panel (30) cooling, by means of the panel material of which the temperature has been reduced by the heat of vaporization of the water, air flowing through the air inlet opening； a water storage tank (40) provided below the cooling panel (30) and receiving water having flowed down from the panel material； and a pump (P) for delivering water in the water storage tank to the supply pipe. Water flowing through the water discharge pipe is conducted to the water storage tank.L'invention concerne un système d'alimentation en eau servant à abreuver des poulets élevés dans des cages (60), système qui est configuré pour comprendre : un tuyau d'alimentation en eau (3) disposé le long d'une rangée de cages (70) ； une pluralité de dispositifs de fourniture en eau (4) disposés sur le tuyau d'alimentation en eau ； un dispositif de réduction de pression (2) servant à réduire la pression de l'eau qui est envoyée à partir d'une source d'alimentation en eau, et servant à amener l'eau à s'écouler dans le tuyau d'alimentation en eau ； une soupape d'ouverture et de fermeture (5) commutée soit en mode fermé dans lequel l'extrém
