It is permitted to place [the slats] close to the well, provided that a cow has its head and most of its body within while drinking. It is permitted to place [the slats] at any distance, provided one increases the slats.

R’ Yehudah says: Until two beis-seah. They said to him: ‘They did not state two beisseah except in regard to a garden or karpeif. But if it was a fold, a corral, a backyard or a courtyard, even five korin, even ten korin, it is permissible. And it is permitted to place [the slats] at any distance, provided one adds slats.’’