A partitioning device for animals, in particular for calves, wherein said device is generally parallelepiped in shape, comprising a front side, a rear side, two lateral sides and a bottom, wherein said front side comprises at least two posts each including, on two of their opposite sides, means suitable for the fastening of a lateral edge of a front wall, said front wall including a lower edge, wherein said rear side comprises at least two posts each including, on two of their opposite sides, means suitable for the fastening of a lateral edge of a rear wall, said rear wall including a lower edge, and wherein said posts of said front and rear sides include means in the form of a fitting groove for the fastening of a lateral edge (111, 112) of a lateral wall, to form said lateral sides, said lateral walls including a lower edge, and wherein said fitting grooves are arranged along the whole or almost the whole height of said posts, suitable for the mounting and the holding of said lateral walls by simple sliding, wherein said partitioning device has the possibility to comprise a bottom formed at least in part of a floor/grating system including one floor/grating structure or several juxtaposed floor/grating structures, each of said floor/grating structures including a lower face, an upper face, two end sides and two lateral sides, characterized in that said posts are provided with an embedding through-groove, closed at the top, the lower part of said posts including a base for their fastening to the ground by means of screws, said through-groove being adapted to allow the positioning of said lateral walls by embedding, with a part located on each side of said post, to form a front extension, on either side of said front wall(s), and in that said posts include means for the mounting and the holding of said front wall, and/or said rear wall, and/or said laterals walls, at at least two height indexing levels, in such a way as to allow: - the low positioning thereof, with their lower edge (84, 94, 114) near the ground, or in rest against the latter, in the case where said bottom is formed by the ground, and - the high positioning thereof, with their lower edge (84, 94, 114) remote from the ground, at or close to the level of the upper face of said added floor/grating structure forming said bottom. wherein said front side comprises at least two posts each including, on two of their opposite sides, means suitable for the fastening of a lateral edge of a front wall, said front wall including a lower edge, wherein said rear side comprises at least two posts each including, on two of their opposite sides, means suitable for the fastening of a lateral edge of a rear wall, said rear wall including a lower edge, and wherein said posts of said front and rear sides include means in the form of a fitting groove for the fastening of a lateral edge (111, 112) of a lateral wall, to form said lateral sides, said lateral walls including a lower edge, and wherein said fitting grooves are arranged along the whole or almost the whole height of said posts, suitable for the mounting and the holding of said lateral walls by simple sliding, wherein said partitioning device has the possibility to comprise a bottom formed at least in part of a floor/grating system including one floor/grating structure or several juxtaposed floor/grating structures, each of said floor/grating structures including a lower face, an upper face, two end sides and two lateral sides, characterized in that said posts are provided with an embedding through-groove, closed at the top, the lower part of said posts including a base for their fastening to the ground by means of screws, said through-groove being adapted to allow the positioning of said lateral walls by embedding, with a part located on each side of said post, to form a front extension, on either side of said front wall(s), and in that said posts include means for the mounting and the holding of said front wall, and/or said rear wall, and/or said laterals walls, at at least two height indexing levels, in such a way as to allow: - the low positioning thereof, with their lower edge (84, 94, 114) near the ground, or in rest against the latter, in the case where said bottom is formed by the ground, and - the high positioning thereof, with their lower edge (84, 94, 114) remote from the ground, at or close to the level of the upper face of said added floor/grating structure forming said bottom. - the low positioning thereof, with their lower edge (84, 94, 114) near the ground, or in rest against the latter, in the case where said bottom is formed by the ground, and - the high positioning thereof, with their lower edge (84, 94, 114) remote from the ground, at or close to the level of the upper face of said added floor/grating structure forming said bottom.