A trough is disclosed that may be extended to accommodate a large number of animals feeding at the same time. The trough has an elongate trough body (12) and at least one elongate support element (14, 15). The trough body comprises at least one longitudinal side wall portion (18,19) and a bottom portion (16) which are integral with one another, or attached to one another along respective longitudinal edges. The support element extends along the outer face of the side wall portion, lower than an upper edge of the side wall portion but higher than the bottom portion. The support element may be restrained from moving outward, away from a longitudinal trough centreline, by connecting a restraint (26) located inside the trough to the support element. The side wall portion is maintained upright partly by tension in the support element or in the restraint. In one embodiment, a plastics sheet material is bent into a U-shape with opposite side walls (18,19) supported upright by tension in longitudinal supporting wires (14,15) and transverse restraint wires (26), the ends of which connect to the support wires through respective perforations (30) in the side walls.
