In a farrowing pen which includes a pit and over the pit a first floor portion on which the sow can stand and lie and two further floor portions on each side of the first floor portion for receiving piglets of the sow and confining walls for locating the sow on the first floor portion there is provided an apparatus for lifting the sow away from the piglets to prevent crushing. The apparatus includes a base carries above the pit on a cradle and a gas bag lift mechanism carried on the base above the manure and arranged to raise a plate carrying two parallel rails with the first floor portion thereon. An air valve extends through the flooring and is operated by pressure from contact with the sow for actuating the controlling the flow of the air. The rate of lifting is faster than the rate of lowering. A scissors lever arrangement mounted on the base above the pit acts to support and guide the floor on the bag.