Smithfield Foods Inc., the world's largest pork producer and one of the suppliers McDonald's lauded in 2012 as "adopting commercially viable alternatives'' to gestation stalls, says sows still need to be individually confined in the early weeks after insemination to keep them healthy and from being injured in squabbles with other expectant mothers — potentially jeopardizing the pregnancies. Smithfield outlined sows' transition from crate to group housing, once their pregnancies are confirmed by ultrasound, in a 2013 video.