US pork producers approved a resolution that farmers should be able to select a sow housing system, including gestation stalls or individual maternity pens, to best promote employee safety and animal care, at the 2013 National Pork Industry Forum.

A survey conducted in 2012 by University of Missouri Extension economist Ron Plain, found that currently 17.3 percent of sows spend a portion of gestation in open pens. Plain surveyed pig farms with 1,000 or more sows and received responses from 70 farms, which combined own about 3.6 million of the 5.7 million sows in the United States.

Plain's survey also found that 20.2 percent of sows on operations with 1,000 to 9,999 sows, 18.9 percent on farms with 10,000 to 99,000 sows and 16.4 percent on farms with more than 100,000 sows are in open pens for some portion of gestation. 

When asked about plans to put more sows in open pens, the largest pig farms indicated that 23.8 percent of their sows would be in them in two years; farms with 10,000 to 99,999 sows would have 21.3 percent of their pigs in such pens; and farms with 1,000 to 9,999 sows would have 20.7 percent. 

A recent National Pork Board producer survey found that farms producing fewer than 5,000 hogs per year (approximately 200 sows or less) were more likely to use some form of open housing.