Scientists with the ARS Livestock Behavior Research Unit in West Lafayette, IN, recently looked at the temperature preferences of sows, with an eye toward keeping them more comfortable before and during pregnancy. Current temperature guidelines are more than 30 years old and may not be what today’s larger and faster-growing pigs need. They also don’t specifically address pregnant sows. Heat stress in pigs reduces welfare, feed intake, and growth rates, so keeping them comfortable is important.

Along with collaborators at Purdue University and the University of Illinois, the scientists studied nonpregnant sows and those in mid- to late pregnancy. They designed a system that allowed the sows to choose which temperature they wanted to be in. The temperatures in the test apparatus ranged from 50.7° F to 86.9° F, which was a greater range than what is currently suggested to keep pigs comfortable (50° F to 77.0° F). Results showed that the sows preferred temperatures between 54.7° F and 61.5° F, and the sows in late pregnancy preferred the cooler end of that range. This knowledge could benefit sow welfare and may provide an economic benefit to producers by reducing energy costs related to heating animal facilities during cooler times of the year.