Variation in circulating Cortisol is often used as an indicator of stress in farm animals. In this study the variation in baseline salivary Cortisol of farrowing and lactating sows was examined, to assess their physiological response to three different farrowing systems. It was part of a larger project examining alternative farrowing systems.

Three farrowing systems in neighbouring rooms were compared. In two systems the sows were loose-housed and could move freely: five strawed pens (2.5m x 1.5m) with farrowing rail (Pen), and five crates modified to allow the sows to walk through (Free Crate). Sows had access via a passageway to a transponder-controlled feeder and a north facing outside area with two water drinkers.