Serum cortisol concentrations in gilts and sows housed in tether stalls, gestation stalls and individual pens

Three experiments were conducted to determine whether housing in tether stalls, gestation stalls or individual pens imposes a stress upon gilts and sows. Changes in serum cortisol concentrations were used as the indicator for stress. In the first experiment, gilts were placed in tether stalls and individual pens to determine cortisol concentrations after tethering and to see if this response was different from gilts that were previously tethered for two weeks. In the second experiment, gilts were tethered in order to determine if penning in tether stalls altered the circadian rhythm of cortisol. In the third experiment, breeding sows were placed in tether stalls, gestation stalls or individual pens to determine if a ten-hour profile of cortisol concentrations were altered and if such housing affected a sow's response to transfer to farrowing crates. The results indicate that the initial response to tethering varied among gilts and sows and this variation appeared to be due to previous penning and human handling experiences. When tethering was stressful, acclimation required up to four days. However, once acclimated, tethering resulted in higher morning concentrations which may be associated with the greater activity that occurs at this time. Housing in tether stalls, gestation stalls or individual pens was not a stress for breeding sows and did not alter sows' responses to transfer into the farrowing crate.