Quantifying chronic stress in group- and stall-housed sows during gestation using cortisol in hair

The objective of this study was to characterise chronic stress in gestating sows (n = 66; parity 0-6) housed within the same facility, assigned to gestation stalls or group pens (25 sows per pen) within two days of breeding until day 111 (± 1.4) of gestation using hair cortisol concentrations (HCC) as a biological marker of longer-term stress. Hair was shaved from the right hip at day 6.0 (± 3.8), day 37, day 74, and day 111 of gestation; day 37 and day 111 samples were analysed for cortisol. Housing system, parity class (0-1 [n = 23], 2-3 [n = 17], and 4-6 [n = 26]), and their interactions were explored. Stall-housed parity 0-1 females had higher HCC than all other females regardless of housing system, suggesting that gilts and parity 1 females in stall housing may experience greater chronic stress during gestation.