An official journal of the Society for Biology of Reproduction and the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn

September 2014 (No. 3)

Hair cortisol determination in sows in two consecutive reproductive cycles

Maria Laura Bacci*, Eleonora Nannoni, Nadia Govoni, Fabrizio Scorrano, Augusta Zannoni, Monica Forni, Giovanna Martelli, Luca Sardi

Department of Veterinary Medical Sciences, DIMEVET, University of Bologna, Via Tolara di Sopra 50, Ozzano dell’Emilia, 40064 Bologna, Italy

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Hair analysis has been proposed as a minimally invasive technique capable of furnishing information regarding the stress response during medium- and long-term periods. Bristle samples were collected from the rump region of sows at three key physiological phases (before delivery – BD; weaning time – WT; pregnancy diagnosis – PD) during consecutive reproductive cycles in order to test swine hair as a reliable matrix of cortisol evaluation. Cortisol was extracted from the bristles and assayed using radioimmunoassay. The highest mean hair cortisol concentrations were demonstrated (p < 0.001) at the PD time points (20.1  ± .95 and 16.29  ± 2.15 pg/mg). Moreover, cortisol was significantly higher (p < 0.001) at BD2 (10.48  ± 0.96 pg/mg) as compared to BD1 (5.17  ± 0.51 pg/mg) and WT1 (6.01  ± 0.47 pg/mg). The various physiological phases had a significant effect on cortisol concentration (p < 0.00001) with a higher cortisol concentration found during late pregnancy and lactation than in early- mid pregnancy. This could be due not only to the physiological hormonal status, but also to the different housing conditions (single crates vs. group housing). The season of the year was also observed to have an effect (p < 0.005), with the lowest cortisol concentration recorded during the hot season.

Reproductive Biology 2014 14  3: 218-223.

* Corresponding author: E-mail addresses:, (M.L. Bacci)