Analysis of Hair Cortisol as an Indicator of Chronic Stress in Pigs in Two Different Farrowing Systems

In 2021, a study was conducted on 60 sows to determine if hair cortisol concentration (HCC) could be used as an indicator of chronic stress in pigs. The sows were divided into two groups, housed in either conventional or loose farrowing systems. The study found that HCC varied from 0.49 pg/mg to 8.92 pg/mg with an average of 1.99 ± 1.23 pg/mg for all samples. However, there was no significant difference in HCC between the two farrowing systems, nor was it affected by factors such as the sows' parity, number of piglets born alive, number of weaned piglets, total piglet loss, skin lesion score, udder lesion score, individual body weight loss during the study period, the occurrence of stereotypies or climatic conditions in the compartment. The study concluded that the use of HCC in sows for comparing the effect of different farrowing systems on animal welfare remains questionable, and further research is needed to validate the measured values.