Preliminary Evidence Regarding the Detection of Cortisol and IL-6 to Assess Animal Welfare in Various Rabbit Housing Systems

The main purpose of this study was to investigate the influence of three different rabbit rearing systems using animal-based measures. Therefore, in 2021, cortisol and IL-6 were assessed during a Biosecurity System pilot program to evaluate rabbit welfare, based on EU Regulation 2016/429 in the Apulia region of Southern Italy. The study was carried out on a total of 45 meat-type rabbits, divided into 3 groups of 15 subjects, aged approximately 60-65 days. Groups came from either: (i) a niche open-air system; (ii) a niche system in a shed with conventional cages, or (iii) an industrial system. Based on our findings, the rearing system had a significant effect (p < 0.0001) on the animal-based measures. Cortisol levels were higher in rabbits raised in the niche open-air system compared to those raised in both the niche system located in a shed with conventional cages and the industrial system (11.91 vs. 2.86 and 2.72 ng/mL, respectively). Likewise, IL-6 values were higher in rabbits from the niche open-air system (45.80 ng/mL) and lower in rabbits from the niche system in a shed with conventional cages and those from the industrial system (23.30 and 16.80 ng/mL, respectively). According to the results of the stress indicators measured, cortisol and IL-6, rabbit welfare and meat quality may be affected by rabbit rearing systems.