Little is known about the impact of social and environmental enrichment on improving livestock resilience, i.e. the ability to quickly recover from perturbations. We evaluated the effect of an alternative housing system (AHS) on resilience of pigs, as compared to conventional housing (CONV). The AHS consisted of multi-litter housing during lactation, delayed weaning, extra space allowance and environmental enrichment at all times. We assessed recovery to a 2 h-transport challenge, an LPS injection, 2 h-heat stress and a biopsy wound in 96 pigs. Additionally, indicators of long-term “wear and tear” on the body were determined. AHS pigs had better physiological recoveries with quicker returns to baseline in the transport and LPS challenges, showed lower cortisol accumulation in hairs and lower variance in weight gain over the experimental period compared to conventionally-housed (CONV) pigs. They also had higher levels of natural antibodies binding KLH than CONV pigs. Their response to heat stress revealed a different strategy compared to CONV pigs. Taken together, AHS pigs appear to be more resilient and experience less chronic stress. Enhancing welfare by provision of social and environmental enrichment that better meets the behavioural needs of pigs seems to be a promising approach to improve their resilience.

The gut microbiota is involved in host behaviour and memory in mammals. Consequently, it may also influence emotional behaviour and memory in birds. Quail from two genetic lines with different fearfulness (LTI: long tonic immobility, n=37; STI: short tonic immobility, n=32) were either or not supplemented with a probiotic (Pediococcus acidilactici) from hatching. Emotional reactivity was measured in a tonic immobility test (d6 and 7 of age) and two open-field tests (d13-15; d22-24). Memory was measured in a test rewarded with mealworms, where quail had to remember the cups previously visited (d34-36). Quail endured a 5-days stress period from days 17 to 21 to help revealing the potentially beneficial effect of the probiotic. As expected, STI quail were less fearful compared to the LTI quail (p<0.05). Probiotic supplementation had no effect on most measures of emotional reactivity (p>0.05), except in the tonic immobility test where supplemented STI quail had lower immobility duration (p=0.0001). Regarding the memory test, the two lines had similar performances. Quail fed with probiotics made fewer errors (p=0.040). There was no significant correlation between traits of emotional reactivity and of memory. In conclusion, the supplementation with Pediococcus acidilactici as a probiotic, affected a specific trait of emotional reactivity in STI quail, and improved memory in both lines, whichstrengthens the idea that the influence of gut microbiota on the host behaviour and memory seen in mammals is shared by birds.