Abstract
<title>Abstract</title> <p> Post-weaning diarrhoea is a multifactorial disease associated with the weaning transition, but little is known about the effects of environmental and social enrichments on its occurrence. We investigated the effects of physical and social enrichments on health indicators of piglets challenged with enterotoxigenic <italic>E. coli</italic> (ETEC), as a model of post-weaning diarrhoea. We divided a total of 119 specific pathogen-free piglets between two contrasting housing conditions: minimal (MIN) versus enriched with increased space allowance, rooting material, a rotation of objects and early socialisation (ENR). Eleven days after weaning, piglets were orally inoculated with either ETEC bearing F4 adhesins (inoculated pens) or sterile broth (control pens). We monitored piglets’ health for four weeks, with regular clinical observations, faecal and blood samplings. Regardless of inoculation, ENR pigs had overall more D-lactate and leucocytes compared to MIN pigs, suggesting different microbiota and immune systems functioning. ETEC shedding peaked at higher levels in ENR-inoculated pigs than in MIN-inoculated pigs, without detrimental effects on clinical signs, growth performance or metabolism. Therefore, environmental and social enrichments appeared to increase the susceptibility of ENR challenged pigs to the bacteria but not their disease resilience, i.e., coping with the consequences of the pathogen burden. </p>