Sows’ Responses to Piglets in Distress: An Experimental Investigation in a Natural Setting

Domestic pigs (Sus scrofa) possess complex socio-cognitive skills, and sows show high inter-individual variability in maternal behaviour. To evaluate how females—reared under natural conditions—react to the isolation calls of their own piglets or those other females, we conducted observations experimental trials. In January–February 2021, all-occurrences sampling on affiliation, aggression, lactation (daily, 7:30–16:30 h) six lactating four non-lactating females at ethical farm Parva Domus (Turin, Italy). The trials (30 s each, n = 37/sow) consisted briefly catching restraining a piglet. We recorded sow response (none/reactive/proactive movement towards piglet; self-directed anxiety behaviours such as body shaking) before during trial control conditions. Increased levels behaviour were accompanied by an increased frequency responses. Less aggressive showed highest frequencies response. Finally, calls’ maximum intensity had influence type observed, with higher proactive following lower calls. Our results suggest that being could play key role increasing specific acoustic features may