Risky behaviour by piglets: a trade off between feeding and risk of mortality by maternal crushing?
Accidental crushing by the sow is a major cause of death among domestic piglets. Piglets risk being crushed if they are underneath the sow as she lies down, but they may benefit from staying close to the sow by improving their access to teats during nursings and by increasing milk production. The prediction was tested that piglets with relatively low weight gains, and thus in greatest need of energy or nutrients, would spend more time in close proximity to the sow and therefore assume a higher mortality risk from crushing. Piglets (N=138 from 17 litters) were highly variable in birth weight, weight gain, and the amount of time they spent in the risky area underneath a standing or sitting sow. As predicted, piglets that had gained less weight spent more time in this risky area. The relationship held both within and between litters, and was largely because poor-gaining piglets spent more time actively nuzzling the sow’s udder, an activity that may increase milk production of a teat.
WEARY, D. M., PAJOR, E. A., THOMPSON, B. K., & FRASER, D. (1996). Risky behaviour by piglets: a trade off between feeding and risk of mortality by maternal crushing?. Animal Behaviour, 51(3), 619-624. https://doi.org/10.1006/anbe.1996.0066