THE EFFECT OF PIGLET STIMULI ON THE POSTURE CHANGING BEHAVIOR OF RECENTLY FARROWED SOWS

Twenty-four primiparous sows that had recently farrowed in commercial farrowing crates were tested in a 2 x 2 factorial experiment for their behavioural response to piglet stimuli during the process of changing from a standing to a lying posture. The piglet stimuli presented were those that a sow may perceive prior to an overlay situation, where the sow crushes a piglet beneath her body. The experimental treatments were (1) tactile stimulus (model piglet under the sow's udder); (2) auditory stimulus (piglet distress vocalizations). The application of either stimulus produced significant (P < 0.05) effects on the behavioural response of kneeling sows. The greatest effect was on the incidence of sows that did not proceed to lie down after kneeling. All 6 sows stood up when both stimuli were presented together, compared with 7 of 12 sows when either stimulus was presented individually and 0 of 6 sows when neither stimulus was presented (chi-2(2) = 12.25, P < 0.01). The results suggest that recently farrowed sows are able to alter their posture-changing behaviour in response to piglet stimuli and thus avoid overlying piglets.