Evaluating measures of exploratory behaviour in sows around farrowing and during lactation—A pilot study

There are very few studies on the need to perform exploratory behaviour of sows around farrowing and during lactation, except for during the nest-building period. Exploratory behaviour in pigs may reflect appetitive foraging motivated by hunger, or appetitive behaviour related to other motivations, such as nest building. However, exploration may also be motivated by curiosity, stimulated by novelty or search for novelty. The aim of this study was to test novel methods of evaluating exploratory motivation in sows around farrowing and during lactation. We used ten second or third parity sows, housed in conventional crates from day 8 before expected farrowing until weaning, on day 28 after farrowing. Motivation to perform exploratory behaviour was evaluated by measuring the use of a manipulable and chewable object (a wooden device, MCO) and responses during a novel object test (NO). In addition, we studied if exploratory motivation is related to the energy status of the sow, measured as sow weight change during lactation, piglet weight gain, and leptin level in saliva. The exploratory motivation of sows appeared to change during the period of study. Although all sows used the MCO, the use was very low throughout the study (below 3 g per day on average), and almost non-existent during the first weeks after farrowing. The latency to touch the object in the NO test was correlated between test days before and after farrowing, while the sow showed more interest in the object before than after farrowing. MCO use during the last week of lactation was higher in sows with a lower weight after weaning, suggesting a link between explorative motivation and energy status in the sow. These results indicate a need for further studies on how to best meet the possible exploratory need of sows during their time in the farrowing room.