Selection of bedded and unbedded areas by pigs in relation to environmental temperature and behaviour

Abstract In 2 experiments, groups of 3 pigs aged 4–8 weeks were given access to 2 sides of an experimental pen, one with straw bedding and one with a bare concrete floor. When resting or feeding, the 12 groups in Experiment 1 showed no consistent preference for the bedded or unbedded side. When active, the pigs were more often on the bedded side, especially at times when fresh straw was provided. The quantity of straw had no effect on these trends. In the second experiment, 10 groups tested at an ambient temperature of 18–21°C strongly selected the bedded side for resting, while those tested at 25–27°C usually selected the bare concrete. Feeding and general activity showed no clear relation to floor type. At the cooler temperatures, most groups dunged on the side that was not used for resting and feeding, but this structuring of the living space was not so apparent at the higher temperatures. The results indicate that the animals' preference for a bedded or concrete floor depends strongly on temperature. Under warm conditions, straw is likely to benefit pigs because of its recreational value but not as a means of improving comfort in the resting area.