Piglet preference for infrared temperature and flooring

The aim of these experiments was to examine piglet preferences for different types of infrared temperatures and flooring at 24h of age. In Experiment 1, 10 piglets from each of 18 litters were distributed between three pairwise infrared temperature treatments (6 litters in each pairwise test): 26°C vs. 34°C, 26°C vs. 42°C or 34°C vs. 42°C. In Experiment 2, another 18 litters were tested in an identical set-up with infrared temperatures of 30°C vs. 34°C, 30°C vs. 38°C and 34°C vs. 38°C. In Experiment 3, another 18 new litters were used to test the choice between foam mattress vs. sawdust, foam mattress vs. water mattress, and sawdust vs. water mattress. The preference test apparatus consisted of a box with three compartments: two test compartments and one neutral compartment in the middle. The piglets were released in the neutral compartment, and they were then allowed to explore all compartments and choose where to settle. Each litter was video recorded for 1h and the piglets’ locations were scored every second minute. The results of Experiment 1 showed that the piglets had a significant preference for 42°C compared to 34°C (t=−5.3, P