Interactions of environmental conditions, day-night cycles, and growing periods on postural behavior of pigs

Abstract

Heat stress conditions can alter the physiology of animals, and these changes can be detrimental to their performance and health. The behavior of the animals is associated with their welfare and health. Understanding animals’ behavior in response to their environment is significant for better management. The objective of this study was to evaluate the behavioral response of pigs in terms of postural changes in different thermal conditions (thermoneutral and heat stress). A total of 26 growing pigs [(Largewhite x Landrace) x Duroc] were used for the evaluation. The effects of the thermal conditions, day-night cycles (daytime and nighttime), growing periods, and their interactions were determined using analysis of variance of a 2x2x3 Completely Randomized Design factorial. The results showed that 80% of the pigs were lying. It increased under heat stress condition and during the daytime. Lateral lying increased (p < 0.05) under heat stress condition, which was also affected by the day-night cycles and the growing period. High sternal lying (p < 0.05) was observed in the thermoneutral condition, and both groups had increasing (p < 0.05) sternal lying throughout growing periods. There was no significant difference (p > 0.05) in standing posture between groups. However, pigs in the thermoneutral condition had high standing at night and high standing during daytime in the heat stress condition. In conclusion, pigs behave differently based on their postural changes in different thermal conditions. Their behavior also differs between daytime and nighttime and throughout the growing period.