Sows that are housed in groups establish a social hierarchy to gain preferential access to needed resources, such as feed. The establishment and maintenance of this social hierarchy may lead to reduced welfare and performance for certain sows. Therefore, the purpose of this study was to determine whether infrared thermography, feeding behavior, and heart rate variability measurement could identify the social hierarchy. In the future, the ability to automatically detect the social hierarchy within group housed pens using technology may give a producer the ability to mitigate any hierarchy-related welfare and performance issues on their own farm. Our results show that feeding behavior collected by an automated feeding system may be a promising tool for future social hierarchy detection. Additionally, measures related to changes in heart rate over time are capable of identifying high- and low-ranked sows when the measures are collected before sows are moved into groups. Therefore, technologies capable of measuring feeding behavior and changes in heart rate over time may be promising for future automated detection of the sow social hierarchy.

Read the full article in the Journal of Animal Science.