Dim light does not reduce fighting or wounding of newly mixed pigs at weaning

Abstract

Pigs weaned at 27 d were mixed into groups of nine and exposed to constant illumination of 5 or 100 lx. Behavior was categorized every 10 min for 72 h and all fights were counted. Eating, drinking, lying and fighting patterns were similar in both light groups. The peak number of fights occurred 18–24 h post-weaning, concurrent with the major feeding episode. Ears and shoulders were scored for wounds 1 and 4 d after weaning; light intensity did not affect (P > 0.50) wound scores. Key words: Aggression, fight, light, pig, weaning, wound