Interaction of pen enrichment and sex on growth, physiology and behavioural responses of Windsnyer pigs.

Abstract

The broad objective of the study was to determine the interaction of pen enrichment and sex on growth performance, metabolite concentrations, physiological responses and behaviour of Windsnyer pigs. Forty–eight growing Windsnyer pigs, with an average initial body weight of 21.6 (± 9.01) kg, were used until a maximum average of 37.1 (± 11.58) kg of body weight. Four pigs were randomly assigned to either enriched or barren pens at a stocking density of 0.45 m2 /pig. The average daily feed intake (ADFI), average daily gain (ADG) and feed: gain (F: G) ratio, behavioural and physiological responses were estimated. Blood metabolites were also assessed. Pen enrichment did not affect ADG (P > 0.05). There was pen enrichment and sex interaction on ADFI (P < 0.05). Females in barren pens had higher ADFI than enriched females but ADFI in barren and enriched pens was similar for male pigs. Sex of pigs affected ADG and F: G ratio (P < 0.001), with male pigs growing faster than females. Pigs in barren pens had higher heart rates (P < 0.001) than those in enriched pens. There was an interaction of pen enrichment and sex on rectal temperature (P < 0.001). Females in enriched pens had higher rectal temperatures (P < 0.05) than females in barren pens. There was no interaction of pen enrichment and sex on feeding behaviour (P > 0.05). Time spent bullying was influenced (P < 0.05) by both pen enrichment and sex. Female pigs in barren pens spent more time on bullying than females in enriched pens. There was interaction of pen enrichment and sex on time spent lying down and walking (P < 0.05). Female pigs in enriched pens spent more time lying down than females in barren pens. Males in barren pens spent more time walking than males in enriched pens, while no effect of pen environment was observed in females. There was an interaction of pen enrichment and sex on time spent rolling, pivoting, tail biting and number of injuries (P < 0.05). It was concluded that enriched Windsnyer pigs housed at a stocking density of 0.45 m2/pig, particularly females perform better than those in barren pens Pen enrichment improves pig welfare by reducing the number of injuries and anti-social behaviours, particularly in female pigs.