The Effect of Substrate-Enriched and Substrate-Impoverished Housing Environments On the Diversity of Behaviour in Pigs

Abstract

In intensive farming situations, growing animals are housed in relatively barren environments. The lack of opportunity to perform substrate-interactive and manipulative behaviour patterns may affect the expression and organization of these behaviours. However, making direct comparisons of the behaviour expressed in environments of differing physical complexity is difficult. In this experiment a relative diversity index was used to compare the behavioural repertoires of pigs housed in two different environments for a period of five months. One group of pigs (substrate-enriched) had straw, forest bark and branches added to the standard pens and the other group (substrate-impoverished) did not. The pigs were individually housed, and their behaviour was focal sampled in these pens on one day each month. It was shown that the relative diversity of manipulative behaviour shown by the pigs in the substrate-impoverished environment was lower than in the pigs in the substrate-enriched environment (p < 0.05). The relative diversity of the whole behavioural repertoire shown by the pigs in the substrate-impoverished environment also tended to be lower than that in the substrate-enriched environment (p = 0.06). It is concluded that this may be due to a difference between the two groups in motivation to interact with and manipulate objects, or a function of the manipulable quality of the substrates available to them. Alternatively, exposure to substrate-impoverished environments may interfere with the ability to express manipulative behaviour. Both situations pose a threat to the welfare of growing pigs resident in barren environments.

Doing nothing and what it looks like: inactivity in fattening cattle

“…The number of distinct detected combinations was higher for INTENSIVE and SEMI than for PASTURE. One would expect animals in more intensive systems to show fewer different postures in line with studies showing that behavioural diversity is reduced in barren compared to enriched systems (e.g., Haskell et al, 1996;Powell, 1995;Wemelsfelder et al, 2000). However, these studies focused on active behaviour, and not on co-occurring postures.…”

“…Most studies so far have focused on inactivity levels in barren compared to enriched environments. Studies with pigs, mice and minks housed in either barren environments (e.g., slatted floor pens for fattening pigs, Bolhuis et al, 2006) or enriched environments (e.g., pen with some sort of substrate, Bolhuis et al, 2006, andextra space, Beattie et al, 2000) found that under barren conditions, animals spend more time being inactive (Beattie et al, 2000;Bolhuis et al, 2006;Fureix et al, 2016;Haskell et al, 1996;Meagher, Campbell & Mason, 2017;Meagher & Mason, 2012). Moreover, pigs and mink experiencing a change from enriched to barren conditions show more inactive behaviour when compared to animals housed in barren conditions (Bolhuis et al, 2006;Meagher et al, 2013).…”

Spatial learning in pigs: effects of environmental enrichment and individual characteristics on behaviour and performance

“…In commercial pig husbandry, however, growing pigs are frequently housed in rather 'barren', stimulus-poor environments that may impose constraints on the development and expression of normal species-speciWc behaviour (Schouten 1986;Haskell et al 1996;Wemelsfelder et al 2000) and, possibly, cognitive abilities . Particularly the lack of a suitable substrate as an outlet for the performance of exploratory activities, such as nosing, rooting and chewing, negatively aVects pig behaviour.…”

Effects of strawbedding on physiological responses to stressors and behavior in growing pigs

“…Several studies have compared the behavior of pigs housed under intensive conditions with the behavior of pigs housed in a more enriched environment, such as pens provided with substrate (12) or pens with increased floor space and substrate (2,3,29). Pigs housed in these enriched pens spent more time in exploration and had more diverse behavior patterns compared to pigs housed under intensive conditions (2,12,29) and showed less restlessness during rearing and when adult (29).…”

“…Pigs housed in these enriched pens spent more time in exploration and had more diverse behavior patterns compared to pigs housed under intensive conditions (2,12,29) and showed less restlessness during rearing and when adult (29). Enriched housed pigs showed less manipulative social behaviors such as nosing, biting and massaging littermates (2,3,29).…”