How do we improve the lives of pigs?

Ever since the idea of ‘intensifying’ pig production began to be discussed there has been a lively debate surrounding the ‘rights’ and ‘wrongs’ of taking pigs from outside and housing them indoors. Abigail Woodsi has written an historical account of the development of intensive pig production where she has drawn on records to display the nuanced debate that paralleled the development of indoor pig keeping. Interestingly, much of the debate focused on the ‘natural’ pig. For example Ken Bolton, a pig farmer, wrote in 1956:ii

We have taken a roaming, rooting, earth-loving, open-air animal and put him into a stuffy or draughty place with a concrete floor under him and concrete walls all round him.

These sentiments have resurfaced many times since the modern day debate over animal welfare was initiated by Ruth Harrison’s book Animal Machines.iii For example, the Brambell Committee created in 1965 by the government to review evidence regarding animal welfare in intensive systems, reported:iv

In principle we disapprove of a degree of confinement of an animal which necessarily frustrates most of the major activities which make up its natural behaviour.

Much of animal welfare science which followed Brambell sought to investigate the extent to which farm animals such as pigs suffer from not being able to express their natural behaviours in intensive farming. For pigs, the results very much support Bolton’s intuitions. Science has shown that pigs have strong motivations to nest-build, to root and to be in close proximity to familiar individuals. Where these motivations are not met, pigs are stressed and often develop what are termed ‘behavioural problems’ such as biting each others’ tails and odd-looking repetitive behaviours called stereotypies. Scientists have also studied behaviours such as inquisitive exploration and play. Because these behaviours are often reduced by poor conditions (such as poor air quality) researchers have concluded that they can be used as sensitive indicators of good welfare conditions.

Welfare science should focus more on demonstrating that improving animal welfare also has benefits for humans.

Despite this scientific evidence globally, pigs are most often housed in conditions which prevent them behaving naturally, much as decried by Bolton. This is most apparent in growing pigs which are often housed on slatted floors (which allow faeces and urine to escape without manual labour), with solid walls, access to food and water and little else. Slatted floors mean that pigs cannot be given so-called enrichment materials such as straw, which are often used by pigs for rooting, exploration and play. In the EU there is a requirement to provide pigs with adequate enrichment but in commercial practice this is often limited to a dangling metal chain with a wooden block attached to the end.

So what is to be done? How can farmers be persuaded of the case for pigs being able to root, explore and play? Marian Dawkins, an eminent welfare scientist, wrote in 2012v that welfare science should perhaps focus less on providing evidence to support the animals’ perspective and focus more on demonstrating that improving animal welfare also has benefits for humans, and thus provide added incentive for change. What might be the advantages to us that could sway the argument in favour of allowing pigs to behave naturally? One line of research is to explore the outcomes of enrichment for pig health, and promisingly some recent research has indeed shown that keeping pigs in enriched conditions allows them to resist the effects of viral This could lead onto the use of enrichment as a means of reducing the use of antibiotics in pig production which is of immense importance to us all.vii

It seems to make common sense to keep animals in conditions where they can behave naturally but it may be that to facilitate this happening on a large scale we need to first demonstrate the benefits to humans.


This is part of CARNEVALE, a collaborative art-science project that explores animal welfare questions and the enthusiasm of pigs for investigative play. Click to see the rest.


Carnevale header


The Learned Pig


i. Woods, A. (2012) Rethinking the history of modern agriculture: British pig production, c. 1910–65. Twentieth Century British History 23: 165–191
ii. Bolton, K. (1954) Outdoor Pig Keeping. Ipswich: Pig Publications,16
iii. Harrison, R. (1964) Animal Machines: The New Factory Farming Industry. London: Vincent Stuart Ltd
iv. Brambell, F. (1965) Report of the Technical Committee to Enquire Into the Welfare of Animals Kept Under Intensive Livestock Husbandry Systems. London: HMSO
v. Dawkins, M.S. (2012) Why Animals Matter: Animal Consciousness, Animal Welfare, and Human Well-being. Oxford: OUP
vi. Dixhoorn, I.D.E., Reimert, I., Middlekoop, al (2016) Enriched housing reduces disease susceptibility to coinfection with porcine reproductive and respiratory virus and actinobacillus pleuropneumoniae in young pigs. PloS One 11(9): eo161832
vii. NHS Choices (2015) Antibiotic use in farm animals ‘threatens human health’.

Alistair Lawrence

Professor Alistair Lawrence, Chair of Animal Behaviour & Welfare (SRUC and University of Edinburgh) is interested in the concept of positive welfare both in terms of how we can measure the effects of pleasant experiences in animals but also how we promote the provision of positive welfare in practice.