Refinement Database

Database on Refinement of Housing, Husbandry, Care, and Use of Animals in Research

This database, created in 2000, is updated every four months with newly published scientific articles, books, and other publications related to improving or safeguarding the welfare of animals used in research.

Tips for using the database:

  • This landing page displays all of the publications in the database.
  • Use the drop-down menus to filter these publications by Animal Type, Setting, and/or Topic.
  • Clicking on a parent category (e.g., Rodent) will include publications relating to all the items in that category (e.g., Chinchilla, Gerbil, Guinea Pig, etc.).
  • You may also add a keyword to further narrow your search.
  • Please note that at this time, only publications dated 2010 or later (with some exceptions) can be filtered by Animal Type and Topic, and only publications dated 2020 or later (with some exceptions) can be filtered by Setting. Most publications older than 2010 can only be searched by keyword. 
Bracke, M. B. M., Koene, P. 2019. Expert opinion on metal chains and other indestructible objects as proper enrichment for intensively-farmed pigs. PLOS ONE 14(2), e0212610.

EC Directive 2001/93 requires that all pigs have access to proper investigation and manipulation materials. Intensively farmed pigs in Europe are frequently provided with a short metal chain with or without an indestructible object attached...

Morgan, L., Itin-Shwartz, B., Koren, L. et al. 2019. Physiological and economic benefits of abandoning invasive surgical procedures and enhancing animal welfare in swine production. Scientific Reports 9, 16093.

Food-animal welfare is a major ethical and social concern. Pork is the most consumed meat worldwide, with over a billion pigs slaughtered annually. Most of these pigs routinely undergo painful surgical procedures (surgical castration, tail...

Middelkoop, A., Costermans, N., Kemp, B. et al. 2019. Feed intake of the sow and playful creep feeding of piglets influence piglet behaviour and performance before and after weaning. Scientific Reports 9, 16140.

Creep feed intake is variable and may be partly homeostatically and exploratory driven. We studied effects of maternal feed restriction and a ‘play-feeder’ on piglet behaviour and performance. 37 Litters received creep feed in a...

Cecchin, D., Torres Campos, A., Sodré Amaral, P. I. et al. 2019. Behavior of swine hosted in facilities with different construction typologies. Journal of Animal Behaviour and Biometeorology 7(1), 6-10.

The aim of this study was to analyze the behavior of pigs housed in facilities with different building typologies in terms of the floor and partitions. Two treatments were compared: a pen containing an area...

Špinka, M. 2019. Animal agency, animal awareness and animal welfare. Animal Welfare 28(1), 11–20.

In nature, animals need to actively engage with the environment in order to prosper in survival and reproduction. Hence, agency is a central adaptive characteristic of animal life. In this paper, I propose that from...

Luo, L., Reimert, I., de Haas, E. N. et al. 2019. Effects of early and later life environmental enrichment and personality on attention bias in pigs (Sus scrofa domesticus). Animal Cognition 22(6), 959–972.

We investigated effects of early and later life housing on attention bias, as an indicator of affective state, in pigs differing in coping style [reactive (LR) vs. proactive (HR)]. Pigs (n = 128) in barren or enriched...

Fels, M., Lüthje, F., Faux-Nightingale, A. et al. 2018. Use of space and behavior of weaned piglets kept in enriched two-level housing system. Journal of Applied Animal Welfare Science 21(3), 267-282.

In this study, the possibility of introducing an elevated platform to a piglet pen was explored as a way of increasing available space and creating functional areas. On the platform, nine different manipulable materials were...

Ralph, C., Hebart, M., Cronin, G. 2018. Enrichment in the sucker and weaner phase altered the performance of pigs in three behavioural tests. Animals 8(5), 74.

We tested the hypothesis that provision of enrichment in the form of enrichment blocks during the sucker and weaner phases would affect the behaviour of pigs. We measured the performance of pigs in an open...

Backus, B. L., McGlone, J. J. 2018. Evaluating environmental enrichment as a method to alleviate pain after castration and tail docking in pigs. Applied Animal Behaviour Science 204, 37-42.

Castration and tail docking are common management practices performed on commercial swine farms in the US and around the world to reduce adverse behaviors and the occurrence of boar taint. However, these practices themselves are...

Yang, C.-H., Ko, H.-L., Salazar, L. C. et al. 2018. Pre-weaning environmental enrichment increases piglets’ object play behaviour on a large scale commercial pig farm. Applied Animal Behaviour Science 202, 7-12.

Environmental enrichment is a legal requirement for European pig farms. The suitability of enrichment materials for neonatal pigs is understudied and has not been tested in commercial settings. This study investigates the effect of hanging...

Rosvold, E. M., Newberry, R. C., Framstad, T. 2018. Nest-building behaviour and activity budgets of sows provided with different materials. Applied Animal Behaviour Science 200, 36-44.

Domestic sows are still highly motivated to build a nest before farrowing. Many pig houses have slurry systems that do not allow use of long straw or other bulky materials that could block the drains...

Wondrak, M., Conzelmann, E., Veit, A. et al. 2018. Pigs (Sus scrofa domesticus) categorize pictures of human heads. Applied Animal Behaviour Science 205, 19-27.

Scientists as well as farmers are increasingly interested in the mental capacities of pigs. Recent research has revealed surprising cognitive abilities, such as episodic memory, intentional deception and even theory of mind. Still, our knowledge...

Colpoys, J. D., Johnson, A. K., Gabler, N. K. 2018. The efficacy of novel rope flavours as environmental enrichment for stalled gilts. Animal Welfare 27(4), 351-356.

The objective of this study was to evaluate the use of flavoured ropes as environmental enrichment for individually housed pigs (Sus scrofa). A 4 × 4 Latin square experimental design was utilised to evaluate the...

Schild, S.-L. A., Rangstrup-Christensen, L., Bonde, M. et al. 2018. The use of a shaded area during farrowing and lactation in sows kept outdoors. Applied Animal Behaviour Science 209, 22-29.

The hut temperature in outdoor pig production during summer can exceed the upper critical temperature of lactating sows. Therefore, sows may experience hyperthermia, a condition which has several adverse consequences for the welfare of both...

Brown, S.M., Bush, S.J., Summers, K.M. et al. 2018. Environmentally enriched pigs have transcriptional profiles consistent with neuroprotective effects and reduced microglial activity. Behavioural Brain Research 350, 6-15.

Environmental enrichment (EE) is widely used to study the effects of external factors on brain development, function and health in rodent models, but very little is known of the effects of EE on the brain...

Perdue, B. M., Beran, M. J., Washburn, D. A. 2018. A computerized testing system for primates: Cognition, welfare, and the Rumbaughx. Behavioural Processes 156, 37-50.

Innovations in apparatus technology come about for a variety of reasons such as the need to use the same methodology with various species, the opportunity to present dynamic and carefully controlled stimuli, the goal of...

Mkwanazi, M. V., Kanengoni, A. T., Chimonyo, M. 2018. Pen enrichment and sex interaction on growth performance and metabolite concentrations of autochthonous Windsnyer pigs kept in a high stocking density. Canadian Journal of Animal Science 98(4), 826-832.

The objective of the study was to determine the interaction of pen enrichment and sex on growth performance and blood metabolite concentrations of Windsnyer pigs. Forty-eight growing Windsnyer pigs of both sexes, with an average...

Bulens, A., Van Beirendonck, S., Van Thielen, J. et al. 2018. Rearing finishing pigs with intact tails: Do they benefit from an enriched environment? Journal of Veterinary Behavior 24, 1-8.

In an attempt to prevent tail biting in pigs, tail docking is often done. This management procedure is painful for the pigs, so the question arises whether pigs can be raised with intact tails and...

Heyworth, C., Olivo, D. 2018. Environmental and psychological enrichment for NHPs reimagined and repurposed. Laboratory Animal Science Professional 5(4) (December), 39-43.

This article describes creative enrichment ideas for nonhuman primates, including celery stalks embedded with seeds; paper rolled into tubes, braided and filled with fruit and seeds; pineapple crowns loaded with treats; dry spaghetti noodles coated...

Machado, S. P., Caldara, F. R., Foppa, L. et al. 2017. Behavior of pigs reared in enriched environment: Alternatives to extend pigs attention. PLOS ONE 12(1), e0168427.

Three trials were carried out in a completely randomized design aiming to assess the behavior of pigs in growth phase in enriched environments. Trial 1 evaluated the effects of frequency of availability of environmental enrichment...

Winfield, J., Macnamara, G., Macnamara, B. et al. 2017. Environmental enrichment for sucker and weaner pigs: The effect of enrichment block shape on the behavioural interaction by pigs with the blocks. Animals 7(12), 91.

This experiment tested the effect of enrichment-block shape on oro-nasal contact by young pigs, and possible habituation to the blocks. Nineteen litters (197 piglets) were randomly allocated to one of three block-shape treatments: Cube, Brick...

Vermeer, H., Dirx-Kuijken, N., Bracke, M. 2017. Exploration feeding and higher space allocation improve welfare of growing-finishing pigs. Animals 7(5), 36.

Lack of environmental enrichment and high stocking densities in growing-finishing pigs can lead to adverse social behaviors directed to pen mates, resulting in skin lesions, lameness, and tail biting. The objective of the study was...

Backus, B. L., Sutherland, M. A., Brooks, T. A. 2017. Relationship between environmental enrichment and the response to novelty in laboratory-housed pigs. JAALAS 56(6), 735-741.

Environmental enrichment is the enhancement of the physical or social environment in which an animal lives with the goal to improve its quality of life. Our objective was to investigate the effect of providing environmental...

Brown, S. M., Peters, R., Lawrence, A. B. 2017. Up-regulation of IGF-1 in the frontal cortex of piglets exposed to an environmentally enriched arena. Physiology & Behavior 173, 285-292.

Environmental enrichment (EE) is widely used in the life sciences to study effects of environment on the brain. In pigs, despite lack of EE being a key welfare issue there is little understanding of brain...

Palmer, S. 2017. Rescue-Enrich-Release: The environmental enrichment program for three species of captive primates at Colobus. Canopy 17(2), 27-30.

It is widely known that the psychological wellbeing of captive animals can become compromised by a captive environment that lacks proper environmental stimulation. Environmental enrichment programs have become the norm in captive environments yet research...