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. 
Animal Welfare Institute. 2019. Rabbit enrichment items: Getting bang for the buck (and doe). AWI Quarterly 68(1) Spring, 24-25.

A recent discussion on the Laboratory Animal Refinement and Enrichment Forum (LAREF) focused on new enrichment ideas for rabbits. Contributors shared their experiences about which toys and treats get rave reviews from rabbits.

Ali, A. B. A., Campbell, D. L. M., Karcher, D. M. et al. 2019. Daytime occupancy of resources and flooring types by 4 laying hen strains in a commercial-style aviary. Journal of Veterinary Behavior 31, 59-66.

In response to consumer demands and legislative measures for improving hens' welfare, many laying hen producers are replacing conventional cages with aviaries. Aviary resources, such as nest boxes, litter areas, ledges, and perches, are intended...

Proops, L. Osthaus, B., Bell, N. et al. 2019. Shelter-seeking behavior of donkeys and horses in a temperate climate. Journal of Veterinary Behavior 32, 16-23.

Domestic donkeys descended from wild asses, adapted to the semi-arid climates of Africa, whereas domestic horses originate from more temperate areas of Eurasia. Despite this difference in evolutionary history, modern domestic equids can be found...

Durán, E., Churio, O., Lagos, J. et al. 2019. Development of edible environmental enrichment objects for weaned pigs. Journal of Veterinary Behavior 34, 7-12.

Studies on environmental enrichment for weaned pigs have predominantly focused on stimulating exploration through “nonedible toys.” The research on edible enrichment objects is very limited. For this reason, the aim of this study was to...

Cornale, P., Macchi, E., Miretti, S. et al. 2015. Effects of stocking density and environmental enrichment on behavior and fecal corticosteroid levels of pigs under commercial farm conditions. Journal of Veterinary Behavior 10(6), 569-576.

In intensive pig farming of Western and Southern Europe, welfare concerns are still often related to barren environments and crowded conditions. Pig producers need to balance the requirements to improve welfare conditions at farm with...

Heyworth, C. 2019. Revamping porcine enrichment. Laboratory Animal Science Professional 7(3) (September), 63-65.

Pigs may exhibit stereotypic behaviors due to lack of proper mental stimulation. Stereotypic behaviors include self-inflicted wounds, biting at the pen, polydipsia, cage destruction, and loud vocalizations. These behaviors may be alleviated with proper daily...

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...

Campderrich, I., Nazar, F. N., Wichman, A. 2019. Environmental complexity: A buffer against stress in the domestic chick. PLOS ONE 14(1), e0210270.

Birds kept in commercial production systems can be exposed to multiple stressors from early life and this alters the development of different morphological, immunological and behavioural indicators. We explore the hypothesis that provision of a...

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...

Ross, M., Garland, A., Harlander-Matauschek, A. et al. 2019. Welfare-improving enrichments greatly reduce hens' startle responses, despite little change in judgment bias. Scientific Reports 9, 11881.

Responses to ambiguous and aversive stimuli (e.g. via tests of judgment bias and measures of startle amplitude) can indicate mammals’ affective states. We hypothesised that such findings generalize to birds, and that these two responses...

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...

Fernandez, E. J., Kinley, R. C., Timberlake, W. 2019. Training penguins to interact with enrichment devices for lasting effects. Zoo Biology 38(6), 481-489.

The modern zoo has brought about two major advances in the behavioral welfare of their exhibited animals: (a) The use of environmental enrichment to promote naturalistic behaviors and (b) the use of training to improve...

Jung, L., Knierim, U. 2019. Differences between feather pecking and non-feather pecking laying hen flocks regarding their compliance with recommendations for the prevention of feather pecking – A matched concurrent case-control design. Applied Animal Behaviour Science 219, 104839.

Feather pecking (FP) is a multifactorial problem in all housing systems. Using a case-control design we wanted to determine a set of variables which may be decisive for a flock to become case or control...

Cox, R. J., Nol, P., Ellis, C. K. et al. 2019. Research with agricultural animals and wildlife. ILAR Journal 60(1), 66-73.

In fiscal year 2016, agricultural animals such as swine, sheep, goats, and cattle represented 10% of the 820 812 animals used in USDA-regulated research. In addition to traditional agricultural animals, research studies using captive wildlife...

Schmitt, V. 2019. Implementing portable touchscreen-setups to enhance cognitive research and enrich zoo-housed animals. Journal of Zoo and Aquarium Research 7(2), 50-58.

To understand the evolutionary development of cognition, comparing the cognitive capacities of different animal species is essential. However, getting access to various species with sufficient sample sizes can be very challenging. Zoos, housing large ranges...

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...

Hawkins, P., McBride, A., Paiba, G. et al. 2018. Report of the 2017 RSPCA/UFAW Rodent and Rabbit Welfare Group meeting. Animal Technology and Welfare 17(2), 75-83. [Meeting Report]

The RSPCA/UFAW Rodent (and now Rabbit) Welfare Group held a one-day meeting on 14 November 2017 in Weybridge, UK. The first session addressed meeting animals' needs and aiming for a 'good life', with the needs...

Pearson, K., Gant, J. 2018. Improving rabbit enrichment: Developing a rolling enrichment plan. Animal Technology and Welfare 17(2), 121-123.

A three-week enrichment preference study trialling different substrates, food and pen structures was carried out in three, group-housed female New Zealand White Rabbits (NZW). Preference results: structural - rabbits spent the most time with a...

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...

de Almeida A. C., Palme, R., Moreira, N. 2018. How environmental enrichment affects behavioral and glucocorticoid responses in captive blue-and-yellow macaws (Ara ararauna). Applied Animal Behaviour Science 201, 125-135.

Captive animals are susceptible to chronic stress due to restricted space, lack of hiding places, presence of visitors, or the lack of resources that promote physical and mental stimuli. In birds, chronic stress can promote...