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. 
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...

Musk, G. C., Kershaw, H., He, B. 2019. Multiple refinements to the anaesthetic protocol for laparoscopic orthotopic kidney auto-transplantation in a pig model. Laboratory Animals 53(1), 72–78.

Fifty-four pigs (Sus scrofa, Large White cross) from a commercial pig farm were anaesthetised over a six-year period from October 2011. The procedural stages included initial instrumentation for intra-operative monitoring, laparoscopic nephrectomy, preparation of the...

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...

Heyworth, C., Owens, D. 2019. Eureka! Enhanced water recipe and enrichment for oocyte quality and embryo development in the African clawed frog (Xenopus laevis). Laboratory Animal Science Professional 7(1) (March), 43-45.

Husbandry staff set a goal to develop a health monitoring program for a Xenopus laevis colony that included not only specific pathogen freedom, but wellness. This article describes environmental enrichment and a water recipe for...

Marinath, L., Vaz, J., Kumar, D. et al. 2019. Drivers of stereotypic behaviour and physiological stress among captive jungle cat (Felis chaus Schreber, 1777) in India. Physiology & Behavior 210, 112651.

Zoos play a vital role in managing and conserving a wide range of threatened species and in enhancing their populations in natural habitats through captive breeding and reintroduction programmes. Most small felids are poor breeders...

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...

Edwards, K. L., Miller, M. A., Carlstead, K. et al. 2019. Relationships between housing and management factors and clinical health events in elephants in North American zoos. PLOS ONE 14(6), e0217774.

Elephants experience a number of health issues that can contribute to their well-being and survival. In managed populations, housing conditions and management practices can influence individual health, so potential risk factors associated with morbidity or...

Brown, J. L., Carlstead, K., Bray, J. D. et al. 2019. Individual and environmental risk factors associated with fecal glucocorticoid metabolite concentrations in zoo-housed Asian and African elephants. PLOS ONE 14(9), e0217326.

A recent large-scale welfare study in North America involving 106 Asian (Elephas maximus) and 131 African (Loxodonta africana) elephants at 64 accredited facilities identified links (i.e., risk factors) between zoo environmental factors and a number...

Rifkin, R. E., Grzeskowiak, R. M., Mulon, P-Y. et al. 2019. Use of a pressure-sensing walkway system for biometric assessment of gait characteristics in goats. PLOS ONE 14(10), e0223771.

The purpose of this study was to quantitatively assess gait characteristics and weight-bearing forces during ambulation in goats free of lameness using a pressure-sensing walkway as a biometric tool for stride, gait, and force analysis...

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...

Scott, N. L., LaDue, C. A. 2019. The behavioral effects of exhibit size versus complexity in African elephants: A potential solution for smaller spaces. Zoo Biology 38(5), 448-457.

Population-level analyses suggest that habitat complexity, but not necessarily space availability, has important welfare outcomes for elephants in human care. At the Dallas Zoo, the opening of a new exhibit complex allowed us to measure...

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...

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...

Gomes, D., McSweeney, L., Santos, M. 2019. Effects of environmental enrichment techniques on stereotypical behaviours of captive Sumatran tigers: A preliminary case study. Journal of Animal Behaviour and Biometeorology 7(4), 144-148.

Wild animals are maintained in Zoological facilities for purposes of education, conservation, research, and recreation. Several studies have proven that the surroundings of an animal's artificial habitat, as well as environmental enrichment techniques, are factors...

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...

Kallio, P. A, Janczak, A. M., Valros, A. E. et al. 2018. Case control study on environmental, nutritional and management-based risk factors for tail-biting in long-tailed pigs. Animal Welfare 27(1), 21-34.

A case control study with a questionnaire was carried out to compare feeding practices, diet composition, housing and management in 78 herds with or without a history of tail-biting in undocked pigs (Sus scrofa) in...

Hacker, C. E., Miller, L. J., Schulte, B. A. 2018. Examination of enrichment using space and food for African elephants (Loxodonta africana) at the San Diego Zoo Safari Park. Animal Welfare 27(1), 55-65.

Concern for elephant welfare in zoological facilities has prompted a number of exhibit and management modifications, including those involving enrichment. Knowledge of how these changes impact indicators of welfare, such as elephant movement and behaviour...

Cooke, G. M. 2018. Use of a translucent refuge for Xenopus tropicalis with the aim of improving welfare. Laboratory Animals 52(3), 304-307.

Xenopus tropicalis is an increasingly important animal model in a variety of biological research fields. In many countries legislation exists to promote and increase welfare wherever possible, including the ability to view animals during daily...

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...

Costa, R., Sousa, C., Llorente, M. 2018. Assessment of environmental enrichment for different primate species under low budget: A case study. Journal of Applied Animal Welfare Science 21(2), 185-199.

The 2011 European Union Zoo Inquiry presented evidence that most zoos fail to achieve adequate levels of nonhuman animal welfare. Appropriate environmental enrichment (EE) can play a role in the promotion of welfare. However, financial...

Maigrot, A., Hillmann, E., Briefer, E. 2018. Encoding of emotional valence in wild boar (Sus scrofa) calls. Animals 8(6), 85.

Measuring emotions in nonhuman mammals is challenging. As animals are not able to verbally report how they feel, we need to find reliable indicators to assess their emotional state. Emotions can be described using two...

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...

Shapiro, M. E., Shapiro, H. G., Ehmke, E. E. 2018. Behavioral responses of three lemur species to different food enrichment devices. Zoo Biology 37(3), 146–155.

Environmental enrichment is a tool used to promote the welfare and well‐being of captive animals by encouraging the display of species‐specific behaviors and reducing the stress or boredom induced by captive environments. Lemurs are highly...