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. 
Luo, L., Jansen, C. A., Bolhuis, J. E. et al. 2020. Early and later life environmental enrichment affect specific antibody responses and blood leukocyte subpopulations in pigs. Physiology & Behavior 217, 112799.

This study addressed the impact of early and later life environmental enrichment, and their combination, on specific antibody responses and peripheral blood leukocyte subpopulations in pigs. Pigs were kept in either barren (B1) or enriched...

Mertens, S., Gass, P., Palme, R. et al. 2020. Effect of a partial cage dividing enrichment on aggression-associated parameters in group-housed male C57BL/6NCrl mice. Applied Animal Behaviour Science 224, 104939.

Group-housing is highly important for social animals. Group-housing of male mice in captivity though often leads to aggression with partially disastrous consequences for the animals as well as for the quality of experimental data. In...

McAllister, B. B., Thackray, S. E., Garciá de la Orta, B. K. et al. 2020. Effects of enriched housing on the neuronal morphology of mice that lack zinc transporter 3 (ZnT3) and vesicular zinc. Behavioural Brain Research 379, 112336.

In the central nervous system, certain neurons store zinc within the synaptic vesicles of their axon terminals. This vesicular zinc can then be released in an activity-dependent fashion as an intercellular signal. The functions of...

Crawford, L. E., Knouse, L. E., Kent, M. et al. 2020. Enriched environment exposure accelerates rodent driving skills. Behavioural Brain Research 378, 112309.

Although rarely used, long-term behavioral training protocols provide opportunities to shape complex skills in rodent laboratory investigations that incorporate cognitive, motor, visuospatial and temporal functions to achieve desired goals. In the current study, following preliminary...

Qu, C., Xu, L., Shen, J. et al. 2020. Protection of blood-brain barrier as a potential mechanism for enriched environments to improve cognitive impairment caused by chronic cerebral hypoperfusion. Behavioural Brain Research 379, 112385.

Chronic cerebral hypoperfusion (CCH) is a common pathophysiological basis for Alzheimer’s Disease and vascular dementia in the early stages. It has been confirmed that blood-brain barrier (BBB) destruction is a key factor in CCH-related cognitive...

Menezes, J., Souto das Neves, B.-H., Gonçalves, R. et al. 2020. Maternal deprivation impairs memory and cognitive flexibility, effect that is avoided by environmental enrichment. Behavioural Brain Research 381, 112468.

Maternal deprivation (MD) causes cognitive deficits that persist until adulthood. Thereby, the environmental enrichment (EE) is widely used to increase brain plasticity. Here, pregnant female rats were used and their offspring were submitted to neonatal...

O’Leary, N. W., Byrne, D. T., Garcia, P. et al. 2020. Grazing cow behavior’s association with mild and moderate lameness. Animals 10(4), 661.

Accelerometer-based mobility scoring has focused on cow behaviors such as lying and walking. Accuracy levels as high as 91% have been previously reported. However, there has been limited replication of results. Here, measures previously identified...

Park, R. M., Foster, M., Daigle, C. L. 2020. A scoping review: The impact of housing systems and environmental features on beef cattle welfare. Animals 10(4), 565.

Housing systems and environmental features can influence beef cattle welfare. To date, little information has been synthesized on this topic. The aim of this scoping review was to examine the relationship between housing and welfare...

Çavuşoğlu, E., Rault, J.-L., Gates, R. et al. 2020. Behavioral response of weaned pigs during gas euthanasia with CO2, CO2 with butorphanol, or nitrous oxide. Animals 10(5), 787.

The swine industry is often forced to euthanize pigs in the first few weeks of life due to injuries, hernias, or unthriftiness. The majority of pigs are euthanized using carbon dioxide (CO2) gas asphyxiation but...

Frost, K., Shah, M., Leung , V. S. Y. et al. 2020. Aversion to desflurane and isoflurane in Sprague-Dawley rats (Rattus norvegicus). Animals 10(6), 950.

Carbon dioxide and isoflurane are widely used for killing rats, yet may not truly achieve “euthanasia”, because they elicit aversion. The inhalant anesthetic desflurane is faster acting than isoflurane, representing a potential refinement. Using an...

Watson, H. A study into viable wooden enrichment objects for Syrian hamsters. Animal Technology and Welfare 19(1), 86-88.

Failing to provide hamsters with a method to wear down their teeth can lead to detrimental behaviour such as bar chewing, and health issues, for example, overgrown teeth and tooth loss. However, hamsters use their...

Oralman, T. 2020. Confronting crunching: A refinement for the care of mice with the desire to crunch. Animal Technology and Welfare 19(1), 89-91.

‘Crunching’ is the term often used to describe the abnormal behaviour of mice that habitually crunch their pelleted diet, causing substrate levels to rise as the crumbs settle on the cage floor ultimately burying the...

Ballantine, A., Rodgers, D., Watts, C. et al. 2020. The cotton rat – a new challenge. Animal Technology and Welfare 19(1), 92-95.

This poster describes how the Animal Technologists at Envigo adapted their current practices and procedures for a new species at their laboratory: the cotton rat. The paper describes cotton rat biology and behaviour; housing; environmental...

Kauselmann, K., Krause, E. T., Glitz, B. et al. 2020. Short-term choice of fattening pigs for additional plant-based materials. Applied Animal Behaviour Science 226, 104975.

A major problem in conventional pig production systems is the occurrence of abnormal behaviours such as tail biting. Tail biting is a multifactorial problem, but it seems that a lack of proper enrichment materials prevents...

Zhang, L., McGlone, J. J. 2020. Scratcher preferences of adult in-home cats and effects of olfactory supplements on cat scratching. Applied Animal Behaviour Science 227, 104997.

Preferences for scratchers in adult cats have not yet been explored. Thirty-six adult cats were the subjects in three experiments to evaluate adult cat in-home preferences for scratchers, scratching materials, and the use of scratchers...

Park, R. M., Schubach, K. M., Cooke, R. F. et al. 2020. Impact of a cattle brush on feedlot steer behavior, productivity and stress physiology. Applied Animal Behaviour Science 228, 104995.

The aim of the present study was to investigate the impact of environmental enrichment (EE), in the form of a cattle brush, on feedlot cattle behavior, productivity and stress physiology. Steers were blocked by weight...

Améndola, L., Weary, D. M. 2020. Understanding rat emotional responses to CO2. Translational Psychiatry 10, 253.

The aim of this review is to summarize evidence regarding rat emotional experiences during carbon dioxide (CO2) exposure. The studies reviewed show that CO2 exposure is aversive to rats, and that rats respond to CO2...

Brekke, J., Scholz, J. 2020. Just hanging out: Elevating rat enrichment in small spaces. Laboratory Animal Science Professional 8(3) (May/June), 40-42.

This article describes how an Animal Care Technician at Mayo Clinic Rochester campus designed and created a novel enrichment item for rats: a ‘hammock’ made of PVC tunnels hung onto the lid of standard laboratory...

Buchanan, K. 2020. DIY: Foraging balls. Laboratory Animal Science Professional 8(3) (May/June), 51.

This article describes the steps for making a DIY guinea pig or rabbit cardboard foraging ball. Pictures are provided for each step as well as the completed ball. These cardboard foraging balls can be made...

Meagher, R. K., Strazhnik, E., von Keyserlingk, M. et al. 2020. Assessing the motivation to learn in cattle. Scientific Reports 10, 6847.

Cognitive challenges may provide a form of enrichment to improve the welfare of captive animals. Primates, dolphins, and goats will voluntarily participate in learning tasks suggesting that these are rewarding, but little work has been...

Blok, J., Black, D. A., Petersen, J. et al. 2020. Environmental enrichment rescues visually-mediated behavior in Ten-m3 knockout mice during an early critical period. Frontiers in Behavioral Neuroscience 14, 22.

Environmental enrichment (EE) has been shown to promote neural plasticity. Its capacity to induce functional repair in models which exhibit profound sensory deficits due to aberrant axonal guidance has not been well-characterized. Ten-m3 knockout (KO)...

Turner, P. V., Hickman, D. L., van Luijk, J. et al. 2020. Welfare impact of carbon dioxide euthanasia on laboratory mice and rats: A systematic review. Frontiers in Veterinary Science 7, 411.

Background: There has been increased concern about the suitability of CO2 as a method for euthanasia of laboratory mice and rats, including the potential discomfort, pain or distress that animals may experience prior to loss...

Luo, L., Reimert, I., Middelkoop, A. et al. 2020. Effects of early and current environmental enrichment on behavior and growth in pigs. Frontiers in Veterinary Science 7, 268.

Enriched environments are known to beneficially affect the behavior of pigs, as compared with barren pens. The influence of enrichment may, however, depend on pigs' early life housing experiences. The aim of this study was...

Reinhardt, V. (ed.) 2020. It’s Okay to Cry - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume V. Animal Welfare Institute, Washington, DC.

This is the 5th volume of selected discussions that took place on the electronic Laboratory Animal Refinement & Enrichment Forum between February 2016 and December 2019. The forum was created in October 2002; it allows...

Stevens, C., Finnegan, E., Clarkson, J. et al. 2020. Report of the 2019 RSPCA/UFAW Rodent Welfare meeting. Animal Technology and Welfare 19(2), 101-111.

The RSPCA/UFAW Rodent Welfare Group has held a one-day meeting every autumn for the last 26 years, so that its members can discuss current welfare research, exchange views on welfare issues, and share experiences of...