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. 
Zentall, T. R. 2021. Effect of environmental enrichment on the brain and on learning and cognition by animals. Animals 11(4), 973.

The humane treatment of animals suggests that they should be housed in an environment that is rich in stimulation and allows for varied activities. However, even if one’s main concern is an accurate assessment of...

Hall, B. A., McGill, D. M., Sherwen, S. L. et al. 2021. Cognitive enrichment in practice: A survey of factors affecting its implementation in zoos globally. Animals 11(6), 1721.

Information on the practical use of cognitive enrichment in zoos is scarce. This survey aimed to identify where cognitive enrichment is being used while identifying factors that may limit its implementation and success. Distributed in...

Fernandez, E. J., Upchurch, B., Hawkes, N. C. 2021. Public feeding interactions as enrichment for three zoo-housed elephants. Animals 11(6), 1689.

The past few decades have seen increased interest in studies examining the welfare of elephants and animal–visitor interactions. One understudied area for both pursuits is the impact of public feeding interactions. Our study examined the...

dos Santos Gauy, A. C., Bolognesi, M. C., Martins, G. D. et al. 2021. Preference and motivation tests for body tactile stimulation in fish. Animals 11(7), 2042.

We tested whether territorial fish (Nile tilapia) perceive body tactile stimulation as a positive or negative resource. Individual male fish were placed for eight days in an aquarium containing a rectangular PVC frame, which was...

Zhang, Z., Fu, Y., Zhang, Z. et al. 2021. A comparative study on two territorial fishes: The influence of physical enrichment on aggressive behavior. Animals 11(7), 1868.

Intraspecific aggression is detrimental to body/fin damage, physiological stress, and other problems in aquaculture. Environmental enrichment has been proposed to have positive effects on fish aggressive behavior, physiological stress, and fish welfare, but there are...

Polanco, A., Meagher, R., Mason, G. 2021. Boredom-like exploratory responses in farmed mink reflect states that are rapidly reduced by environmental enrichment, but unrelated to stereotypic behaviour or ‘lying awake’. Applied Animal Behaviour Science 238, 105323.

Consistent with boredom, prior work has found that mink raised in non-enriched (NE) or enriched (E) conditions differ in their motivations to seek stimulation: NE mink spent more time oriented towards and in contact with...

Zhang, C., Juniper, D. T., Meagher, R. K. 2021. Effects of physical enrichment items and social housing on calves’ growth, behaviour and response to novelty. Applied Animal Behaviour Science 237, 105295.

The objective of this study was to determine the effects of social housing, the provision of physical enrichment, and the interaction between the two on calf growth, behaviour and fearfulness. Forty-eight calves were randomly allocated...

Lemos de Figueiredo, R., Hartley, M., Fletcher, A. W. 2021. Assessing the behaviour, welfare and husbandry of mouse deer (Tragulus spp.) in European zoos. Applied Animal Behaviour Science 237, 105283.

Mouse deer are primitive, forest ungulates found in Asia and Africa. Both the lesser mouse deer (Tragulus javanicus) and the Philippine mouse deer (T. nigricans) are managed in European zoos, but inconsistent breeding success between...

Hoehfurtner, T., Wilkinson, A., Nagabaskaran, G. et al. 2021. Does the provision of environmental enrichment affect the behaviour and welfare of captive snakes? Applied Animal Behaviour Science 239, 105324.

There is a wealth of evidence demonstrating the benefits of environmental enrichment across a range of different animal species. However, there is comparatively little such research into the effect of enrichment provision on captive reptiles...

Arre, A. M., Horschler, D. J. 2021. Swimming and diving as social play in juvenile rhesus macaques (Macaca mulatta). Behaviour 158(6), 529-546.

Although play is ubiquitous throughout the animal kingdom, and in primates especially, the ultimate explanations and proximate mechanisms of play are not well understood. Previous research proposes that primate play may be important for the...

Alnes, I. B., Jensen, K. H., Skorping, A. et al. 2021. Ontogenetic change in behavioral responses to structural enrichment from fry to parr in juvenile Atlantic salmon (Salmo salar L.). Frontiers in Veterinary Science 8, 638888.

Enrichment is widely used as a tool for studying how changes in environment affect animal behavior. Here, we report an experimental study investigating if behaviors shaped by stimuli from environmental enrichment depending on the stage...

Malchow, J., Schrader, L. 2021. Effects of an elevated platform on welfare aspects in male conventional broilers and dual-purpose chickens. Frontiers in Veterinary Science 8, 660602.

To avoid killing day-old male chicks, one possibility is to keep dual-purpose chicken strains. Here, the hens were kept for egg production, and the roosters were kept for meat production. Both sexes had moderate performances...

Alvarez Ramírez, L., Mejía Huerta, N. G., Sánchez Cervantes, A. 2021. Artificial shade effects on behavior and body weight of pregnant grazing red deer (Cervus elaphus). Journal of Veterinary Behavior 44, 32-39.

The study aimed to determine whether artificial shade influences grazing behavior and body weight of pregnant female red deer. Two groups of pregnant does were grazed in enclosures with shade (WS, n = 23), or non-shaded enclosures...

Lambert, K. 2021. DIY: Acacia gum sealed paper straws. Laboratory Animal Science Professional 9(3) (May/June), 37.

This DIY snack is great for NHP and can be customized in a variety of ways.

Hollandt, T., Baur, M., Wöhr, A.-C. 2021. Animal-appropriate housing of ball pythons (Python regius)—Behavior-based evaluation of two types of housing systems. PLOS ONE 16(5), e0247082.

Considering animal welfare, animals should be kept in animal-appropriate and stress-free housing conditions in all circumstances. To assure such conditions, not only basic needs must be met, but also possibilities must be provided that allow...

Albanese, V., Kuan, M., Accorsi, P.A. et al. 2021. Evaluation of an enrichment programme for a colony of long-tailed macaques (Macaca fascicularis) in a rescue centre. Primates 62(4), 585-593.

Long-tailed macaques are highly social primates that are commonly used in biomedical research as animal models. The aim of this study was to evaluate the effects of different kinds of enrichment on the behaviour and...

Bodenham, R. 2021. Introducing the swing ball! RATEL (Journal of the Association of British and Irish Wild Animal Keepers) 48(1), 4-7.

A short observational study was carried out on Chester Zoo’s male jaguar and its pack of 14 bush dogs to see if any behavioural changes were found with each species when they were engaging with...

Norman, K. I., Weeks, C. A., Tarlton, J. F. 2021. Rearing experience with ramps improves specific learning and behaviour and welfare on a commercial laying farm. Scientific Reports 11(1), 8860.

To access resources in commercial laying houses hens must move between levels with agility to avoid injury. This study considered whether providing ramps during rear improved the ability of birds to transition between levels. Twelve...

Learmonth, M. J., Sherwen, S., Hemsworth, P. H. 2021. Assessing preferences of two zoo-housed Aldabran giant tortoises (Aldabrachelys gigantea) for three stimuli using a novel preference test. Zoo Biology 40(2), 98-106.

Recent research has uncovered many complex cognitive traits and affective processes in many reptile species, such as the ability to make choices that are rewarding or pleasurable. The investigation herein was initiated after many years...

Carter, M., Sherwen, S., Webber, S. 2021. An evaluation of interactive projections as digital enrichment for orangutans. Zoo Biology 40(2), 107-114.

Digital technologies are increasingly being incorporated into the provision of enrichment for captive primates, ranging from the ad-hoc use of iPads to specifically designed hardware installed in the design of new exhibits. In this article...

Robbins, R. L., Sheridan, J. 2021. Effect of enclosure expansion on the activity budgets of eastern black-and-white colobus monkeys, Colobus guereza. Zoo Biology 40(2), 115-123.

Behavior is one of the most observable and informative indicators of animal welfare. This study used behavioral observation methodologies to evaluate the impact of an enclosure expansion on the activity budgets of a group of...

Bannister, C. C., Thomson, A. J. C., Cuculescu-Santana, M. 2021. Can colored object enrichment reduce the escape behavior of captive freshwater turtles? Zoo Biology 40(2), 160-168.

The effect of environmental enrichment on the behavior and welfare in captivity of reptiles and of freshwater turtles in particular, which are popular aquarium and pet species, is very little studied compared to other taxa...

Campbell, D. L. M., Whitten, J. M., Slater, E. et al. 2021. Rearing enrichments differentially modified hen personality traits and reduced prediction of range use. Animal Behaviour 179, 97-109.

Domestic fowl have been demonstrated to individually differ in personality, dictating reactions to environmental stimuli. Free-range chickens, Gallus gallus domesticus, show individual range use variation, which may be related to personality differences. Enrichment can also...

Anderson, M. G., Campbell, A. M., Crump, A. et al. 2021. Effect of environmental complexity and stocking density on fear and anxiety in broiler chickens. Animals 11(8), 2383.

Barren housing and high stocking densities may contribute to negative affective states in broiler chickens, reducing their welfare. We investigated the effects of environmental complexity and stocking density on broilers’ attention bias (measure of anxiety)...

Snowdon, C. T. 2021. Animal signals, music and emotional well-being. Animals 11(9), 2670.

Playing music or natural sounds to animals in human care is thought to have beneficial effects. An analysis of published papers on the use of human-based music with animals demonstrates a variety of different results...