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. 
Chan, K., Arellano, C., Horowitz, A. 2023. Here puppy, chew on this: Short-term provision of toys does not improve welfare in companion dogs. Animals 13(21), 3340.

Retail dog toys are often provided to companion animals to provide cognitive and physical stimu- lation and improve the animals’ quality of life. These toys, sometimes known as “enrichment toys”, have been shown to play...

Clark, F. E. 2023. In the zone: Towards a comparative study of flow state in primates. Animal Behavior and Cognition 10(1), 62–88.

Flow is an altered state of feeling ‘in the zone’ when fully absorbed in a challenge and is associated with positive affective state (feelings). Despite almost five decades of research, Flow has not yet been...

Englund, M. D., Cronin, K. A. 2023. Choice, control, and animal welfare: Definitions and essential inquiries to advance animal welfare science. Frontiers in Veterinary Science 10.

The ways in which humans can support good welfare for animals in their care is an ongoing subject of debate: some place emphasis on the animals’ physical health; others, on animals’ ability to live “natural...

Grandin, T. 2023. A practical approach to providing environmental enrichment to pigs and broiler chickens housed in intensive systems. Animals 13(14), 2372.

In Europe, regulations contain guidance to maintain high standards of animal welfare. In many parts of the world, large buyers for supermarkets or restaurants are the main enforcers of basic animal welfare standards. They can...

Gunter, L. M., Blade, E. M., Gilchrist, R. J. et al. 2023. The influence of brief outing and temporary fostering programs on shelter dog welfare. Animals 13(22), 3528.

Human interaction is one of the most consistently effective interventions that can improve the welfare of shelter-living dogs. Time out of the kennel with a person has been shown to reduce physiological measures of stress...

Jahn, K., Ley, J., DePorter, T. et al. 2023. How well do dogs cope with air travel? An owner-reported survey study. Animals 13(19), 3093.

It is estimated that 2 million domestic animals travel on commercial flights every year in the US alone and that dogs make up 58% of pets travelling worldwide. There has been little research on the...

Mählis, G., Kleine, A., Lüschow, D. et al. 2023. Clicker training as an applied refinement measure in chickens. Animals 13(24), 3836.

When using chickens in animal studies, the handling of these animals for sample collection or general examinations is considered stressful due to their prey nature. For the study presented here, plasma and salivary corticosterone as...

O’Brien, S. L., Cronin, K. A. 2023. The impacts of a commercial bubble curtain on zoo-housed African penguin (Spheniscus demersus) swimming behavior. Journal of Zoological and Botanical Gardens 4(3), 567–577.

Swimming is an important behavior for all penguin species. However, zoo-housed penguins typically do not swim as often as their wild counterparts, which may have consequences for their health and welfare. In an effort to...

van Zeeland, Y. R. A., Schoemaker, N. J., Lumeij, J. T. 2023. Contrafreeloading indicating the behavioural need to forage in healthy and feather damaging Grey parrots. Animals 13(16), 2635.

Contrafreeloading (CFL) is a concept that describes the preference of an animal to work for food even when identical food is freely available, and reflects an intrinsic motivation to engage in foraging-related activities. However, altered...

Zhao, S., Cui, W., Yin, G. et al. 2023. Effects of different auditory environments on behavior, learning ability, and fearfulness in 4-week-old laying hen chicks. Animals 13(19), 3022.

Environmental enrichment can improve animal welfare. As a method of environmental enrichment, the effect of different auditory stimulations on the behavior response and welfare of laying hen chicks has yet to be investigated. Therefore, this...

Association of Primate Veterinarians. 2023. Association of Primate Veterinarians guidelines for domestic transport of nonhuman primates in biomedical research. JAALAS 62(3), 198-201.

The purpose of this guidance document is to provide veterinarians and other individuals associated with domestic transportation of nonhuman primates (NHP) with an overview of the critical aspects of the process including planning, execution, and...

Deugan, C. R., Gross, A. A. 2023. Nonhuman primate enrichment evaluation program. Laboratory Animal Science Professional 11(2) (March/April), 46-49.

Noting that it is typical for enrichment devices to be approved by a committee and understanding that this is paramount for animal safety, we began to think outside the box and seek additional ways to...

Clark, F. E., Chivers, L., Pearson, O. 2023. Material and food exploration by zoo-housed animals can inform cognition and enrichment apparatus design. Zoo Biology 42(1), 26–37.

To robustly study zoo animal cognition and provide effective enrichment, we must provide animals with carefully designed apparatus made from appropriate (safe, attractive, practical) materials. However, all too often, this design phase is overlooked or...

Greene, L. K., Andriambeloson, J.-B., Blanco, M. B. et al. 2023. Forest access restores foraging and ranging behavior in captive sifakas. Zoo Biology 42(2), 209–222.

Captive wildlife benefit from ecologically informed management strategies that promote natural behaviors. The Duke Lemur Center has pioneered husbandry programs rooted in species’ ecology for a diversity of lemurs, including housing social groups in multiacre...

Hanh, H. Q., Phuong, N. T., Tien, N. D. et al. 2023. Effects of stocking density in group cages on egg production, profitability, and aggressive pecking of hens. Journal of Applied Animal Welfare Science 26(3), 374–385.

There is an increasing concern about welfare issues related to battery cages, which are commonly used in Vietnam, and requires a modified cage that improves hen welfare while retaining its economic and management advantages. We...

Mitin, H., Idrus, Z., Meng, G. Y. et al. 2023. Effects of positive human contact on fear and physiological stress responses in Pekin ducks (Anas platyrhynchos domesticus) subjected to crating and transport. Applied Animal Behaviour Science 269, 106108.

A growing body of research shows that farm animals frequently seek and enjoy human interaction. However, there is a lack of information on how positive human contact affects ducks’ stress and fear responses. An experiment...

Truax, J., Vonk, J. 2023. Silence is golden: Auditory preferences in zoo-housed gorillas. Journal of Applied Animal Welfare Science 26(3), 404–419.

Enrichment is presented to improve the welfare of captive animals but sound is frequently presented with the assumption that it is enriching without assessing individuals’ preferences. Typically, presented sounds are unnatural and animals are unable...

Wowk, Z. M., Behie, A. M. 2023. The influence of olfactory enrichment on the behavior of two captive New World primates: Black-capped capuchin (Sapajus apella) and common marmoset (Callithrix jacchus). Zoo Biology 42(2), 231–242.

Environmental enrichment is an animal husbandry principle that seeks to provide the stimuli necessary for the optimal physiological and psychological well-being of animals. Due to primates having highly developed visual systems, there have been limited...

Zhao, S., Zhang, R., Li, C. et al. 2023. The effect of short-term classical music stimulus on behavior and tonic immobility reaction of pullets. Journal of Applied Animal Welfare Science 26(3), 386–392.

The purpose of this study was to investigate the effect of short-term stimulation of classical music on the behavior of pullets and to explore whether classical music as an auditory enrichment factor reduces the fear...

LaFollette, M. R., Cloutier, S., Brady, C. M. et al. 2023. Benchmarking enrichment efforts in the US & Canada across species and enrichment categories. JAALAS 62(4), 303–316.

Enrichment is important for animal welfare and data quality. Provision of enrichment opportunities varies between species and enrichment category. However, data benchmarking these differences does not exist. Our objective was to characterize enrichment provision and...

Brereton, J., Rose, P. 2022. An evaluation of the role of 'biological evidence' in zoo and aquarium enrichment practices. Animal Welfare 31(1), 13-26.

Evidence-based approaches are key to advancing all areas of zoo and aquarium practice. Output from empirical study must be disseminated to those within the industry so that results can support changes to husbandry and management...

Hunt, R. L., Whiteside, H., Prankel, S. 2022. Effects of environmental enrichment on dog behaviour: Pilot study. Animals 12(2), 141.

Environmental enrichment (EE) can be used to enhance the environment of various animals. The aim of this pilot study was to determine the effects of seven EE activities (Bonding, Bubble machine, Conspecific play, Interactive toy...

King, T., Flint, H. E., Hunt, A. B. G. et al. 2022. Effect of music on stress parameters in dogs during a mock veterinary visit. Animals 12(2), 187.

Veterinary visits can be stressful for dogs, but how their wellbeing changes during a visit is not well understood. Music therapy has been successfully used in clinical practice to alleviate stress and anxiety in people...

Taylor, P. S., Hemsworth, P. H., Rault, J.-L. 2022. Environmental complexity: Additional human visual contact reduced meat chickens’ fear of humans and physical items altered pecking behavior. Animals 12(3), 310.

Increased environmental complexity can improve animal welfare, depending on the resources provided and use by the animal. We provided chickens either with physical items that posed no biosecurity risk and were inexpensive (balls, chains, perches...

Campbell, D. L. M., Belson, S., Dyall, T. R. et al. 2022. Impacts of rearing enrichments on pullets’ and free-range hens’ positive behaviors across the flock cycle. Animals 12(3), 280.

Enrichment during the indoor rearing of pullets destined for free-range systems may optimize pullet development including increasing motivated natural behaviors (termed ‘positive behaviors’) including foraging, dust bathing and chick play. Hy-Line Brown® chicks (n =...