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. 
Krönke, F., Xu, L. 2023. Sensory stimulation as a means of sustained enhancement of well-being in leopard geckos, Eublepharis macularius (Eublepharidae, Squamata). Animals 13(23), 3595.

Although the private keeping of reptiles has boomed in most western countries since the millennium, studies dealing with the recognition and promotion of welfare in these reptiles seem to represent a blind spot of scientific...

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...

Montalcini, C. M., Petelle, M. B., Toscano, M. J. 2023. Commercial hatchery practices have long-lasting effects on laying hens’ spatial behaviour and health. PLOS ONE 18(12), e0295560.

The commercial hatchery process is globally standardized and exposes billions of day-old layer chicks to stress every year. By alleviating this early stress, on-farm hatching is thought to improve animal welfare, yet little is known...

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...

Wang, C., Yang, C., Zeng, Y. et al. 2023. GnRH-immunocastration: An alternative method for male animal surgical castration. Frontiers in Veterinary Science 10.
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...

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...

de Oliveira sans, E. C., Dahlke, F., Freitas Federici, J. et al. 2023. Welfare of broiler chickens in Brazilian free-range versus intensive indoor production systems. Journal of Applied Animal Welfare Science 26(4), 505–517.

We compared broiler chicken welfare in free-range (FR) and intensive indoor (IN) systems using the Welfare Quality® Protocol. Ten FR and 11 IN farms in Brazil were assessed. Results are shown as either scores ranging...

Spain, M., Pearson, C., Rosenblatt, A. E. 2023. Social structure and habitat design affect the impact of a novel feeding enrichment for alligators. Zoo Biology 42(3), 383–389.

Providing enrichment that expands the range of behavioral opportunities associated with food acquisition and environmental exploration is an important contributing factor to the well-being of zoo animals. These behaviors can be difficult to promote in...

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...

Rana, M. S., Lee, C., Lea, J. M. et al. 2022. Commercial free-range laying hens’ preferences for shelters with different sunlight filtering percentages. Animals 12(3), 344.

Extreme sunlight might be aversive to free-range laying hens, discouraging them from going outside. Range enrichment with artificial shelters may protect hens from sunlight and increase range use. The preferences of 34–40-week-old Hy-Line Brown laying...

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...

Escobedo-Bonilla, C. M., Quiros-Rojas, N. M., Rudín-Salazar, E. 2022. Rehabilitation of marine turtles and welfare improvement by application of environmental enrichment strategies. Animals 12(3), 282.

Sea turtles perform various ecological services in several marine environments and are considered architects of the marine landscape. At present, they are endangered species due to anthropogenic threats, pollution and degradation of marine habitats. These...

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 =...

Leeds, A., Riley, A., Terry, M. et al. 2022. Out of sight, out of mind or just something in the way? Visual barriers do not reduce intraspecific agonism in an all-male group of Nile crocodiles (Crocodylus niloticus). Animals 12(3), 269.

Here, we evaluated if visual barriers could reduce intraspecific agonism in an all-male group of Nile crocodiles (Crocodylus niloticus) living in a zoo. Crocodiles were monitored for nearly 100 h, and four “hotspots” of aggression...

Rowe, E., Mullan, S. 2022. Advancing a “good life” for farm animals: Development of resource tier frameworks for on-farm assessment of positive welfare for beef cattle, broiler chicken and pigs. Animals 12(5), 565.

There is increasing recognition that farm animal welfare standards should ensure positive welfare, as well as prevent negative welfare. Resources that are valued by an animal and that provide opportunities to engage in motivated behaviours...

Mocz, F., Michel, V., Janvrot, M. et al. 2022. Positive effects of elevated platforms and straw bales on the welfare of fast-growing broiler chickens reared at two different stocking densities. Animals 12(5), 542.

In conventional rearing systems, fast-growing broiler chickens commonly experience welfare issues, such as contact dermatitis, walking difficulties or a lack of expression of species-specific behaviours. Enriching their environment may be a way to improve their...

Baker, P. E., Nicol, C. J., Weeks, C. A. 2022. The effect of hard pecking enrichment during rear on feather cover, feather pecking behaviour and beak length in beak-trimmed and intact-beak laying hen pullets. Animals 12(6), 674.

Injurious pecking, commonly controlled by beak trimming (BT), is a widespread issue in laying hens associated with thwarted foraging. This controlled study compared the effect in intact and beak-trimmed pullets of providing pecking pans to...

Sandilands, V., Baker, L., Donbavand, J. et al. 2022. Do hens use enrichments provided in free-range systems? Animals 12(8), 995.

Hens in free-range systems are given enrichments to increase foraging and limit injurious pecking, but the efficacy of enrichment types requires investigation. We studied hen behaviour and feather cover in eight commercial free-range flocks each...

Cargill, B. M., Benato, L., Rooney, N. J. 2022. A survey exploring the impact of housing and husbandry on pet snake welfare. Animal Welfare 31(2), 193-208.

Snake ownership is popular; however, housing and care may not always satisfy the animal's welfare needs. For example, snakes are often kept in environmental conditions that restrict their ability to stretch out fully or move...

Diggins, R., Burrie, R., Ariel, E. et al. 2022. A review of welfare indicators for sea turtles undergoing rehabilitation, with emphasis on environmental enrichment. Animal Welfare 31(2), 219-230.

For animals undergoing rehabilitation it is vital to monitor welfare in a way that is feasible, practical, and limits stress to the animal. The industry gold standard is to assess welfare under the Five Domains...

Vasdal, G., Gebhardt-Henrich, S.G., Kittelsen, K.E. et al. 2022. Commercial broiler breeder pullet hens use perches but show no preference for perch type or height. Applied Animal Behaviour Science 249, 105608.

An important behavioral need for laying hens is perching, but few studies have investigated perching behavior in commercial broiler breeder pullets. The aim of this study was to investigate perching behavior throughout the pullet period...