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. 
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...

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 =...

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...

Vonk, J., Truax, J., McGuire, M. C. 2022. A food for all seasons: Stability of food preferences in gorillas across testing methods and seasons. Animals 12(6), 685.

Decisions about which foods to use during training and enrichment for captive animals may be based on invalid assumptions about individuals’ preferences. It is important to assess the stability of food preferences given that one-time...

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...

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...

Medina, A. 2022. Creative enrichment for nonhuman primates. Laboratory Animal Science Professional 10(1) (January/February), 42-43.

Providing novel and creative enrichments for nonhuman primates improves their mental wellbeing and is thus an important aspect of all husbandry programs. These enrichments are often presented through variations in diet, toys, and environmental features...

Buchanan, K. 2022. DIY: Ants on a log. Laboratory Animal Science Professional 10(1) (January/February), 44.

This traditional snack has a variety of options for NHP enrichment. From fruit to cereals, get creative with the “ants” and remember to consider different fillings for the celery log.

Birolo, M., Trocino, A., Zuffellato, A. et al. 2022. Use of gnawing hay blocks: Effects on productive performance, behavior and reactivity of growing rabbits kept in parks with different sex-group compositions. Animals 12(9), 1212.

To improve animal welfare in collective park housing systems, this study assessed the effects of the provision of gnawing hay blocks and the group composition (F: females, M: males, FM: mixed sex) on performance, behavior...

Son, J., Lee, W.-D., Kim, H.-J. et al. 2022. Effect of providing environmental enrichment into aviary house on the welfare of laying hens. Animals 12(9), 1165.

This study aimed to determine the effects of providing environmental enrichment materials—pumice stone and alfalfa hay—to laying hens in the aviary system. A total of 2196 40-week-old Hy-Line Brown laying hens were randomly allotted to...

Dancer, A. M. M., Díez-León, M., Bizley, J. K. et al. 2022. Housing and environmental enrichment of the domestic ferret: A multi-sector survey. Animals 12(9), 1065.

Ferrets (Mustela putorius furo) are kept and used in multiple sectors of society, but little is known about how they are housed and what environmental enrichment (EE) they may benefit from. We aimed to help...

Greeson, J. L., Gabriel, K. I., Mulcahy, J. B. et al. 2022. An evaluation of ethograms measuring distinct features of enrichment use by captive chimpanzees (Pan troglodytes). Animals 12(16), 2029.

Environmental enrichment provides mental stimulation and minimizes abnormal behaviors in captive animals. In captive chimpanzees, individual animals may vary in the ways in which they benefit from enrichment or use enrichment devices, so investigating nuances...

Vasdal, G., Gebhardt-Henrich, S. G., Tahamtani, F. et al. 2022. Perch use in commercial broiler breeders – Preference for perch material and effect of age. Applied Animal Behaviour Science 253, 105680.

Unlike for laying hens in most European countries, few broiler breeders have access to perches, and there is a need for more knowledge on perching behavior in broiler breeders. The aim of this study was...

Spitzer, H. B., Meagher, R. K., Proudfoot, K. L. 2022. The impact of providing hiding spaces to farmed animals: A scoping review. PLOS ONE 17(11), e0277665.

Many wild animals perform hiding behaviours for a variety of reasons, such as evading predators or other conspecifics. Unlike their wild counterparts, farmed animals often live in relatively barren environments without the opportunity to hide...

Padrell, M., Amici, F., Córdoba, M. P. et al. 2022. Cognitive enrichment in a social setting: Assessing the use of a novel food maze in sanctuary-housed chimpanzees. Primates 63(5), 509–524.

Foraging devices are effective enrichment tools for non-human primates, as they provide both cognitive and manipulative stimulation that may enhance these animals’ welfare. We assessed the behavioral effects of a novel tool-based enrichment on 14...

Butler, S. 2022. Gardening for Gorillas. Orla Kelly Publishing, Dublin, Ireland. 369 p.

During the author's 37 years as Curator of Horticulture, Dublin Zoo transformed from an almost Victorian appearance to a verdant green ark. A progressive masterplan focused on animal welfare and themed habitats reflects the spirit...

Caselli, M., Messeri, P., Dessì-Fulgheri, F. et al. 2022. Enriching zoo-housed ring-tailed lemurs (Lemur catta): Assessing the influence of three types of environmental enrichment on behavior. Animals 12(20), 2836.

Environmental enrichment is a management tool used to promote positive animal welfare by stimulating species-specific behaviors and providing animals with opportunities to exert choice and control over the environment. Our study aimed to evaluate the...

Nagabaskaran, G., Skinner, M., Miller, N. 2022. Western hognose snakes (Heterodon nasicus) prefer environmental enrichment. Animals 12(23), 3347.

The environmental enrichment needs of snakes are often disregarded. Using preference testing, we aimed to shed light on the enrichment preferences of a popular pet species, the western hognose snake (Heterodon nasicus). Snakes’ enclosures were...

Schwarzer, A., Erhard, M., Schmidt, P. et al. 2022. Effects of stocking rate and environmental enrichment on the ontogeny of pecking behavior of laying hen pullets confined in aviary compartments during the first 4 weeks of life. Animals 12(19), 2639.

The objective of this study was to describe the ontogeny of the severe feather pecking (SFP), gentle feather pecking (GFP), aggressive pecking (AP), and enrichment pecking (EP) of non-beak-trimmed Lohmann Brown (LB)-pullets during the first...

Xu, D., Shu, G., Liu, Y. et al. 2022. Farm animal enrichments improve the welfare of layer chicks and pullets: A comprehensive review. Animals 12(19), 2610.

Currently, cage housing is regarded as a global mainstream production system for laying hens. However, limited living space and confinement of birds in cages cause welfare and health problems, such as feather pecking, osteoporosis, obesity...

Yamanashi, Y., Hitoosa, K., Yoshida, N. et al. 2022. Do chimpanzees enjoy a virtual forest? A pilot investigation of the use of interactive art as a form of environmental enrichment for zoo-housed chimpanzees. American Journal of Primatology 84(10), e23343.

Environmental enrichment is essential for the well-being of zoo animals. Recent advances in sensor and video technologies may contribute to improvements in enrichment in terms of their flexibilities and time constraints. The purpose of this...