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. 
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...

Svartberg, K. 2022. A possible basis for personality in dogs: Individual differences in affective predispositions. Applied Animal Behaviour Science 255, 105740.

Previously, dog personality traits that seem to correspond have been identified by the Dog Mentality Assessment (DMA) and the Behaviour and Personality Assessment in Dogs (BPH): Playfulness, Sociability, Curiosity/fearlessness (DMA) vs. Non-social fearfulness (BPH), Aggressiveness...

Aldhshan, M. S., Mizuno, T. M. 2022. Effect of environmental enrichment on aggression and the expression of brain-derived neurotrophic factor transcript variants in group-housed male mice. Behavioural Brain Research 433, 113986.

Social and environmental factors influence behavior via modulation of brain physiological functions. Environmental enrichment (EE) is an animal housing technique that provides complex sensory, motor, and social stimulation, leading to modifications in the innate aggressiveness...

Mieske, P., Hobbiesiefken, U., Fischer-Tenhagen, C. et al. 2022. Bored at home?—A systematic review on the effect of environmental enrichment on the welfare of laboratory rats and mice. Frontiers in Veterinary Science 9, 899219.

Boredom is an emotional state that occurs when an individual has nothing to do, is not interested in the surrounding, and feels dreary and in a monotony. While this condition is usually defined for humans...

Sanders, K., Fernandez, E. J. 2022. Behavioral implications of enrichment for golden lion tamarins: A tool for ex situ conservation. Journal of Applied Animal Welfare Science 25(3), 214-223.

The re-release of golden lion tamarins (Leontopithecus rosalia), from zoos into the wild, is considered to be an ex situ conservation success story. However, zoo-born golden lion tamarins have lower survival rates than their wild-born...

de França Santos, M., de Menezes Galvão, A. C., Santos Silva, F. et al. 2022. Welfare improvement by enrichment programs in common marmoset females under social isolation. Journal of Applied Animal Welfare Science 25(3), 297-309.

Animal welfare is critical to buffer stress in captive animals and to ensure the reliability of data from studies. The most usual environmental enrichment technique (EE) for social non-human primates is the social enrichment. However...

Alaniz, A. J., Astudillo-Hinojosa, K., Soto, A. F. et al. 2022. Rapid behavioral recovery based on environmental enrichment of a white-throated toucan (Ramphastos tucanus: Ramphastidae) affected by collision trauma. Journal of Veterinary Behavior 57, 1-5.

Captive animals that have experienced traumatic events require a high range of care prior to reintroducing them into their natural habitat; and this care should ensure their welfare in captivity. This report shows the ethological...

Hurley, A., Cotton, A. 2022. Foraging enrichment affects behaviour and enclosure utilisation in captive male gelada Theropithecus gelada. Journal of Zoo and Aquarium Research 10(3), 129-138.

Enrichment devices are important tools to engage zoo-housed animals in species-specific natural behaviours, which is critical to ensure animal welfare. The gelada Theropithecus gelada has a unique graminivorous feeding ecology, yet there is minimal enrichment...

Neto, T., Faustino-Rocha, A. I., Gil da Costa, R. M. et al. 2022. A quick and low-intensity method for oral administration to large numbers of mice: A possible alternative to oral gavage. Laboratory Animals 56(2), 185-190.

Oral administration of medication to experimental animals is a cause of significant stress. When coupled to animals who are already under strenuous circumstances due to the disease being modelled, there is a significant risk for...

Ramírez-Rodríguez, G. B., Gutiérrez-Vera, B., Ortiz-López, L. et al. 2022. Environmental enrichment: Dissociated effects between physical activity and changing environmental complexity on anxiety and neurogenesis in adult male Balb/C mice. Physiology & Behavior 254, 113878.

Several factors, including environmental modifications, stimulate neuroplasticity. One type of neuroplasticity consists in the generation of new neurons in the dentate gyrus of the hippocampus. Neurogenesis is modulated by environmental enrichment (ENR, tunnels plus running...

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...

Fink, L. B., Mukobi, A., Gruber, L. et al. 2022. Longitudinal analysis of variability in fecal glucocorticoid metabolite concentrations in three orangutans (Pongo pygmaeus pygmaeus and Pongo pygmaeus abelii) before, during, and after transition from a regular habitat environment to temporary housing in indoor holding facilities. Animals 12(23), 3303.

Considerable research has been conducted on the effects of inter-institutional transfers, but far less consideration has been given to intra-institutional transfers and extended housing in off-habitat holding. On 15 May 2018, The Oregon Zoo’s orangutans...

Mieske, P., Hobbiesiefken, U., Fischer-Tenhagen, C. et al. 2022. Bored at home?—A systematic review on the effect of environmental enrichment on the welfare of laboratory rats and mice. Frontiers in Veterinary Science 9, 899219.

Boredom is an emotional state that occurs when an individual has nothing to do, is not interested in the surrounding, and feels dreary and in a monotony. While this condition is usually defined for humans...

Ruge, L., Mancini, C. 2022. An ethics toolkit to support animal-centered research and design. Frontiers in Veterinary Science 9, 891493.

Designers and researchers who work with animals need to employ an array of ethical competencies to guarantee the welfare of animals taking part in animal-centered research. The emerging field of Animal-Computer Interaction (ACI), which deals...

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...

Weir, R. 2022. The effects of various enrichment methods on the engagement nd inter-group behaviour of captive chacma baboons. Canopy 23(1), 4–6.

The goal of this study was to answer two research questions: (1) how important is it to rotate enrichment types to maintain high levels of engagement in individually-housed adult chacma baboons? and (2) which methods...

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...

Cait, J., Cait, A., Scott, R. W. et al. 2022. Conventional laboratory housing increases morbidity and mortality in research rodents: Results of a meta-analysis. BMC Biology 20(1), 15.

Over 120 million mice and rats are used annually in research, conventionally housed in shoebox-sized cages that restrict natural behaviours (e.g. nesting and burrowing). This can reduce physical fitness, impair thermoregulation and reduce welfare (e.g...

Riedel, A., Rieke, L., Kemper, N. et al. 2022. A place to be? Use of winter gardens with and without automatic enrichment devices by laying hens. Applied Sciences 12(7), 3650.

Since the abolition of beak trimming in laying hens in Germany, the importance of adequate enrichment material to help reduce feather pecking and cannibalism has grown. Here we tested an automatic enrichment device dosing grain...

Tuozzi, A., Arhant, C., Anderle, K. et al. 2021. Effects of human presence and voice on the behaviour of shelter dogs and cats: A preliminary study. Animals 11(2), 406.

Reading books to shelter animals combining auditory enrichment with human presence is increasingly used although its effects on animal welfare have not yet been investigated. This study compared the behaviour of single-housed shelter dogs and...