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. 
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...

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...

Parois, S. P., Van Der Zande, L. E., Knol, E. F. et al. 2022. A multi-suckling system combined with an enriched housing environment during the growing period promotes resilience to various challenges in pigs. Scientific Reports 12(1), 6804.

Little is known about the impact of social and environmental enrichment on improving livestock resilience, i.e. the ability to quickly recover from perturbations. We evaluated the effect of an alternative housing system (AHS) on resilience...

Archer, C., Garcia, A., Henderson, M. et al. 2022. Olfactory enrichment using a maternal pheromone improved post-weaning pig performance and behavior. Frontiers in Veterinary Science 9, 965370.

The post-weaning environment in commercial pig nursery buildings is typically devoid of both the sow and her semiochemicals. Among other factors, the loss of maternal odors may contribute to post-weaning stress. In this work, we...

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...

de Castro Lippi, I. C., Caldara, F. R., de Lima Almeida Paz, I. C. et al. 2022. Global and Brazilian scenario of guidelines and legislation on welfare in pig farming. Animals 12(19), 2615.

The evolution of scientific knowledge regarding animal sentience, together with the growing concerns of consumers regarding current production models, has brought with it the responsibility of reviewing many practices carried out in industrial swine farming...

Parois, S. P., Van Der Zande, L. E., Knol, E. F. et al. 2022. A multi-suckling system combined with an enriched housing environment during the growing period promotes resilience to various challenges in pigs. Scientific Reports 12(1), 6804.

Little is known about the impact of social and environmental enrichment on improving livestock resilience, i.e. the ability to quickly recover from perturbations. We evaluated the effect of an alternative housing system (AHS) on resilience...

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...

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...

Luna, D., González, C., Byrd, C. J. et al. 2021. Do domestic pigs acquire a positive perception of humans through observational social learning? Animals 11(1), 127.

Farm animals can perceive humans positively by observing another animal being positively handled. This study evaluated whether pigs acquire a positive perception of humans after observing either a high or low socially ranked conspecific receiving...

Hayes, M. E., Hemsworth, L. M., Morrison, R. S. et al. 2021. Effects of positive human contact during gestation on the behaviour, physiology and reproductive performance of sows. Animals 11(1), 214.

Previous positive interactions with humans may ameliorate the stress response of farm animals to aversive routine practices such as painful or stressful procedures, particularly those associated with stockpeople. We studied the effects of positive handling...

Wallgren, T., Gunnarsson, S. 2021. Effect of straw provision in racks on tail lesions, straw availability, and pen hygiene in finishing pigs. Animals 11(2), 379.

Unfulfilled exploratory behavior in pigs has been linked to tail biting, which causes reduced performance and welfare. Provision of straw can reduce tail biting, but large straw rations can cause poor hygiene in pens. This...

Pol, F., Huneau-Salaün, A., Gallien, S. et al. 2021. Compressed brown algae as a potential environmental enrichment material in growing pigs. Animals 11(2), 315.

In barren housing conditions, enrichment materials are given to pigs to improve their welfare. Here, we assessed the suitability of an algae-based cylinder as an enrichment material on the behavioral, physiological, health and productivity welfare...

Hirskyj-Douglas, I., Kankaanpää, V. 2021. Exploring how white-faced sakis control digital visual enrichment systems. Animals 11(2), 557.

Computer-enabled screen systems containing visual elements have long been employed with captive primates for assessing preference, reactions and for husbandry reasons. These screen systems typically play visual enrichment to primates without them choosing to trigger...

Lambert, K. 2021. DIY: Ice cream cone spiced foraging cups. Laboratory Animal Science Professional 9(1) (January/February), 36.

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

Lambert, K. 2021. DIY: Ice produce blocks. Laboratory Animal Science Professional 9(2) (March/April), 41.

This great cool-down snack is ideal for group or singly housed swine or nonhuman primates (particularly in larger pen-style housing). This item can be customized for canines as well by modifying the liquid used and/or...

Williams, W. R. 2021. Edible nail polish as a novel enrichment strategy for single-housed nonhuman primates. Laboratory Animal Science Professional 9(2) (March/April), 50-51.

At the University of Oklahoma Health Sciences Center, NHPs may need to be singly housed for research purposes or veterinary care, and it can be challenging to keep them optimally enriched. This sometimes results in...

Funkhouser, J. A., Mayhew, J. A., Mulcahy, J. et al. 2021. Human caregivers are integrated social partners for captive chimpanzees. Primates 62(2), 297–309.

In a captive environment, it is challenging to ensure the highest level of social and psychological well-being for species with naturally complex social organizations and structures. There is a growing need to meet the social...

Ly, L. H., & Weary, D. M. 2021. Facial expression in humans as a measure of empathy towards farm animals in pain. PLOS ONE 16(3), e0247808.

People often express concern for the welfare of farm animals, but research on this topic has relied upon self-report. Facial expressions provide a quantifiable measure of emotional response that may be less susceptible to social...

Swan, K.-M., Telkänranta, H., Munsterhjelm, C. et al. 2021. Access to chewable materials during lactation affects sow behaviour and interaction with piglets. Applied Animal Behaviour Science 234, 105174.

We investigated how providing chewable materials to piglets during the early weeks of life affect sow behaviour, sow and piglet interaction and sow health in pens with farrowing crates. We divided 59 pregnant sows into...