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. 
Inoue, N., Shimada, M. 2020. Comparisons of activity budgets, interactions, and social structures in captive and wild chimpanzees (Pan troglodytes). Animals 10(6), 1063.

Chimpanzees in zoos with sufficient and appropriate environmental enrichment devices are expected to exhibit behaviors, interactions, and societies similar to those in the wild. In this study, we compared the activity budgets of each observed...

Watson, H. A study into viable wooden enrichment objects for Syrian hamsters. Animal Technology and Welfare 19(1), 86-88.

Failing to provide hamsters with a method to wear down their teeth can lead to detrimental behaviour such as bar chewing, and health issues, for example, overgrown teeth and tooth loss. However, hamsters use their...

Bari, M. S., Downing, J. A., Dyall, T. R. et al. 2020. Relationships between rearing enrichments, range use, and an environmental stressor for free-range laying hen welfare. Frontiers in Veterinary Science 7, 480.

Enrichments during pullet rearing may improve adaptation and welfare of hens as they move from indoor rearing to a free-range system. Individual variation in outdoor ranging may also affect welfare. This study assessed the effects...

Reinhardt, V. (ed.) 2020. It’s Okay to Cry - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume V. Animal Welfare Institute, Washington, DC.

This is the 5th volume of selected discussions that took place on the electronic Laboratory Animal Refinement & Enrichment Forum between February 2016 and December 2019. The forum was created in October 2002; it allows...

Augustin, A. J., Crabbs, M. A., Sour, M. C. et al. 2020. Efficient, effective, reusable, and customizable social housing for chickens in the laboratory. Laboratory Animal Science Professional 8(5) (September/October), 56-58.

The Iowa State University Laboratory Animal Resources Department needed caging specifically designed and purposed to socially house chickens in the laboratory. As indoor housing requests for chickens increased, the need for a dedicated caging system...

Acharya, R., Rault, J.-L. 2020. Risk factors for feather-damaging behavior in companion parrots: A social media study. Journal of Veterinary Behavior 40, 43-49.

Studies on the etiology of behavioral problems often involve interference in the animal's routine or reliance on owners' self-reports like surveys. Gathering data from videos posted on social media, a technique coined ‘video mining’, offers...

Gomes Correa, M., Ferreira Rodrigues e Silva, C., Antunes Dias, L. et al. 2020. Welfare benefits after the implementation of slow-feeder hay bags for stabled horses. Journal of Veterinary Behavior 38, 61-66.

Horse confinement is a common practice worldwide. However, preventing horses from grazing and denying them social interaction can compromise their welfare and lead to undesirable consequences. Considering the hypothesis that increasing the forage consumption time...

Gebhardt-Henrich, S. G., Jordan, A., Toscano, M. J. et al. 2020. The effect of perches and aviary tiers on the mating behaviour of two hybrids of broiler breeders. Applied Animal Behaviour Science 233, 105145.

Broiler breeders are kept for the production of fertile eggs. They face serious welfare problems like aggressive behaviour of the males towards females during mating. Furthermore, broiler breeders are usually kept without perches which are...

Greene, L. K., Clarke, T. A., Southworth, C. A. et al. 2020. Daily lettuce supplements promote foraging behavior and modify the gut microbiota in captive frugivores. Zoo Biology 39(5), 334-344.

For captive primates, greater provisioning of leafy greens or foliage can promote natural foraging behavior while boosting fiber intake. Recalcitrant fiber, although minimally available to endogenous metabolism, is readily fermented into nutrients by gut microbes...

Liu, Z., Torrey, S., Newberry, R. C. et al. 2020. Play behaviour reduced by environmental enrichment in fast-growing broiler chickens. Applied Animal Behaviour Science 232, 105098.

The objective of this study was to evaluate effects of environmental enrichment on play behaviour in fast-growing broiler chickens. Chicks (19 of each sex) were randomly assigned to 6 non-enriched (NE) pens and 6 pens...

Ross, M., Rausch, Q., Vandenberg, B. et al. 2020. Hens with benefits: Can environmental enrichment make chickens more resilient to stress? Physiology Behavior, 226, 113077.

Resilience, the degree to which individuals are physiologically and behaviourally impacted by stressors, can be enhanced by positive experiences (e.g. positive moods in human, environmental enrichment in rodents). Such effects are important for human health...

Verspeek, J., Stevens, J. M. G. 2020. Food preference and nutrient composition in captive bonobos (Pan paniscus). Primates 61(5), 661-671.

Food preference has been studied in a range of Hominoidea in the wild and in captivity, allowing for interspecific comparisons. Chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla gorilla) prefer low-fibre, high-sugar foods, suggesting that frugivory...

Yamanashi, Y., Bando, H., Matsunaga, M. et al. 2020. Development of bed-building behaviors in captive chimpanzees (Pan troglodytes): Implication for critical period hypothesis and captive management. Primates 61(5), 639-646.

Wild great apes build beds for sleeping by combining tree branches or other vegetation, but the development of this behavior is poorly understood. We investigated the development of bed-building behaviors by conducting complementary cross-sectional and...

Bari, M. S., Downing, J. A., Dyall, T. R. et al. 2020. Relationships between rearing enrichments, range use, and an environmental stressor for free-range laying hen welfare. Frontiers in Veterinary Science 7, 480.

Enrichments during pullet rearing may improve adaptation and welfare of hens as they move from indoor rearing to a free-range system. Individual variation in outdoor ranging may also affect welfare. This study assessed the effects...

Campbell, D. L. M., Dyall, T. R., Downing, J. A. et al. 2020. Rearing enrichments affected ranging behavior in free-range laying hens. Frontiers in Veterinary Science 7, 446.

Within Australia, free-range systems are prevalent, but pullets destined for range access are reared indoors. This mismatch between rearing and layer housing may hinder adaptation to the free-range environment. Rearing enrichments could enhance pullet development...

Fanning, L., Larsen, H., Taylor, P. S. 2020. A preliminary study investigating the impact of musical concerts on the behavior of captive Fiordland penguins (Eudyptes pachyrhynchus) and collared peccaries (Pecari tajacu). Animals 10(11), 2035.

Captive animal welfare is important for establishments that exhibit species for education, conservation, and research. However, captive animals are often exposed to a number of potential stressors, such as visitors and anthropogenic noise. We aimed...

Mellor, E. L., Cuthill, I. C., Schwitzer, C. et al. 2020. Large lemurs: Ecological, demographic and environmental risk factors for weight gain in captivity. Animals 10(8), 1443.

Excessive body mass, i.e., being overweight or obese, is a health concern associated with issues such as reduced fertility and lifespan. Some lemur species are prone to extreme weight gain in captivity, yet others are...

Pullin, A. N., Temple, S. M., Bennett, D. C. et al. 2020. Pullet rearing affects collisions and perch use in enriched colony cage layer housing. Animals 10(8), 1269.

Hens reared in aviaries (AVI) as pullets have improved spatial abilities compared to hens reared in non-enriched cages (CON). However, this effect on behavior has been shown only to 23 weeks of age. Lohmann LSL-Lite...

Raspa, F., Tarantola, M., Bergero, D. et al. 2020. Time-budget of horses reared for meat production: Influence of stocking density on behavioural activities and subsequent welfare. Animals 10(8), 1334.

Horses reared for meat production can be kept in intensive breeding farms where they are housed in group pens at high stocking densities. The present study aimed to evaluate whether the expressed behaviours correlated with...

Rufener, C., Rentsch, A. K., Stratmann, A. et al. 2020. Perch positioning affects both laying hen locomotion and forces experienced at the keel. Animals 10(7), 1223.

The aim of this study was to assess the effect of perch positioning on laying hens’ locomotion and the resulting energy experienced at the keel. Twenty Nick Chick and 20 Brown Nick hens were trained...

Schreiter, R., Damme, K., Freick, M. 2020. Edible environmental enrichments in littered housing systems: Do their effects on integument condition differ between commercial laying hen strains? Animals 10(12), 2434.

The aim of this study was to investigate the effect of additional enrichment materials (EMs; pecking stones and alfalfa bales) on the occurrence of plumage damage, skin injuries, and toe injuries, with an emphasis on...

Coventry, C. 2020. Positive reinforcement training as physiotherapy for a brown capuchin (Sapajus apella). RATEL (Journal of the Association of British and Irish Wild Animal Keepers) 47(2), 16-17.

Physiotherapy can be used to treat an animal following surgery, to help correcting abnormal gait and for treating tendon, bone or ligament damage. […] Of course, an animal can’t just be given a set of...

Perea Garcia, J. O., Miani, A., Kristian Olsen Alstrup, A. et al. 2020. Orangulas: Effect of scheduled visual enrichment on behavioral and endocrine aspects of a captive orangutan (Pongo pygmaeus): Effect of scheduled visual enrichment on behavioral and endocrine aspects of a captive orangutan. Journal of Zoo and Aquarium Research, 8(1), 67-72.

Captivity may have adverse effects on captive great apes, who would spend much more of their time engaged in foraging and other activities in the wild. Enrichment interventions have the potential to alleviate the adverse...

Boesch, C. 2020. Mothers, environment, and ontogeny affect cognition. Animal Behavior and Cognition 7(3), 474–489.

The book “Folk Physics for Apes” remains a fascinating book about the way one captive peer-group of chimpanzees understand the world in which they grew. However, the very special living conditions these seven individuals faced...

Pedersen, I. J., Forkman, B. 2019. Improving leg health in broiler chickens: A systematic review of the effect of environmental enrichment. Animal Welfare 28(2), 215-230.

Leg problems are highly prevalent in modern broiler production and provision of environmental enrichment could be a strategy to improve leg health. Different types of environmental enrichment have undergone evaluation. Our objective was to conduct...