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. 
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...

Evison, E., McKenzie, A., Holmes, L. 2020. Social and environmental impacts on sleep in captive Asian elephants (Elephas maximus). Zoo Biology 39(6), 397-404.

Modern zoos strive to improve standards of animal management, husbandry and welfare of their animals as part of a continual evaluation process. Elephants (Elephantidae) have received particular attention in recent years due to the challenge...

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...

Moroki, Y. 2020. Impact of flooring type on the sham dustbathing behaviour of caged laying hens. Applied Animal Behaviour Science 230, 105066.

Feed particles are preferred for foraging and they are also a stimulus for sham dustbathing. Most sham dustbathing bouts start with bill raking in the feed by caged hens. As hens often exhibit a floor...

Jung, L., Brenninkmeyer, C., Niebuhr, K. et al. 2020. Husbandry conditions and welfare outcomes in organic egg production in eight European countries. Animals 10(11), 2102.

In the European research project HealthyHens, welfare indicators as well as husbandry and management conditions were recorded in 107 organic laying hen farms in eight countries. Farms were visited at peak and end of lay...

Monckton, V., Ellis, J. L., Harlander-Matauschek, A. 2020. Floor substrate preferences of chickens: A meta-analysis. Frontiers in Veterinary Science 7, 584162.

Environmental enrichment promotes sensory and motor stimulation for species-typical behaviors, which in turn enhance animal well-being. For farmed Galliformes, housing systems often limit enrichment to bedding and litter, that simultaneously act as material for dustbathing...

Veasey, J. S. 2020. Can zoos ever be big enough for large wild animals? A review using an expert panel assessment of the psychological priorities of the Amur tiger (Panthera tigris altaica) as a model species. Animals 10(9), 1536.

The ecology of large, wide-ranging carnivores appears to make them vulnerable to conservation challenges in the wild and welfare challenges in captivity. This poses an ethical dilemma for the zoo community and supports the case...

Sokołowicz, Z., Dykiel, M., Topczewska, J. et al. 2020. The effect of the type of non-caged housing system, genotype and age on the behaviour of laying hens. Animals 10(12), 2450.

This study investigated the welfare of laying hens in different non-caged housing systems, namely a deep-litter barn system (BS), a free-range system (FRS) and an organic system (OS). The study was conducted on 270 hens...

Goodroe, A., Fitz, C., Bakker, J. 2020. Current topics in marmoset anesthesia and analgesia. ILAR Journal 61(2-3), 218-229.

Anesthetic and analgesics are essential components of both clinical and research procedures completed in marmosets. A review of current anesthetic and analgesic regimens for marmosets has been complied to provide a concise reference for veterinarians...

Blanchett, M., Finegan, E., Atkinson, J. 2020. The effects of increasing visitor and noise levels on birds within a free-flight aviary examined through enclosure use and behavior. Animal Behavior and Cognition 7(1), 49–69.

Visitors in a zoo environment have the potential to impact the animals that they are viewing in a variety of ways. Recently, there have been suggestions that free-range enclosures, where visitors can walk directly through...

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...

Moroki, Y. 2019. Sham dustbathing in cages by subordinate hens is increased by a partition providing isolation. Applied Animal Behaviour Science 210, 68-72.

Subordinate hens express less sham dustbathing in cages than higher ranked hens, their bouts often being disturbed by a higher ranked hen. However, seeing conspecifics seems to encourage this behaviour by hens. So to avoid...

Harris, K., New, R., Smith, P. et al. 2019. Refinement: promoting Gallus Gallus welfare in an experimental poultry unit. Animal Technology and Welfare 18(2), 137-139. (IAT Congress 2018 Poster Presentation)

The poultry team at The Pirbright Institute reviewed existing husbandry practices and trialled several refinement practices. The objective was to provide the birds used in research with an environment which enables them to express their...

Kroeker, R., Chichester, L., Lee, G. H. et al. 2019. Effects of pregnancy, outdoor access, and antifungal medication on hair loss in breeding-age female pigtailed macaques (Macaca nemestrina). Comparative Medicine 69(3), 221–227.

Over 18 mo, adult female pigtailed macaques (Macaca nemestrina) housed at a breeding facility in Arizona were monitored every 6 mo for alopecia. The study period coincided with the movement of a majority of animals...

Engel, R. M., Thomas III, M. L., Banks, R. E. 2019. Regional anesthesia for dentistry and orofacial surgery in rhesus macaques (Macaca mulatta). JAALAS 58(2), 223-230.

Regional anesthesia is a commonly used adjunct to orofacial dental and surgical procedures in companion animals and humans. However, appropriate techniques for anesthetizing branches of the mandibular and maxillary nerves have not been described for...

Bloomsmith, M. A., Clay, A. W., Lambeth, S. P. et al. 2019. Survey of behavioral indices of welfare in research chimpanzees (Pan troglodytes) in the United States. JAALAS 58(2), 160-177.

Chimpanzees demand specialized housing and care and the highest degree of attention to animal welfare. The current project used a survey method to collate information on chimpanzee housing and behavioral indices of welfare across all...

Association of Primate Veterinarians. 2019. Association of Primate Veterinarians’ Position Statement: Cerebrospinal fluid aspiration for nonhuman primates in biomedical research. JAALAS 58(4), 428-429.

The Association of Primate Veterinarians (APV) recognizes that CSF collection may be required for both clinical and research purposes in nonhuman primates (NHP). Because there are inherent risks associated with the technique, the laboratory animal...

National Academies of Sciences, Engineering, and Medicine. 2019. Care, Use, and Welfare of Marmosets as Animal Models for Gene Editing-Based Biomedical Research: Proceedings of a Workshop. The National Academies Press: Washington, DC, 122 pp.

The marmoset, a type of small monkey native to South America, is a research model of increasing importance for biomedical research in the United States and globally. Marmosets offer a range of advantages as animal...

Ali, A. B. A., Campbell, D. L. M., Karcher, D. M. et al. 2019. Daytime occupancy of resources and flooring types by 4 laying hen strains in a commercial-style aviary. Journal of Veterinary Behavior 31, 59-66.

In response to consumer demands and legislative measures for improving hens' welfare, many laying hen producers are replacing conventional cages with aviaries. Aviary resources, such as nest boxes, litter areas, ledges, and perches, are intended...

Edwards, K. L., Miller, M. A., Carlstead, K. et al. 2019. Relationships between housing and management factors and clinical health events in elephants in North American zoos. PLOS ONE 14(6), e0217774.

Elephants experience a number of health issues that can contribute to their well-being and survival. In managed populations, housing conditions and management practices can influence individual health, so potential risk factors associated with morbidity or...

Brown, J. L., Carlstead, K., Bray, J. D. et al. 2019. Individual and environmental risk factors associated with fecal glucocorticoid metabolite concentrations in zoo-housed Asian and African elephants. PLOS ONE 14(9), e0217326.

A recent large-scale welfare study in North America involving 106 Asian (Elephas maximus) and 131 African (Loxodonta africana) elephants at 64 accredited facilities identified links (i.e., risk factors) between zoo environmental factors and a number...

Ishizuka, S., Kawamoto, Y., Toda, K. et al. 2019. Bonobos’ saliva remaining on the pith of terrestrial herbaceous vegetation can serve as non-invasive wild genetic resources. Primates 60(1), 7–13.

Evaluating the genetic diversity of natural populations of endangered species is important for conservation. Although the genetic analysis of wildlife usually requires collecting DNA non-invasively, the variety of non-invasive DNA sampling methods is limited for...

Anderson, J. R., Ang, M. Y. L., Lock, L. C. et al. 2019. Nesting, sleeping, and nighttime behaviors in wild and captive great apes. Primates 60(4), 321–332.

The past few decades have seen a burgeoning of scientific studies on great apes’ use of nests for sleeping in the wild, as well as their nesting behavior and sleep in captivity. We review recent...

Scott, N. L., LaDue, C. A. 2019. The behavioral effects of exhibit size versus complexity in African elephants: A potential solution for smaller spaces. Zoo Biology 38(5), 448-457.

Population-level analyses suggest that habitat complexity, but not necessarily space availability, has important welfare outcomes for elephants in human care. At the Dallas Zoo, the opening of a new exhibit complex allowed us to measure...

Cox, R. J., Nol, P., Ellis, C. K. et al. 2019. Research with agricultural animals and wildlife. ILAR Journal 60(1), 66-73.

In fiscal year 2016, agricultural animals such as swine, sheep, goats, and cattle represented 10% of the 820 812 animals used in USDA-regulated research. In addition to traditional agricultural animals, research studies using captive wildlife...