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. 
Nie, C., Ban, L., Ning, Z. et al. 2019. Feather colour affects the aggressive behaviour of chickens with the same genotype on the dominant white (I) locus. PLOS ONE 14(5), e0215921.

Aggression in chickens is a serious economic and animal welfare issue in poultry farming. Pigmentation traits have been documented to be associated with animal behaviour. Chicken pecking behaviour has been found to be related to...

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...

Sanchez-Casanova, R., Sarmiento-Franco, L., Segura-Correa, J. et al. 2019. Effects of outdoor access and indoor stocking density on behaviour and stress in broilers in the subhumid tropics. Animals 9(12), 1016.

Studies investigating the welfare of commercial-line broiler chickens raised in houses with outdoor access in the tropics are scarce, and none have investigated whether responses vary according to indoor conditions. Hence, we assessed the effects...

Hubert, S., Al-Ajeeli, M., Bailey, C. et al. 2019. The role of housing environment and dietary protein source on the gut microbiota of chicken. Animals 9(12), 1085.

The gut microbiota of chicken has received much attention due to its importance for bird health, food safety, and performance. In the United States, the impending transition to cage-free housing environments has raised many questions...

Zloch, A., Kuchling, S., Hess, M. et al. 2018. Influence of alternative husbandry systems on postmortem findings and prevalence of important bacteria and parasites in layers monitored from end of rearing until slaughter, Veterinary Record 182(12), 350.

In the present study 66 layer flocks housed in different alternative husbandry systems were monitored from placement of birds on the farm until slaughter to evaluate a possible influence on the occurrence of selected non-infectious...

Chen, S., Xiang, H., Zhu, X. et al. 2018. Free dietary choice and free-range rearing improve the product quality, gait score, and microbial richness of chickens. Animals 8(6), 84.

Poultry welfare has been extensively studied; however, there is a lack of rigorous scientific knowledge relating to the different aspects of welfare factors and how this may contribute to the production quantity and product quality...

Hunniford, M. E., Mason, G. J., Widowski, T. M. 2018. Laying hens’ preferences for nest surface type are affected by enclosure. Applied Animal Behaviour Science 201, 7-14.

The nest surfaces preferred by hens are inconsistent with those typically provided in commercial settings. However, little research has explored hens’ preferences for commercially available nest surfaces. Our objective was to compare hens’ preferences for...

Sirovnik, J., Stratmann, A., Gebhardt-Henrich, S. G. et al. 2018. Feeding from perches in an aviary system reduces aggression and mortality in laying hens. Applied Animal Behaviour Science 202, 53-62.

Some commercial aviary systems for laying hens allow birds to access feed by standing on perches instead of platforms. Despite reports that providing laying hens with perches relates to reduced aggression and cannibalism, and increased...

Sirovnik, J., Würbel, H., Toscano, M. J. 2018. Feeder space affects access to the feeder, aggression, and feed conversion in laying hens in an aviary system. Applied Animal Behaviour Science 198, 75-82.

In laying hens, minimal requirements for feeder space (cm per bird) are based primarily on data from small groups of hens (n

Jung, L., Knierim, U. 2018. Are practice recommendations for the prevention of feather pecking in laying hens in non-cage systems in line with the results of experimental and epidemiological studies? Applied Animal Behaviour Science 200, 1-12.

Feather pecking (FP) in laying hens is an important animal welfare problem in practice, despite extensive research and increasing sources of advice for farmers. We aimed to give an overview over results from experimental and...

Baxter, M., Bailie, C. L., O’Connell, N. E. 2018. Evaluation of a dustbathing substrate and straw bales as environmental enrichments in commercial broiler housing. Applied Animal Behaviour Science 200, 78-85.

The use of straw bales as an environmental enrichment is common for broiler chickens in enriched housing systems, however relatively little information exists about their effectiveness in improving welfare. There has also been no widespread...

James, C., Asher, L., Herborn, K. et al. 2018. The effect of supplementary ultraviolet wavelengths on broiler chicken welfare indicators. Applied Animal Behaviour Science 209, 55-64.

Qualities of the light environment are important for good welfare in a number of species. In chickens, UVA light is visible and may facilitate flock interactions. UVB wavelengths promote endogenous vitamin D synthesis, which could...

Egbuniwe, I. C., Ayo, J. O., Kawu, M. U. et al. 2018. Behavioral and hematological responses of broiler chickens administered with betaine and ascorbic acid during hot-dry season. Journal of Applied Animal Welfare Science, 21(4), 334-346.

Heat stress is a major problem in poultry production in tropical regions. Assessing the impact of thermally stressful environmental conditions on the welfare of broiler chickens is of great importance. Behavioral responses in a novel...

Bestman, M., Verwer, C., Brenninkmeyer, C. et al. 2017. Feather-pecking and injurious pecking in organic laying hens in 107 flocks from eight European countries. Animal Welfare 26(3), 355-363.

Feather-pecking and cannibalism may reduce the potential of organic husbandry to enhance the welfare of laying hens. We report risk factors for these issues based on a large survey of 107 commercial flocks in eight...

Nordquist, R., van der Staay, F., van Eerdenburg, F. et al. 2017. Mutilating procedures, management practices, and housing conditions that may affect the welfare of farm animals: Implications for welfare research. Animals 7(2), 12.

A number of mutilating procedures, such as dehorning in cattle and goats and beak trimming in laying hens, are common in farm animal husbandry systems in an attempt to prevent or solve problems, such as...

Carlson, A., Allen, C., Skoumbourdis, E. et al. 2017. Cooked food for non-human primates: A discussion by the Laboratory Animal Refinement & Enrichment Forum. Animal Technology and Welfare 16(2), 124-126.

"Do any of you give cooked food like pasta, potatoes or vegetables to non-human primates? What’s your experience? Do the animals benefit from cooked food; do they like it; does it affect their health in...

Vargas-Galicia, A. J., Sosa-Montes, E. Rodríguez-Ortega, L. T. et al. 2017. Effect of litter material and stocking density on bone and tendon strength, and productive performance in broilers. Canadian Journal of Animal Science 97(4), 673-682.

Litter material and stocking density were evaluated on welfare-related variables and productive performance in broilers. Male chicks (n = 744, “Ross 308” strain) were raised on either tezontle (TEZ) or wood shavings (WS) litter, with...

Brantsæter, M., Tahamtani, F. M., Nordgreen, J. et al. 2017. Access to litter during rearing and environmental enrichment during production reduce fearfulness in adult laying hens. Applied Animal Behaviour Science 189, 49-56.

Exaggerated fear-reactions are associated with injurious flying, smothering, feather pecking and other events that compromise animal welfare in laying hens. The aim of this study was to test the hypothesis that chicks with access to...

Girard, T. E, Zuidhof, M. J., Bench, C. J. 2017. Feeding, foraging, and feather pecking behaviours in precision-fed and skip-a-day-fed broiler breeder pullets. Applied Animal Behaviour Science 188, 42-49.

Broiler breeder chickens are feed-restricted to control growth and maximize chick production. Feed restriction creates welfare concerns as conventional skip-a-day feeding can increase activity levels and oral stereotypies during the rearing period. A precision feeding...

Archer, G. S., Mench, J. A. 2017. Exposing avian embryos to light affects post-hatch anti-predator fear responses. Applied Animal Behaviour Science 186, 80-84.

Environmental stimuli present during incubation can impact the behavior of birds post-hatch. To determine the effect of exposing broiler chicken embryos to light on fear-related behavior post-hatch, we conducted two experiments in which we incubated...

Wallace, P. Y., Asa, C. S., Agnew, M. et al. 2016. A review of population control methods in captive-housed primates. Animal Welfare 25(1), 7-20.

The success of breeding primates in captivity has led to a surplus number of animals in collections. This review examines published journals and key books to investigate the various methods of primate population control. Hormonal...

Rayner, A. C., Gill, R., Brass, D. et al. 2016. Smothering in UK free-range flocks. Part 2: investigating correlations between disease, housing and management practices. Veterinary Record 179(10), 252.

Smothering, when birds group together in a way that results in death from suffocation, is a welfare and economic concern for the egg industry. This questionnaire-based study explored correlations between disease, housing, management practices and...

Johannson, S. G., Raginski, C., Schwean-Lardner, K. et al. 2016. Providing laying hens in group-housed enriched cages with access to barley silage reduces aggressive and feather-pecking behaviour. Canadian Journal of Animal Science 96(2), 161-171.

Two trials were conducted to study the effect of feeding barley silage on the behaviour and performance of beak-trimmed laying hens. In each trial, 20 hens and 2 roosters were housed in each of eight...

Fuller, G., Raghanti, M. A., Dennis, P. M. et al. 2016. A comparison of nocturnal primate behavior in exhibits illuminated with red and blue light. Applied Animal Behaviour Science 184, 126-134.

Over evolutionary time, light from the sun, moon, and stars has provided organisms with reliable information about the passage of time; but modern artificial lighting has drastically altered these cues. Evidence is accumulating that exposure...

Stevens, T. 2016. Biscuit feeder increases foraging in baboons and reduces biscuit waste. Laboratory Animal Science Professional 4(3) (September), 54-55.

At the University of Oklahoma Health Sciences Center, Department of Comparative Medicine, we have a large captive colony of Olive Baboons (Papio anubis). Environmental enhancement is an integral part of the Comparative Medicine Baboon Research...