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. 
Lambert, H., Cornish, A., Waley, D. 2024. The value of regulating stocking densities in aquaculture must not be dismissed: A reply to Saraiva et al. 2022. Frontiers in Veterinary Science 10.

We would like to rebut the argument made by Saraiva et al. (1) in their paper “Finding the “golden stocking density”: a balance between fish welfare and farmers' perspectives,” that stocking densities should not be...

Robinson, L. M., Weiss, A. (Eds.) 2023. Nonhuman Primate Welfare: From History, Science, and Ethics to Practice. Springer, Cham, Switzerland. 671 p.

This volume reviews the broad topic of welfare in nonhuman primates under human care. Chapters detail the history of primates in captivity, ethical and legal issues surrounding the use of nonhuman primates as entertainment or...

Ausderau, K. K., Colman, R. J., Kabakov, S. et al. 2023. Evaluating depression- and anxiety-like behaviors in non-human primates. Frontiers in Behavioral Neuroscience 16, 1006065.

Depression and anxiety are some of the most prevalent and debilitating mental health conditions in humans. They can present on their own or as co-morbidities with other disorders. Like humans, non-human primates (NHPs) can develop...

Evans, L., Brooks, G. C., Anderson, M. G. et al. 2023. Environmental complexity and reduced stocking density promote positive behavioral outcomes in broiler chickens. Animals 13(13), 2074.

The objective was to evaluate the impacts of a complex environment and stocking density on Ross 708 broiler chicken behaviors. Eight pens contained either high complexity (HC) or low complexity (LC) environments, and high (HD)...

Vicentini, R. R., El Faro, L., Ujita, A. et al. 2023. Effects of training for first milking involving positive tactile stimulation on post-calving maternal behaviors in primiparous gyr dairy cows. Animals 13(5), 921.

In dairy systems with Zebu breeds, calves are not immediately separated from their dams after calving; consequently, maternal care and protective behavior are important, influencing both productive performance and stockpeople’s safety. Our objectives were to...

Alejandro, J., Yamanashi, Y., Nemoto, K. et al. 2023. Reducing stress and stereotypic behaviors in captive female pygmy slow lorises (Nycticebus pygmeaus). American Journal of Primatology 85(7), e23495.

Improving captive conditions of pygmy slow lorises (Nekaris and Nijman have recently suggested that the pygmy slow loris should be called the pygmy loris and is distinctive enough to warrant a new genus, Xanthonycticebu) (Nycticebus...

Brando, S., Norman, M. 2023. Handling and training of wild animals: Evidence and ethics-based approaches and best practices in the modern zoo. Animals 13(14), 2247.

There is an ethical responsibility to provide all animals living in human care with optimal and positive well-being. As animals living in zoos and aquariums frequently interact with their human caregivers as part of their...

Mählis, G., Kleine, A., Lüschow, D. et al. 2023. Clicker training as an applied refinement measure in chickens. Animals 13(24), 3836.

When using chickens in animal studies, the handling of these animals for sample collection or general examinations is considered stressful due to their prey nature. For the study presented here, plasma and salivary corticosterone as...

Molinaro, H. G., Anderson, G. S., Gruny, L. et al. 2022. Use of blood lactate in assessment of manual capture techniques of zoo-housed crocodilians. Animals 12(3), 397.

Species-specific welfare indicators are important in promoting positive welfare for zoo animals. Reptiles are a notoriously understudied group in regards to behavior, welfare needs, and husbandry requirements. Using opportunistically obtained samples, we evaluated how blood...

Nekaris, K. A.-I., Campera, M., Chimienti, M. et al. 2022. Training in the dark: Using target training for non-invasive application and validation of accelerometer devices for an endangered primate (Nycticebus bengalensis). Animals 12(4), 411.

Accelerometers offer unique opportunities to study the behaviour of cryptic animals but require validation to show their accuracy in identifying behaviours. This validation is often undertaken in captivity before use in the wild. While zoos...

Mocz, F., Michel, V., Janvrot, M. et al. 2022. Positive effects of elevated platforms and straw bales on the welfare of fast-growing broiler chickens reared at two different stocking densities. Animals 12(5), 542.

In conventional rearing systems, fast-growing broiler chickens commonly experience welfare issues, such as contact dermatitis, walking difficulties or a lack of expression of species-specific behaviours. Enriching their environment may be a way to improve their...

Lutz, C. K., Coleman, K., Hopper, L.M. et al. 2022. Nonhuman primate abnormal behavior: Etiology, assessment, and treatment. American Journal of Primatology 84(6), e23380.

Across captive settings, nonhuman primates may develop an array of abnormal behaviors including stereotypic and self-injurious behavior. Abnormal behavior can indicate a state of poor welfare, since it is often associated with a suboptimal environment...

Williams, M. L., Torrini, L. A., Nolan, E. J. et al. 2022. Using classical and operant conditioning to train a shifting behavior in juvenile false water cobras (Hydrodynastes gigas). Animals 12(10), 1229.

All animals have the capacity to learn through operant conditioning and other types of learning, and as a result, zoos and other animal care facilities have shifted towards the use of positive reinforcement training to...

Thompson, J. S., Hudson, C. D., Huxley, J. N. et al. 2022. A randomised controlled trial to evaluate the impact of indoor living space on dairy cow production, reproduction and behaviour. Scientific Reports 12(1), 3849.

As a global society, we have a duty to provide suitable care and conditions for farmed livestock to protect animal welfare and ensure the sustainability of our food supply. The suitability and biological impacts of...

Saraiva, J. L., Rachinas-Lopes, P., Arechavala-Lopez, P. 2022. Finding the “golden stocking density”: A balance between fish welfare and farmers’ perspectives. Frontiers in Veterinary Science 9, 930221.

The effects of stocking density on fish welfare are complex and involve many interacting parameters. This complex relationship between fish welfare, stocking density and influencing factors make it challenging to define a specific optimal (“golden”)...

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...

van der Eijk, J. A. J., Gunnink, H., Melis, M. et al. 2022. Reducing stocking density benefits behaviour of fast- and slower-growing broilers. Applied Animal Behaviour Science 257, 105754.

The broiler industry has come under sustained pressure from welfare organizations to improve broiler welfare. Breed and stocking density are important factors for broiler welfare and are often specified as criteria for higher welfare systems...

Anderson, M. G., Campbell, A. M., Kuhn, D. D. et al. 2022. Impact of environmental complexity and stocking density on affective states of rainbow trout (Oncorhynchus mykiss). Animal Cognition 25(5), 1331–1343.

Environmental condition, such as environmental complexity or stocking density, can directly or indirectly influence animal emotion and ultimately, affective state. Affective states of animals can be assessed through judgement bias tests, evaluating responses to ambiguous...

Schwarzer, A., Rauch, E., Bergmann, S. et al. 2022. Risk factors for the occurrence of feather pecking in non-beak-trimmed pullets and laying hens on commercial farms. Applied Sciences 12(19), 9699.

Severe feather pecking (SFP) is a behavioral disorder, for which there are multifactorial reasons. Various aspects of pullet and laying-hen husbandry—including housing conditions, management, feeding, and genetics—must be considered, to prevent negative outcomes, such as...

Petek, M.,Çavuşoğlu, E. 2021. Welfare assessment of two free-range laying hen flocks in Turkey. Journal of Applied Animal Welfare Science 24(1), 56-63.

This study aimed to determine the prevalence of keel bone deviations and feather damage of laying hens in two different free-range housing systems under commercial conditions. Both of the free-range systems had an indoor barn...

Sørensen, D., Cloutier, S., Gaskill, B. (Eds.). 2021. Animal-centric Care and Management - Enhancing Refinement in Biomedical Research. CRC Press, Boca Raton, FL.

The concept of the 3Rs (Refinement, Reduction and Replacement) has been used as a framework for improving the welfare of laboratory animals for the last half century. By establishing an animal-centric view on housing and...

Phillips, H. N., Heins, B. J. 2021. Effects of outdoor stocking density on growth, feather damage and behavior of slow-growing free-range broilers. Animals 11(3), 688.

Access to pasture is a main benefit of free-range broiler housing systems, yet the level of outdoor stocking density on broiler animal welfare remains unsettled. The growth, feather damage, pasture ranging and behaviors were assessed...

Anderson, M. G., Campbell, A. M., Crump, A. et al. 2021. Effect of environmental complexity and stocking density on fear and anxiety in broiler chickens. Animals 11(8), 2383.

Barren housing and high stocking densities may contribute to negative affective states in broiler chickens, reducing their welfare. We investigated the effects of environmental complexity and stocking density on broilers’ attention bias (measure of anxiety)...

Fernández-Lázaro, G., Dye, M. H., Eddie,C. et al. 2021. Strepsirrhine primate training programs in North American institutions: Status and implications for future welfare assessment. Animals 11(8), 2462.

Many articles have shown the benefits of operant conditioning training techniques in the care and welfare of several species of nonhuman primates; however, the information regarding their use in strepsirrhine species is scarce. We assessed...

Schwarzer, A., Plattner, C., Bergmann, S. et al. 2021. Feather pecking in non-beak-trimmed and beak-trimmed laying hens on commercial farms with aviaries. Animals 11(11), 3085.

Severe feather pecking (SFP) is a major animal welfare problem in layers. It results in pain and injuries in the affected animal. It was the aim of this study to gain insight into the actual...