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. 
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)...

Pereira, E., Nääs, I. de A., Ivale, A. H. et al. 2023. Energy assessment from broiler chicks’ vocalization might help improve welfare and production. Animals 13(1), 15.

Vocalization seems to be a viable source of signal for assessing broiler welfare. However, it may require an understanding of the birds’ signals, both quantitatively and qualitatively. The delivery of calls with a specific set...

Wong, C.-H., Tsai, M.-A., Ko, F.-C. et al. 2023. Skin cortisol and acoustic activity: Potential tools to evaluate stress and welfare in captive cetaceans. Animals 13(9), 1521.

As people’s focus broadens from animals on farms to zoos and aquaria, the field of welfare science and the public’s concern for animal welfare continue to grow. In captive animals, stress and its causes are...

Baskir, E., Parsons, A., Elden, M. et al. 2023. Quantifying acute behavioral reactions of Bali mynas (Leucopsar rothschildi) to environmental and progressively challenging enrichment. Journal of Zoological and Botanical Gardens 4(1), 176–190.

Animals use specific behaviors and skills to overcome challenges and access resources. Environmental enrichment is provided to animals in human care to both promote species-appropriate behaviors and reduce undesired behaviors. Feather pecking in birds is...

Olczak, K., Penar, W., Nowicki, J. et al. 2023. The role of sound in livestock farming—Selected aspects. Animals 13(14), 2307.

To ensure the optimal living conditions of farm animals, it is essential to understand how their senses work and the way in which they perceive their environment. Most animals have a different hearing range compared...

Riemer, S. 2023. Therapy and prevention of noise fears in dogs—A review of the current evidence for practitioners. Animals 13(23), 3664.

Noise fears represent the most common behavioural problem in dogs. This manuscript provides an overview of diverse approaches for alleviating fear of noises in dogs and the supporting evidence. In the treatment of noise fears...

van Zeeland, Y. R. A., Schoemaker, N. J., Lumeij, J. T. 2023. Contrafreeloading indicating the behavioural need to forage in healthy and feather damaging Grey parrots. Animals 13(16), 2635.

Contrafreeloading (CFL) is a concept that describes the preference of an animal to work for food even when identical food is freely available, and reflects an intrinsic motivation to engage in foraging-related activities. However, altered...

Goldsborough, Z., Sterck, E. H. M., de Waal, F. B. M. et al. 2022. Individual variation in chimpanzee (Pan troglodytes) repertoires of abnormal behaviour. Animal Welfare 31(1), 125-135.

Abnormal behaviour in captive animals is both pervasive and ambiguous. Although individual differences are central to the field of animal welfare, studies on abnormal behaviour predominantly employ quantitative, population-level approaches. For example, whereas previous studies...

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...

Knaebe, B., Weiss, C. C., Zimmermann, J. et al. 2022. The promise of behavioral tracking systems for advancing primate animal welfare. Animals 12(13), 1648.

Recent years have witnessed major advances in the ability of computerized systems to track the positions of animals as they move through large and unconstrained environments. These systems have so far been a great boon...

Houstin, A., Zitterbart, D. P., Winterl, A. et al. 2022. Biologging of emperor penguins—Attachment techniques and associated deployment performance. PLOS ONE 17(8), e0265849.

An increasing number of marine animals are equipped with biologgers, to study their physiology, behaviour and ecology, often for conservation purposes. To minimise the impacts of biologgers on the animals’ welfare, the Refinement principle from...

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...

Wilson, C. H., Wyeth, R. C., Spicer, J. I. et al. 2022. Effect of animal stocking density and habitat enrichment on survival and vitality of wild green shore crabs, Carcinus maenas, maintained in the laboratory. Animals 12(21), 2970.

The wide geographic distribution, large size and ease of capture has led to decapod crustaceans being used extensively in laboratory experiments. Recently in the United Kingdom decapod crustaceans were listed as sentient beings, resulting in...

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...

Ginovart-Panisello, G. J., Iriondo Sanz, I., Panisello Monjo, T. et al. 2022. Trend and representativeness of acoustic features of broiler chicken vocalisations related to CO2. Applied Sciences 12(20), 10480.

The concentration of CO2 is relatively large in poultry farms and high accumulations of this gas reduce animal welfare. Good control of its concentration is crucial for the health of the animals. The vocalizations of...

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...

Serres, A., Xu, C., Hao, Y. et al. 2021. The click production of captive Yangtze finless porpoises (Neophocaena asiaeorientalis asiaorientalis) is influenced by social and environmental factors. Animals 11(2), 511.

Yangtze finless porpoises use high-frequency clicks to navigate, forage, and communicate. The way in which click production may vary depending on social or environmental context has never been investigated. A group of five captive Yangtze...

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...

Marx, A., Lenkei, R., Pérez Fraga, P. et al. 2021. Occurrences of non-linear phenomena and vocal harshness in dog whines as indicators of stress and ageing. Scientific Reports 11(1), 4468.

During social interactions, acoustic parameters of tetrapods’ vocalisations reflect the emotional state of the caller. Higher levels of spectral noise and the occurrence of irregularities (non-linear phenomena NLP) might be negative arousal indicators in alarm...

Prior, H., Holbrook, M. 2021. Strategies to encourage the adoption of social housing during cardiovascular telemetry recordings in non-rodents. Journal of Pharmacological and Toxicological Methods 108, 106959.

The National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) is working with industry to promote social housing during cardiovascular telemetry recordings within non-rodent safety pharmacology and toxicology studies. Following surveys...

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...

Spiezio C., Vaglio, S., Vandelle C. et al. 2021. Effects of rearing on the behaviour of zoo-housed chimpanzees (Pan troglodytes). Folia Primatologica 92(2), 91–102.

Early-life experiences may considerably affect the behavioural patterns of adult primates. Particularly, atypical rearing practices might lead to abnormal behaviours and social-sexual deficiencies in captive, adult non-human primates. We conducted behavioural observations of mother-reared (n...