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. 
Kittelsen, K. E., Gretarsson, P., Jensen, P. et al. 2021. Keel bone fractures are more prevalent in White Leghorn hens than in Red Jungle fowl hens—A pilot study. PLOS ONE 16(7), e0255234.

Fractures and deviations to the keel bone are common in commercial laying hens, with reported variations in occurrence across strains and breeds. The aetiology is not fully understood, however, modern genetics and selection for efficient...

Dalla Costa, E., Dai, F., Lecchi, C. et al. 2021. Towards an improved pain assessment in castrated horses using facial expressions (HGS) and circulating miRNAs. Veterinary Record 188(9), e82.

Background: Pain in horses is an emergent welfare concern, and its assessment represents a challenge for equine clinicians. This study aimed at improving pain assessment in horses through a convergent validation of existing tools: we...

Hausberger, M., Lesimple, C., Henry, S. 2021. Detecting welfare in a non-verbal species: Social/cultural biases and difficulties in horse welfare assessment. Animals 11(8), 2249.

Horses were domesticated for more than 5000 years and have been one of the most emblematic species living alongside humans. This long-shared history would suggest that horses are well known and well understood, but scientific...

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)...

Kolarevic, J., Calduch-Giner, J., Espmark, Å. M. et al. 2021. A novel miniaturized biosensor for monitoring Atlantic salmon swimming activity and respiratory frequency. Animals 11(8), 2403.

The advanced development of sensor technologies has led to the emergence of fish biosensors that are currently used for research and commercial purposes. AEFishBIT is a miniaturized biosensor attached to fish operculum that measures physical...

Travain, T., Valsecchi, P. 2021. Infrared thermography in the study of animals’ emotional responses: A critical review. Animals 11(9), 2510.

Whether animals have emotions was historically a long-lasting question but, today, nobody disputes that they do. However, how to assess them and how to guarantee animals their welfare have become important research topics in the...

Wang, G., Muhammad, A., Liu, C. et al. 2021. Automatic recognition of fish behavior with a fusion of RGB and optical flow data based on deep learning. Animals 11(10), 2774.

The rapid and precise recognition of fish behavior is critical in perceiving health and welfare by allowing farmers to make informed management decisions on recirculating aquaculture systems while reducing labor. The conventional recognition methods are...

Prior, H., Blunt, H., Crossman, L. et al. 2021. Refining procedures within regulatory toxicology studies: Improving animal welfare and data. Animals 11(11), 3057.

During the development of potential new medicines or agrochemicals, an assessment of the safety profile to humans and environmental species is conducted using a range of different in silico and in vitro techniques in conjunction...

Diana, A., Salas, M., Pereboom, Z. et al. 2021. A systematic review of the use of technology to monitor welfare in zoo animals: Is there space for improvement? Animals 11(11), 3048.

A top priority of modern zoos is to ensure good animal welfare (AW), thus, efforts towards improving AW monitoring are increasing. Welfare assessments are performed through more traditional approaches by employing direct observations and time-consuming...

Forslind, S., Blokhuis, H. J., Riber, A. B. 2021. Disturbance of resting behaviour of broilers under different environmental conditions. Applied Animal Behaviour Science 242, 105425.

Resting behaviours make up a large part of the daily time budget of broilers. However, in intensive broiler production systems disruptions of resting behaviours occur, where resting individuals get disturbed by active individuals. Such interruptions...

Neethirajan, S. 2021. The use of artificial intelligence in assessing affective states in livestock. Frontiers in Veterinary Science 8, 715261.

In order to promote the welfare of farm animals, there is a need to be able to recognize, register and monitor their affective states. Numerous studies show that just like humans, non-human animals are able...

da Silva Medeiros Elidio, H., Coelho, J. W. R., Cavalcanti Pereira da Silva, L. C. et al. 2021. Housing density and aggression in Syrian hamsters. JAALAS 60(5), 506-509.

The Syrian hamster (Mesocricetus auratus) is a solitary and naturally territorial animal, with female hamsters being more aggressive than males. This behavior makes handling difficult because they are usually housed in groups, which can lead...

Lencioni, G. C., de Sousa, R. V., de Souza Sardinha, E. J. et al. 2021. Pain assessment in horses using automatic facial expression recognition through deep learning-based modeling. PLOS ONE 16(10), e0258672.

The aim of this study was to develop and evaluate a machine vision algorithm to assess the pain level in horses, using an automatic computational classifier based on the Horse Grimace Scale (HGS) and trained...

Sabrautzki, S., Miller, M., Kague, E. et al. 2021. Welfare assessment of adult laboratory zebrafish: A practical guide. Zebrafish 18(4), 282-292.

Teleost fish such as Danio rerio (zebrafish) have been successfully used in biomedical research since decades. Genetically altered fish lines obtained by state-of-the-art genetic technologies are serving as well-known model organisms. In Europe, following Directive...

Andersson, M., Kettunen, P. 2021. Effects of holding density on the welfare of zebrafish: A systematic review. Zebrafish 18(5), 297-306.

The zebrafish is becoming an increasingly popular research animal around the world. Its welfare is affected by an array of environmental factors, such as food access and water quality. Holding density is an important welfare...

Kalafut, K. L., Kinley, R. 2020. Using radio frequency identification for behavioral monitoring in little blue penguins. Journal of Applied Animal Welfare Science 23(1), 62-73.

A common goal of captive animal institutions is to create environments that allow for the most naturalistic behavior from their animals. Behavioral data is often used as a measure of how an animal is thriving...

Piller, A., Bergmann, S., Schwarzer, A. et al. 2020. Validation of histological and visual scoring systems for foot-pad dermatitis in broiler chickens. Animal Welfare 29(2), 185-196.

In this study, an appropriate visual scoring system for foot-pad dermatitis was validated, considering the histologically measured depth of the inflammation zone and the histopathological grade (no lesion, mild lesion, ulcer). The aim being to...

Jones, P., Tahamtani, F., Pedersen, I. et al. 2020. The productivity and financial impacts of eight types of environmental enrichment for broiler chickens. Animals 10(3), 378.

Reduced mobility in broilers can contribute to leg health problems. Environmental enrichment has been suggested as one approach to combat this through stimulating increased physical activity. Past studies have tested the effect of environmental enrichments...

Baker, S. L., Robison, C. I., Karcher, D. M. et al. 2020. Keel impacts and associated behaviors in laying hens. Applied Animal Behaviour Science 222, 104886.

Factors contributing to the development of keel bone damage are not well understood. This study aimed to identify behaviors and cage structures associated with acceleration events experienced by individual hens at their keels as the...

Thøfner, I., Hougen, H. P., Villa, C. et al. 2020. Pathological characterization of keel bone fractures in laying hens does not support external trauma as the underlying cause. PLOS ONE 15(3), e0229735.

Keel bone fractures in laying hens have been described with increasing prevalence from several countries over the last twenty years and are considered one of the greatest welfare problems to the layer industry. In Denmark...

Armstrong, E. A., Rufener, C., Toscano, M. J. et al. 2020. Keel bone fractures induce a depressive-like state in laying hens. Scientific Reports 10(1), 3007.

In commercial flocks of laying hens, keel bone fractures (KBFs) are prevalent and associated with behavioural indicators of pain. However, whether their impact is severe enough to induce a depressive-like state of chronic stress is...

Marcantonio Coneglian, M., Duarte Borges, T., Henrique Weber, S. et al. 2020. Use of the horse grimace scale to identify and quantify pain due to dental disorders in horses. Applied Animal Behaviour Science 225, 104970.

Dental disorders can cause discomfort and chronic pain, affecting the athletic performance and welfare of the horses. However, dental disorders may not be manifested with recognizable clinical signs and may, therefore, lead to late diagnosis...

Padalino, B., Raidal, S. 2020. Effects of transport conditions on behavioural and physiological responses of horses. Animals 10(1), 160.

The regulations for minimal space and direction of travel for land transport in horses vary worldwide and there is currently no definitive guidance to promote equine health and welfare. This study evaluated the effects of...

Torcivia, C., McDonnell, S. 2020. In-person caretaker visits disrupt ongoing discomfort behavior in hospitalized equine orthopedic surgical patients. Animals 10(2), 210.

Horses have evolved to show little indication of discomfort or disability when in the presence of potential predators, including humans. This natural characteristic complicates the recognition of pain in equine patients. It has been our...

Lesimple, C. 2020. Indicators of horse welfare: State-of-the-art. Animals 10(2), 294.

Animal welfare is defined as a chronic state reflecting an individual’s subjective perception of its situation. Because it is possible to be in a good welfare state and nevertheless experience acute fear or pain, and...