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. 
Correia de Lima Almeida Paz, I., Correia de Lima Almeida, I., Milbradt, E. L. et al. 2019. Effects of analgesic and noise stimulus in gait score assessment. PLOS ONE 14(1), e0208827.

This experiment was carried out aiming to assess walking manner and speed of broiler chickens with different gait scores (GS), with or without sound stimulus, and with or without administration of analgesic. To that end...

Ross, M., Garland, A., Harlander-Matauschek, A. et al. 2019. Welfare-improving enrichments greatly reduce hens' startle responses, despite little change in judgment bias. Scientific Reports 9, 11881.

Responses to ambiguous and aversive stimuli (e.g. via tests of judgment bias and measures of startle amplitude) can indicate mammals’ affective states. We hypothesised that such findings generalize to birds, and that these two responses...

Jung, L., Knierim, U. 2019. Differences between feather pecking and non-feather pecking laying hen flocks regarding their compliance with recommendations for the prevention of feather pecking – A matched concurrent case-control design. Applied Animal Behaviour Science 219, 104839.

Feather pecking (FP) is a multifactorial problem in all housing systems. Using a case-control design we wanted to determine a set of variables which may be decisive for a flock to become case or control...

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...

Machado, M., Oliveira da Silva, I. J. 2019. Does farm animals experience emotions and feelings? Journal of Animal Behaviour and Biometeorology 7(4), 170-175.

In recent years, there has been a great increase in the interest of "emotion" and how it can be studied and translated from animals. Emotions arise when the brain receives an external stimulus, while the...

Andrianov, E. A., Sudakov, A. N., Andrianov, A. A. et al. 2019. Non-invasive monitoring of avian embryo heart rate. Journal of Animal Behaviour and Biometeorology 7(3), 119-122.

Non-invasive monitoring of the heart rate allows measuring the condition of the chick embryo in the incubation process without negative consequences for the future chick. The optical method for registering heartbeats is available to a...

Fischer, C. P., Romero, L. M. 2019. Chronic captivity stress in wild animals is highly species-specific. Conservation Physiology 7(1), coz093.

Wild animals are brought into captivity for many reasons—conservation, research, agriculture and the exotic pet trade. While the physical needs of animals are met in captivity, the conditions of confinement and exposure to humans can...

Špinka, M. 2019. Animal agency, animal awareness and animal welfare. Animal Welfare 28(1), 11–20.

In nature, animals need to actively engage with the environment in order to prosper in survival and reproduction. Hence, agency is a central adaptive characteristic of animal life. In this paper, I propose that from...

Eusemann, B. K., Baulain, U., Schrader, L. et al. 2018. Radiographic examination of keel bone damage in living laying hens of different strains kept in two housing systems. PLOS ONE 13(5), e0194974.

A high prevalence of deviations and fractures of the keel bone is a widespread welfare problem in laying hens. The aim of this study was to experimentally investigate this multifactorial problem throughout the laying period...

McIlhone, A. E., Beausoleil, N. J., Kells, N. J. et al. 2018. Effects of noxious stimuli on the electroencephalogram of anaesthetised chickens (Gallus gallus domesticus). PLOS ONE 13(4), e0196454.

The reliable assessment and management of avian pain is important in the context of animal welfare. Overtly expressed signs of pain vary substantially between and within species, strains and individuals, limiting the use of behaviour...

Toscano, M., Booth, F., Richards, G. et al. 2018. Modeling collisions in laying hens as a tool to identify causative factors for keel bone fractures and means to reduce their occurrence and severity. PLOS ONE 13(7), e0200025.

Keel fractures represent a major productivity and welfare issue for the laying hen industry with greater than 50% of birds in recent surveys across various commercial operations and nations exhibiting some form of damage by...

Riddle, E. R., Ali, A. B. A., Campbell, D. L. M. et al. 2018. Space use by 4 strains of laying hens to perch, wing flap, dust bathe, stand and lie down. PLOS ONE 13(1), e0190532.

The laying hen industry is implementing aviary systems intended to improve welfare by providing hens with more space and resources to perform species-specific behaviors. To date, limited research has examined spatial requirements of various strains...

Souza, A., Soriano, V. S., Schnaider, M. A. et al. 2018. Development and refinement of three animal-based broiler chicken welfare indicators. Animal Welfare 27(3), 263-274.

This study aimed to refine bird-soiling as a broiler chicken (Gallus gallus domesticus) welfare indicator, and to develop and test two additional indicators, namely contact dermatitis on the breast and abdominal areas and carcase scratches...

Casey-Trott, T. M., Widowski, T. M. 2018. Validation of an accelerometer to quantify inactivity in laying hens with or without keel-bone fractures. Animal Welfare 27(2), 103-114.

Accelerometers are used to remotely monitor activity in various species in studies that quantify pain, document behavioural patterns, and measure individual activity differences. Studies validating accelerometers typically quantify various active states; however, targeting states specific...

Carter, E. 2018. Updated Code of Practice for the welfare of meat chickens and meat breeding chickens in England. Animal Welfare 27(2), 181-185.

Much of the content in the 2018 Code is similar to that found in previous guidance documents: the 2002 Code of Practice for the Welfare of Meat Chickens and Meat Breeding Chickens, and the 2011...

Jansson, D.S. 2018 Gaining insights into the health of non-caged layer hens. Veterinary Record 182(12), 347-349.

To prevent injuries and mortality in commercial non-caged laying hens a range of strategies should be used, including vaccination, effective biosecurity routines, optimal management and nutrition. Injurious pecking, footpad lesions, keel bone fractures, reproductive and...

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...

Cooke, G. M. 2018. Use of a translucent refuge for Xenopus tropicalis with the aim of improving welfare. Laboratory Animals 52(3), 304-307.

Xenopus tropicalis is an increasingly important animal model in a variety of biological research fields. In many countries legislation exists to promote and increase welfare wherever possible, including the ability to view animals during daily...

Bacon, H. 2018. Behaviour-based husbandry—A holistic approach to the management of abnormal repetitive behaviors. Animals 8(7), 103.

The field of zoo animal welfare science has developed significantly over recent years. However despite this progress in terms of scientific research, globally, zoo animals still face many welfare challenges. Recently, animal welfare frameworks such...

Clegg, I. 2018. Cognitive bias in zoo animals: An optimistic outlook for welfare assessment. Animals 8(7), 104.

Cognitive bias testing measures how emotional states can affect cognitive processes, often described using the “glass half-full/half-empty” paradigm. Classical or operant conditioning is used to measure responses to ambiguous cues, and it has been reported...

Wolfensohn, S., Shotton, J., Bowley, H. et al. 2018. Assessment of welfare in zoo animals: Towards optimum quality of life. Animals 8(7), 110.

Zoos are required to maintain a high standard of animal welfare, and this can be assessed using a combination of resource-based and animal-based indices usually divided into behavioural indicators, physiological indicators and clinical/pathological signs. Modern...

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...

Benson, E., Weiher, J., Alphin, R. et al. 2018. Evaluation of two compressed air foam systems for culling caged layer hens. Animals 8(5), 61.

Outbreaks of avian influenza (AI) and other highly contagious poultry diseases continue to be a concern for those involved in the poultry industry. In the situation of an outbreak, emergency depopulation of the birds involved...