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...

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)...

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...

Scariot, P. P., Gobatto, C. A., Polisel, E. E. et al. 2022. Early-life mice housed in standard stocking density reduce the spontaneous physical activity and increase visceral fat deposition before reaching adulthood. Laboratory Animals 56(4), 344-355.

Laboratory rodents spend the entire day housed in standard cages that provide a restricted area for movements and might, therefore, limit physical activity. However, it has not been tested in immature rodents of ages ranging...

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...

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...

Krueger, L. D., Chang, S. E., Motoc, M. et al. 2021. Effects of pair housing on patency of jugular catheters in rats (Rattus norvegicus). JAALAS 60(3), 357-364.

Chronic vascular access devices are widely used in a variety of species for repeated blood sampling or substance administration. Jugular catheters are commonly used for studying addiction-related behaviors in rats. Rats with catheters have historically...

Koch, A. L., Rusnak, M., Peachee, K. et al. 2021. Comparison of the effects of osmotic pump implantation with subcutaneous injection for administration of drugs after total body irradiation in mice. Laboratory Animals 55(2), 142-149.

The increasing potential for radiation exposure from nuclear accidents or terrorist activities has intensified the need to develop pharmacologic countermeasures against injury from total body irradiation (TBI). Many initial experiments to develop and test these...

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)...

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...

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...

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...

Van Wijk, H., Haida, D., Duncan, C. et al. 2020. Surgery refinements improve success rates in rat bile collection. Animal Technology and Welfare 19(3), 251-254.

This poster compares the model success rates using 2 different housing regimes during recovery from surgery. Catheters were placed in the bile duct to collect bile; a second catheter was secured into the duodenum where...

Pedersen, I. J., Forkman, B. 2019. Improving leg health in broiler chickens: A systematic review of the effect of environmental enrichment. Animal Welfare 28(2), 215-230.

Leg problems are highly prevalent in modern broiler production and provision of environmental enrichment could be a strategy to improve leg health. Different types of environmental enrichment have undergone evaluation. Our objective was to conduct...

Falkenberg, M. K., Teilmann, A. C., Henriksen, T. et al. 2019. Clinical, physiologic, and behavioral evaluation of permanently catheterized NMRI mice. JAALAS 58(3), 380-389.

Vascular catheterization is becoming a popular technique in laboratory rodents, facilitating repetitive blood sampling and infusion in individual animals. In mice, catheterization is complicated by their small body size, which may increase the risk of...

Nosaka, N., Crother, T. R., Chen, S. et al. 2019. Optimal tube length of orotracheal intubation for mice. Laboratory Animals 53(1), 79–83.

Endotracheal tube (ETT) management is an essential technique in handling mice with mechanical ventilators. Malposition into bronchi causes not only lethal complications for them but also less efficient mechanical ventilation. However, in general, it is...

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...

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...

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...

Santurtun, E., Broom, D. M., Phillips, C. J. C. 2018. A review of factors affecting the welfare of Atlantic salmon (Salmo salar). Animal Welfare 27(3), 193-204.

In the expanding salmon industry, many farmers use production methods that could result in poor welfare of the fish at various points of their lifecycle. We have reviewed methods used for producing salmon for food...

van Wijk, H., Crossman, L., Adjin-Tettey, G. et al. 2018. Advances in animal welfare and scientific outcomes of the bile duct cannulated rat model utilised in ADME studies. Animal Technology and Welfare 17(1), 64-67.

Since rats lack a gall bladder, they are an ideal model for investigating continuous biliary excretion and biotransformation. The design and implementation of a modified tail cuff and cannula system introduced at Covance permits the...

Bailoo, J. D., Murphy, E., Varholick, J. A. et al. 2018. Evaluation of the effects of space allowance on measures of animal welfare in laboratory mice. Scientific Reports 8, 713.

We studied how space allowance affects measures of animal welfare in mice by systematically varying group size and cage type across three levels each in both males and females of two strains of mice (C57BL/6ByJ...

Zepp, M., Louton, H., Erhard, M. et al. 2018. The influence of stocking density and enrichment on the occurrence of feather pecking and aggressive pecking behavior in laying hen chicks. Journal of Veterinary Behavior 24, 9-18.

The housing conditions and environments experienced during the rearing period can influence the development of feather pecking in chickens during this time and in the subsequent laying period. The aim of this study was to...