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. 
Weaver, H. L., Carbaugh, C. M., Madejczyk, M. S. et al. 2024. Comparison of tricaine methanesulfonate (MS-222) and alfaxalone anesthesia in zebrafish (Danio rerio). JAALAS 63(1), 74–80.

The research use of zebrafish has risen exponentially over the past decade while anesthetic options have remained largely unchanged.6 ricaine methanesulfonate (MS-222) is widely accepted as an anesthetic for routine husbandry procedures, however it has...

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)...

Sen Sarma, O., Frymus, N., Axling, F. et al. 2023. Optimizing zebrafish rearing−Effects of fish density and environmental enrichment. Frontiers in Behavioral Neuroscience 17, 1204021.

Despite its popularity in research, there is very little scientifically validated knowledge about the best practices on zebrafish (Danio rerio) husbandry, which has led to several facilities having their own husbandry protocols. This study was...

Elane, G. L., Portela, D. A., Hobbs, K. J. et al. 2023. Sedated cesarean sections are associated with increased kid survival compared to general anesthesia in goats: Retrospective cohort of 45 cases (2011–2021). Journal of the American Veterinary Medical Association 261(3), 391–396.

OBJECTIVE To determine whether anesthesia type (sedation or general anesthesia) affects kid survival to discharge in caprine cesarean sections (C-sections). ANIMALS Retrospective cohort of 99 caprine C-sections (2011–2021). PROCEDURES All surgeries were performed via left...

Hanh, H. Q., Phuong, N. T., Tien, N. D. et al. 2023. Effects of stocking density in group cages on egg production, profitability, and aggressive pecking of hens. Journal of Applied Animal Welfare Science 26(3), 374–385.

There is an increasing concern about welfare issues related to battery cages, which are commonly used in Vietnam, and requires a modified cage that improves hen welfare while retaining its economic and management advantages. We...

Martin-Flores, M., Nugen, S. A., Boesch, J. M. et al. 2023. Low-dose epidural anesthesia decreases the use of intraoperative systemic analgesics in goats undergoing lower urinary tract surgery. Journal of the American Veterinary Medical Association 261(8), 1147–1151.

OBJECTIVE To test whether the use of low-dose epidural anesthesia (EA) in goats undergoing lower urinary tract surgery reduces the requirements of perioperative analgesics, contributes to intraoperative hypotension, and improves postoperative comfort during the first...

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...

Leyden, C., Brüggemann, T., Debinski, F. et al. 2022. Efficacy of tricaine (MS-222) and hypothermia as anesthetic agents for blocking sensorimotor responses in larval zebrafish. Frontiers in Veterinary Science 9, 864573.

Tricaine, or MS-222, is the most commonly used chemical anesthetic in zebrafish research. It is thought to act via blocking voltage-gated sodium channels, though its mechanism of action, particularly at the neuronal level, is not...

Mason, G. J., Lavery, J. M. 2022. What is it like to be a bass? Red herrings, fish pain and the study of animal sentience. Frontiers in Veterinary Science 9, 788289.

Debates around fishes’ ability to feel pain concern sentience: do reactions to tissue damage indicate evaluative consciousness (conscious affect), or mere nociception? Thanks to Braithwaite’s research leadership, and concerns that current practices could compromise welfare...

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...

Mumm, L. E., Mans, C. 2022. Evaluation of dexmedetomidine-midazolam sedation in budgerigars (Melopsittacus undulatus). Journal of the American Veterinary Medical Association 260(10), 1194–1199.

OBJECTIVE To evaluate the sedative effects of IM administration of a high or low dose of dexmedetomidine in combination with midazolam in budgerigars (Melopsittacus undulatus). ANIMALS 20 healthy adult budgerigars. PROCEDURES In a prospective, randomized...

Stracke, J., Volkmann, N., May, F. et al. 2021. Walking on tiptoes: Digital pads deserve increased attention when scoring footpad dermatitis as an animal welfare indicator in turkeys. Frontiers in Veterinary Science 7, 613516.

Animal welfare is one of the most challenging issues in modern farm animal husbandry. Animal welfare indicators can be used to monitor welfare on farms or at slaughterhouses, with footpad dermatitis (FPD) being one of...

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...

Owen, J. P., Kelsh, R. N. 2021. A suitable anaesthetic protocol for metamorphic zebrafish. PLOS ONE 16(3), e0246504.

Zebrafish are frequently used as a means to investigate development. These studies increasingly require repeated anaesthesia of zebrafish during juvenile (i.e. metamorphic) stages. The effects of anaesthesia during this time remain poorly studied. The aim...

Tahamtani, F. M., Herskin, M. S., Foldager, L. et al. 2021. Assessment of mobility and pain in broiler chickens with identifiable gait defects. Applied Animal Behaviour Science 234, 105183.

Gait defects, assessed as gait score (GS), is a common welfare problem in broiler chicken production. The aim of this study was to examine whether birds with GS2 experience pain and poor locomotor ability compared...

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...

Martini, A., Huysseune, A., Witten, P. E. et al. 2021. Plasticity of the skeleton and skeletal deformities in zebrafish (Danio rerio) linked to rearing density. Journal of Fish Biology 98(4), 971-986.

The teleost zebrafish (Danio rerio), an established model for human skeletal diseases, is reared under controlled conditions with defined parameters for temperature and photoperiod. Studies aimed at defining the proper rearing density have been performed...

Ellis, T., Katsiadaki, I. 2021. Clarification of early end-points for refinement of animal experiments, with specific reference to fish. Laboratory Animals 55(3), 244-253.

Appropriate end-points are integral to the refinement of laboratory animal experiments. Our recent experience has highlighted that ambiguity around end-points is hampering their adoption in experiments that cause severe suffering to fish. In toxicology, the...

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...

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)...

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...

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...

Jorge, S., Ferreira, J. M., Olsson, I. A. S. et al. 2021. Efficacy and behavioral recovery of different anesthetics. Zebrafish 18(5), 330-337.

The use of proper anesthesia in zebrafish research is essential to ensure fish welfare and data reliability. However, anesthesia long-term side effects remain poorly understood. The purpose of this study was to assess anesthesia quality...