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...

Robinson, L. M., Weiss, A. (Eds.) 2023. Nonhuman Primate Welfare: From History, Science, and Ethics to Practice. Springer, Cham, Switzerland. 671 p.

This volume reviews the broad topic of welfare in nonhuman primates under human care. Chapters detail the history of primates in captivity, ethical and legal issues surrounding the use of nonhuman primates as entertainment or...

Alig, B. N., Ferket, P. R., Malheiros, R. D. et al. 2023. The effect of housing environment on commercial brown egg layer production, USDA grade and USDA size distribution. Animals 13(4), 694

Consumer demand for retail cage-free eggs is driving the layer industry towards greater use of extensive housing environments. However, there is limited research on how these environments affect egg production characteristics of brown egg layers...

Almeida, M. M., Cabrita, E., Fatsini, E. 2023. The use of sand substrate modulates dominance behaviour and brain gene expression in a flatfish species. Animals 13(6), 978.

Physical complexity adds physical enrichment to rearing conditions. This enrichment promotes fish welfare and reduces detrimental characteristics that fish develop in captivity. Senegalese sole (Solea senegalensis) is an important species for European aquaculture, where it...

Brando, S., Vitale, A., Bacon, M. 2023. Promoting good nonhuman primate welfare outside regular working hours. Animals 13(8), 1423.

Promoting good primate welfare outside of daylight hours is an important task. The responsibility to provide a complex environment and environmental enrichment is an essential element of primate wellbeing programs that should be approached from...

da Silva, M. I. L., Paz, I. C. de L. A., Jacinto, A. S. et al. 2023. Providing environmental enrichments can reduce subclinical spondylolisthesis prevalence without affecting performance in broiler chickens. PLOS ONE 18(4), e0284087.

Environmental enrichment can increase the occurrence of natural behavior and improve leg health and other animal welfare outcomes in broiler chickens. This study aimed to assess the effects of three environmental enrichments, specifically hay bales...

Diao, W., Jia, R., Hou, Y. et al. 2023. Effects of stocking density on the growth performance, physiological parameters, antioxidant status and lipid metabolism of Pelteobagrus fulvidraco in the integrated rice-fish farming system. Animals 13(11), 1721.

Pelteobagrus fulvidraco is a freshwater fish commonly raised in rice fields, yet the optimal stocking density for this species remains unknown. Therefore, this study aimed to investigate the appropriate stocking density of P. fulvidraco in...

Dong, Y., Fraley, G. S., Siegford, J. M. et al. 2023. Comparing different environmental enrichments for improving the welfare and walking ability of male turkeys. PLOS ONE 18(5), e0285347.

This study investigated age-related changes in turkey welfare measures (wounds, feather quality (FQ), feather cleanliness, and footpad condition (FCON)) and walking ability (gait) as influenced by different types of environmental enrichment (EE). Tom turkeys (n...

Eeza, M. N. H., Singer, R., Ding, Y. et al. 2023. Probing microstructural changes in muscles of leptin-deficient zebrafish by non-invasive ex-vivo magnetic resonance microimaging. PLOS ONE 18(4), e0284215.

Leptin is a hormone that plays a key role in controlling food intake and energy homeostasis. Skeletal muscle is an important target for leptin and recent studies have shown that leptin deficiency may lead to...

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)...

Franks, B., Gaffney, L. P., Graham, C. et al. 2023. Curiosity in zebrafish (Danio rerio)? Behavioral responses to 30 novel objects. Frontiers in Veterinary Science 9, 1062420.

Curiosity—the motivation to seek out information—has been studied widely across the animal kingdom. To investigate curiosity in zebrafish we presented 30 novel objects to groups of zebrafish housed in semi-naturalistic tanks (6 tanks; 10 fish/tank...

Jorge, S., Félix, L., Costas, B. et al. 2023. Housing conditions affect adult zebrafish (Danio rerio) behavior but not their physiological status. Animals 13(6), 1120.

Zebrafish is a valuable model for neuroscience research, but the housing conditions to which it is exposed daily may be impairing its welfare status. The use of environmental enrichment and the refinement of methodology for...

Kleinhappel, T. K., Pike, T. W., Burman, O. H. P. 2023. Changes in group behaviour in response to a preferred environment reflect positive affect. Scientific Reports 13(1), 10576.

When observed in their preferred environments, animals display behavioural changes, such as an increase in resting or a reduction in agonism, suggestive of positive affect and improved welfare. However, most studies focus on the behaviour...

Krunt, O., Zita, L., Kraus, A. et al. 2023. Effects of genotype and housing system on rabbit does’ aggressive behaviors and injuries in smallholding conditions. Animals 13(8), 1357.

The objective of the study was to investigate the effects of housing (deep litter + concrete floor vs. deep litter + ground soil with the possibility to dig burrows), and genotype (Mecklenburg or Hyplus) on...

Matrai, E., Chan, H. Y. A., Leung, F. M. et al. 2023. Point for enrichment, point for welfare—Testing use of a laser pointer with Arapaima gigas. Animals 13(8), 1370.

The arapaima (Arapaima gigas) is one of the largest freshwater fish species, known to exceed 3 m in total length. It is listed as Data Deficient by the IUCN. A. gigas is native to the...

Moise, R. I., Eccles, G. R., Mettke-Hofmann, C. 2023. Enclosure background preferences differ between sexes and color morphs in the Gouldian finch. Animals 13(8), 1353.

Most wild animals camouflage well into their environment, providing protection from predators, whereas captive animals often contrast with their background. This can cause stress for the animal, which may perceive it as being exposed. Theory...

Morgado, J. N., Lamonaca, E., Santeramo, F. G. et al. 2023. Effects of management strategies on animal welfare and productivity under heat stress: A synthesis. Frontiers in Veterinary Science 10, 1145610.

Climate change includes different dramatic events, and among them, heat stress exposition is the strongest phenomenon affecting the livestock sector. The effects of heat stress events on animal welfare are complex and the economic impacts...

Paneru, B., Pent, G. J., Nastasi, S. et al. 2023. Effect of silvopasture system on fearfulness and leg health in fast-growing broiler chickens. PLOS ONE 18(3), e0282923.

A silvopasture system intentionally integrates trees, forages, and livestock, allowing dual land use. These systems can provide high-quality habitat for broiler chickens; however, such systems have not been widely adopted by the broiler industry in...

Peruga, M., Kawala, B., Sarul, M. et al. 2023. Are currently selected laboratory animals useful in the research of how female hormones influence orthodontic biomechanics? Animals 13(4), 629.

Animal testing was and remains the only method of introducing a certain treatment and medical procedure on humans. On the other hand, animals have their rights resulting from applicable legal acts, including Directive 2010/63/EU and...

Scatterty, K. R., Pitman, T., Eckersley, T. et al. 2023. Zebrafish aversion to infrasound in an open field test. Frontiers in Behavioral Neuroscience 16, 1019368.

Aquatic species are capable of detecting infrasound (sub-20 Hz frequencies) which may be a source of anthropogenic pollution and have a detrimental impact on the environmental fitness of fish. Infrasound is generated by infrastructure, producing...

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...

Skånberg, L., Newberry, R. C., Estevez, I. et al. 2023. Environmental change or choice during early rearing improves behavioural adaptability in laying hen chicks. Scientific Reports 13(1), 6178.

Laying hens are typically moved to a novel environment after rearing, requiring adaptability to cope with change. We hypothesized that the standard rearing of laying hen chicks, in non-changing environments with limited choices (a single...

Sokołowicz, Z., Dykiel, M., Topczewska, J. et al. 2023. A comparison of the plumage condition of three egg-laying poultry genotypes housed in non-cage systems. Animals 13(2), 185.

The study covered a total of 810 hens in 3 groups (housing systems) of 270 hens each. The plumage condition of laying hens raised in various types of alternative housing systems, i.e., in deep litter...

Zieliński, D. 2023. The effect of enrichment on leopard geckos (Eublepharis macularius) housed in two different maintenace systems (rack system vs. Terrarium). Animals 13(6), 1111.

The aim of this study was to test the usefulness of environmental enrichment for Eublepharis macularius depending on the maintenance method (terrarium vs. rack system). The hypothesis was that reptiles kept in an extremely low-stimulus...

Buenhombre, J., Daza-Cardona, E. A., Sousa, P. et al. 2023. Structural environmental enrichment and the way it is offered influence cognitive judgement bias and anxiety-like behaviours in zebrafish. Animal Cognition 26, 563–577.

Environmental enrichment in zebrafish generally reduces anxiety-related behaviours, improves learning in maze trials and increases health and biological fitness. However, certain types of enrichment or certain conditions induce the opposite effects. Therefore, it is essential...