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. 
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...

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...

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...

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...

Hernández-Arteaga, E., Ågmo, A. 2023. Seminatural environments for rodent behavioral testing: A representative design improving animal welfare and enhancing replicability. Frontiers in Behavioral Neuroscience 17, 1192213.

The low replicability of scientific studies has become an important issue. One possible cause is low representativeness of the experimental design employed. Already in the 1950’s, Egon Brunswick pointed out that experimental setups ideally should...

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...

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...

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...

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...

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...

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...

Vas, J., BenSassi, N., Vasdal, G. et al. 2023. Better welfare for broiler chickens given more types of environmental enrichments and more space to enjoy them. Applied Animal Behaviour Science 261, 105901.

Providing an increased variety of environmental enrichment options, with sufficient space to use them, could increase the behavioural expression of positive affective states in production animals. The goal of this study was to investigate associations...

Beekmans, M. H. C., Vinke, C. M., Maijer, A. et al. 2023. Increasing foraging times with appetitive and consummatory foraging enrichment in grey parrots (Psittacus erithacus). Applied Animal Behaviour Science 265, 105986.

Foraging enrichment is considered one of the most effective ways to enhance expression of species-typical behaviours and prevent the development of abnormal (repetitive) behaviours in captive animals. However, foraging enrichments for parrots have thus far...

Lobina, C., Maccioni, P., Gessa, G. L. et al. 2023. Exposure to an enriched environment exerts anxiolytic effects in Sardinian alcohol-preferring rats. Behavioural Brain Research 452, 114557.

Exposure to an enriched environment (EE) has been reported to generate multiple beneficial effects in rodents, including – among the many – amelioration of anxiety-related behaviors. The present study investigated whether living in an EE...

Meira, J. E. S., Nogueira-Filho, S. L. G., Mendl, M. et al. 2023. Responses to environmental enrichment are associated with personality characteristics in chestnut-bellied seed finches (Sporophila angolensis). Behavioural Processes 204, 104801.

Environmental enrichment (EE) is used to promote natural behaviours in captive animals and may hold promise as a form of pre-release training, a strategy for improving coping skills of translocated birds. We investigated the use...

Núñez-Murrieta, M. A., Coria-Avila, G. A., Martínez, A. J. et al. 2023. Preterm rat survival is enhanced by gestational environmental enrichment. Behavioural Processes 205, 104820.

Throughout the last decade, the estimated global human preterm birth rate was 10.6 %, with higher rates in Asia, South America, and Africa. Preterm individuals, even in adulthood, are more likely to develop cardiorespiratory, renal...

Baskir, E., Parsons, A., Elden, M. et al. 2023. Quantifying acute behavioral reactions of Bali mynas (Leucopsar rothschildi) to environmental and progressively challenging enrichment. Journal of Zoological and Botanical Gardens 4(1), 176–190.

Animals use specific behaviors and skills to overcome challenges and access resources. Environmental enrichment is provided to animals in human care to both promote species-appropriate behaviors and reduce undesired behaviors. Feather pecking in birds is...

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(2), 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...

Fuller, G., Jones, M., Gartland, K. N. et al. 2023. The benefits of increased space and habitat complexity for the welfare of zoo-housed king penguins (Aptenodytes patagonicus). Animals 13(14), 2312.

Zoos and aquariums accredited by the Association of Zoos and Aquariums embrace animal welfare as a foundational principle of habitat design. Modern habitats are designed to provide animals with choices and agency over their environment...

Grandin, T. 2023. A practical approach to providing environmental enrichment to pigs and broiler chickens housed in intensive systems. Animals 13(14), 2372.

In Europe, regulations contain guidance to maintain high standards of animal welfare. In many parts of the world, large buyers for supermarkets or restaurants are the main enforcers of basic animal welfare standards. They can...

Mählis, G., Kleine, A., Lüschow, D. et al. 2023. Clicker training as an applied refinement measure in chickens. Animals 13(24), 3836.

When using chickens in animal studies, the handling of these animals for sample collection or general examinations is considered stressful due to their prey nature. For the study presented here, plasma and salivary corticosterone as...

Mair, A., Dadda, M., Kitaoka, A. et al. 2023. Illu-shoal choice: An exploration of different means for enrichment of captive zebrafish. Animals 13(16), 2640.

Fish of any variety are nowadays being kept captive for several purposes, from recreational to alimentary to research. It is possible that we humans often underestimate or misunderstand the basic, natural needs of the species...