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...

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...

Holland, A., Galardi, E. G., Fabbroni, M. et al. 2023. Exploration of social proximity and behavior in captive malayan tigers and their cubs. Animals 13(6), 1040.

NHP,Other primate

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...

Pallieres, C. G. D., Rose, P. E. 2023. Two’s company, three species is a crowd? A webcam-based study of the behavioural effects of mixed-species groupings in the wild and in the zoo. PLOS ONE 18(4), e0284221.

Mixed species exhibits in zoos are used to create larger, more stimulating environments to support naturalistic interactions between species. In the wild, mixed species groups are observed as having lower rates of vigilance, presumably due...

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...

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...

Goswami, S., Tyagi, P. C., Malik, P. K. et al. 2023. Effects of enclosure complexity and visitor presence on the welfare of Asiatic lions. Applied Animal Behaviour Science 260, 105853.

In recent years, there has been much research into the individual effects of enclosure complexity and visitor presence on captive animal welfare. However, the inter-linkages between enclosure complexity and visitor presence and their combined influence...

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...

Montalcini, C. M., Petelle, M. B., Toscano, M. J. 2023. Commercial hatchery practices have long-lasting effects on laying hens’ spatial behaviour and health. PLOS ONE 18(12), e0295560.

The commercial hatchery process is globally standardized and exposes billions of day-old layer chicks to stress every year. By alleviating this early stress, on-farm hatching is thought to improve animal welfare, yet little is known...

Rana, M. S., Lee, C., Lea, J. M. et al. 2022. Commercial free-range laying hens’ preferences for shelters with different sunlight filtering percentages. Animals 12(3), 344.

Extreme sunlight might be aversive to free-range laying hens, discouraging them from going outside. Range enrichment with artificial shelters may protect hens from sunlight and increase range use. The preferences of 34–40-week-old Hy-Line Brown laying...

Mels, C., Niebuhr, K., Futschik, A. et al. 2022. Predictors for plumage damage and bloody lesions indicative of feather pecking in pullets reared in aviaries. Applied Animal Behaviour Science 250, 105607.

Feather pecking remains a serious problem in poultry farming. This study aimed to identify risk factors for plumage damage as a proxy for feather pecking, and the predictive value of practical animal-based parameters. Data were...

Bertoni, V., Spiezio, C., Regaiolli, B. et al. 2022. Group reunion in zoo European wildcats using cat appeasing pheromone (CAP) and gradual release of the animals in the exhibit—A case study. Animals 12(10), 1302.

The union or reunion of animals with social groups can be a challenging situation, and little has been published about it when solitary species are concerned. Therefore, the aim of the present study was two-fold...

Campbell, A. M., Johnson, A. M., Persia, M. E. et al. 2022. Effects of housing system on anxiety, chronic stress, fear, and immune function in Bovan brown laying hens. Animals 12(14), 1803.

The scientific community needs objective measures to appropriately assess animal welfare. The study objective was to assess the impact of housing system on novel physiological and behavioral measurements of animal welfare for laying hens, including...

Lee, V. E., Arnott, G., Turner, S. P. 2022. Social behavior in farm animals: Applying fundamental theory to improve animal welfare. Frontiers in Veterinary Science 9, 932217.

A fundamental understanding of behavior is essential to improving the welfare of billions of farm animals around the world. Despite living in an environment managed by humans, farm animals are still capable of making important...

Bonnefous, C., Collin, A., Guilloteau, L. A. et al. 2022. Welfare issues and potential solutions for laying hens in free range and organic production systems: A review based on literature and interviews. Frontiers in Veterinary Science 9, 952922.

In free-range and organic production systems, hens can make choices according to their needs and desires, which is in accordance with welfare definitions. Nonetheless, health and behavioral problems are also encountered in these systems. The...

Liao, S.-C., Lyu, P.-X., Shen, S.-Y. et al. 2022. Effects of swimming pool conditions and floor types on white roman geese’s physical condition scores and behaviors in an indoor rearing system. Animals 12(23), 3273.

Biosecurity problems, including the continual risk of avian influenza spread by wild birds, have severely affected traditional free-range waterfowl production systems. Regulations and techniques for indoor goose production require more considerations for animal welfare. This...

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...

Schuck-Paim, C., Negro-Calduch, E., Alonso, W. J. 2021. Laying hen mortality in different indoor housing systems: A meta-analysis of data from commercial farms in 16 countries. Scientific Reports 11(1), 3052.

Societal concern with the welfare of egg laying hens housed in conventional cages is fostering a transition towards cage-free systems in many countries. However, although cage-free facilities enable hens to move freely and express natural...

Lasky, M., Campbell, J., Osborne, J. A. et al. 2021. Increasing browse and social complexity can improve zoo elephant welfare. Zoo Biology 40(1), 9–19.

While recent work has assessed how environmental and managerial changes influence elephant welfare across multiple zoos, few studies have addressed the effects of management changes within a single institution. In this paper, we examine how...

Adler, C., Schmithausen, A. J., Trimborn, M. et al. 2021. Effects of a partially perforated flooring system on ammonia emissions in broiler housing—Conflict of objectives between animal welfare and environment? Animals 11(3), 707.

A partially (50%) perforated flooring system showed positive effects on health- and behavior-based welfare indicators without affecting production performance. Ammonia (NH3) is the most common air pollutant in poultry production, with effects on animal welfare...

Sans, E. C. O., Tuyttens, F. A.M., Taconeli, C. A. et al. 2021. Welfare of broiler chickens reared under two different types of housing. Animal Welfare 30(3), 341-353.

We compared closed- and open-sided industrial houses with respect to the welfare of broiler chickens in southern Brazil. Ten flocks from each design were evaluated and measures divided into the following categories: i) bird health...

Glaeser, S. S., Shepherdson, D., Lewis, K. et al. 2021. Supporting zoo Asian elephant (Elephas maximus) welfare and herd dynamics with a more complex and expanded habitat. Animals 11(9), 2566.

Ensuring good health and welfare is an increasingly important consideration for conservation of endangered species, whether free-ranging or managed to varying degrees under human care. The welfare-based design of a new habitat for Asian elephants...

Hörner, F., Oerke, A.-K., Müller, D. W. H. et al. 2021. Monitoring behaviour in African elephants during introduction into a new group: Differences between related and unrelated animals. Animals 11(10), 2990.

The introduction of elephants into new groups is necessary for breeding programmes. However, behavioural studies on the reactions of these animals at first encounters are missing. In the present study, female African elephants (Loxodonta africana)...