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. 
Li, G., Li, B., Shi, Z. et al. 2020. Diurnal rhythms of group-housed layer pullets with free choices between light and dim environments. Canadian Journal of Animal Science 100(1), 37-46.

Chickens under appropriate light–dark programs can develop diurnal rhythms. However, actual needs of layer pullets for the light and dark environments are not fully understood. This study was to investigate the diurnal rhythms of pullets...

Thøfner, I., Hougen, H. P., Villa, C. et al. 2020. Pathological characterization of keel bone fractures in laying hens does not support external trauma as the underlying cause. PLOS ONE 15(3), e0229735.

Keel bone fractures in laying hens have been described with increasing prevalence from several countries over the last twenty years and are considered one of the greatest welfare problems to the layer industry. In Denmark...

Armstrong, E. A., Rufener, C., Toscano, M. J. et al. 2020. Keel bone fractures induce a depressive-like state in laying hens. Scientific Reports 10(1), 3007.

In commercial flocks of laying hens, keel bone fractures (KBFs) are prevalent and associated with behavioural indicators of pain. However, whether their impact is severe enough to induce a depressive-like state of chronic stress is...

Ross, S. R., Leinwand, J. G. 2020. A review of research in primate sanctuaries. Biology Letters 16(4), 1620200033.

While non-human primate studies have long been conducted in laboratories, and more recently at zoological parks, sanctuaries are increasingly considered a viable setting for research. Accredited sanctuaries in non-range countries house thousands of primates formerly...

Morrin, Y. 2020. No bullies allowed! Co-operative feeding as a means to enhance the welfare of 'sub-ordinates'. RATEL (Journal of the Association of British and Irish Wild Animal Keepers) 47(1), 18-19.

This article describes a protocol for training capuchins for co-operative feeding. Three months after beginning the training, the two dominant individuals consistently stay stationed, calmly focused, and the keeper is able to hand the subordinate...

Ebel, S. J., Kopp, K. S., Liebal, K. 2020. Object preferences in captive Sumatran orang-utans (Pongo abelii). Behavioural Processes 170, 103993.

While preferences for perceptual features of objects are well studied in humans, little is known about this trait in other great apes. We therefore presented captive Sumatran orang-utans (Pongo abelii) with objects that differed in...

Reese, L., Baumgartner, K., von Fersen, L. et al. 2020. Feather corticosterone measurements of greater flamingos living under different forms of flight restraint. Animals 10(4), 605.

Deflighting zoo birds is a practice that receives increasing criticism due to its presumed incompatibility with animal welfare. To our knowledge, this is the first approach to address this problem in a scientific way. To...

Trocino, A., White, P., Bordignon, F. et al. 2020. Effect of feed restriction on the behaviour and welfare of broiler chickens. Animals 10(5), 830.

Under intensive rearing conditions, the welfare of broiler chickens may be at risk depending on genotype and sex, due to their different growth rates. The practice of quantitative feed restriction may also impact on welfare...

Spindler, B., Weseloh, T., Eßer, C. et al. 2020. The effects of UV-A light provided in addition to standard lighting on plumage condition in laying hens. Animals 10(6), 1106.

Natural light with ultraviolet spectrum (UV) influences the birds´ perception, the reflectivity of their plumage and affects bird behavior. Therefore, in Germany, laying hens kept in barns should be provided with daylight inlets. Nevertheless, lighting...

Monckton, V., van Staaveren, N., Harlander-Matauschek, A. 2020. Broiler chicks’ motivation for different wood beddings and amounts of soiling. Animals 10(6), 1039.

In the wild, excreta soiled surroundings can attract predators and spread disease. Yet, farmers rear broiler chicks in large barns with stocking densities that prevent excreta segregation. To measure chicks’ motivation to access unsoiled bedding...

Tahamtani, F. M., Riber, A. B. 2020. The effect of qualitative feed restriction in broiler breeder pullets on fear and motivation to explore, Applied Animal Behaviour Science 228, 105009.

Restrictively fed broiler breeders are known to have increased motivation to explore and reduced fearfulness because hunger increases the motivation to search for and to acquire food, forcing the birds to face and engage with...

Soliman, F. N. K., El-Sabrout, K. 2020. Light wavelengths/colors: Future prospects for broiler behavior and production. Journal of Veterinary Behavior 36, 34-39.

Assessing animal welfare is necessary from animal behavior and product quality/quantity perspectives. Birds have a unique visual system and see in the range of 315-750 nm. Most of their behavior is mediated by vision. Lighting...

Brown, M. E., Torkelson, M. R., Olsen, G. H. et al. 2020. Comparison of fecal glucocorticoid metabolite concentrations in hand‐ versus parent‐reared whooping cranes (Grus americana). Zoo Biology 39(4), 276–280.

Endangered whooping cranes (Grus americana ) have been produced in captivity for reintroduction programs since the 1980s, using techniques such as artificial insemination, multiple clutching, and captive‐rearing to speed recovery efforts. Chicks are often hand‐reared...

Bari, M. S., Downing, J. A., Dyall, T. R. et al. 2020. Relationships between rearing enrichments, range use, and an environmental stressor for free-range laying hen welfare. Frontiers in Veterinary Science 7, 480.

Enrichments during pullet rearing may improve adaptation and welfare of hens as they move from indoor rearing to a free-range system. Individual variation in outdoor ranging may also affect welfare. This study assessed the effects...

Tahamtani, F. M., Moradi, H., Riber, A. B. 2020. Effect of qualitative feed restriction in broiler breeder pullets on stress and clinical welfare indicators. Frontiers in Veterinary Science 7, 316.

The feed restriction applied during rearing of broiler breeders inflicts chronic hunger, and frustration due to unfulfilled behavioural needs for feeding. To alleviate the welfare problems associated with feed restriction, qualitative feed restriction allows a...

Nordquist, R. E., Zeinstra, E. C., Dougherty, A. et al. 2020. Effects of dark brooder rearing and age on hypothalamic vasotocin and feather corticosterone levels in laying hens. Frontiers in Veterinary Science 7, 19.

Chickens cannot independently thermoregulate at hatch and lack opportunity to behaviorally thermoregulate with a hen in the egg layer industry, thus barns are heated to thermoneutral temperatures. Dark brooders are low-energy-consuming hot plates, which may...

Andrade, B. M.T., Freire-Filho, R., Bezerra, B. 2020. The behaviours of a female blonde capuchin (Sapajus flavius) towards her dead infant. Behaviour 157(14/15), 1231-1238.

Here we describe the behaviour of a female blonde capuchin (Sapajus flavius) towards her dead infant and discuss possible explanations linked to the anecdotal event. We conducted our study in a fragment of Atlantic forest...

Augustin, A. J., Crabbs, M. A., Sour, M. C. et al. 2020. Efficient, effective, reusable, and customizable social housing for chickens in the laboratory. Laboratory Animal Science Professional 8(5) (September/October), 56-58.

The Iowa State University Laboratory Animal Resources Department needed caging specifically designed and purposed to socially house chickens in the laboratory. As indoor housing requests for chickens increased, the need for a dedicated caging system...

Chapa, J. M., Maschat, K., Iwersen, M. et al. 2020. Accelerometer systems as tools for health and welfare assessment in cattle and pigs – A review. Behavioural Processes 181, 104262.

Welfare assessment has traditionally been performed by direct observation by humans, providing information at only selected points in time. Recently, this assessment method has been questioned, as ‘Precision Livestock Farming’ technologies may be able to...

Cloutier Barbour, C., Danforth, M. D., Murphy, H. et al. 2020. Monitoring great ape heart health through innovative electrocardiogram technology: Training methodologies and welfare implications. Zoo Biology 39(6), 443-447.

Assessing and treating cardiovascular disease (or heart disease) is a growing concern for institutions housing great apes, as it is a major cause of mortality in all four taxa managed in human care. As part...

Bessa Ferreira, V. H., De Paiva Fonseca, E., Chagas, Correia Santos Das, A. C. et al. 2020. Personality traits modulate stress responses after enclosure change of captive capuchin monkeys (Sapajus libidinosus). Applied Animal Behaviour Science 232, 105111.

Husbandry procedures may cause behavioral and physiological changes to animals living in captivity. However, an individual’s reaction is not uniform and may be related to different coping strategies. In this study, we analyzed whether and...

Gebhardt-Henrich, S. G., Jordan, A., Toscano, M. J. et al. 2020. The effect of perches and aviary tiers on the mating behaviour of two hybrids of broiler breeders. Applied Animal Behaviour Science 233, 105145.

Broiler breeders are kept for the production of fertile eggs. They face serious welfare problems like aggressive behaviour of the males towards females during mating. Furthermore, broiler breeders are usually kept without perches which are...

Ipema, A. F., Gerrits, W. J. J., Bokkers, E. A. M. et al. 2020. Provisioning of live black soldier fly larvae (Hermetia illucens) benefits broiler activity and leg health in a frequency- and dose-dependent manner. Applied Animal Behaviour Science 230, 105082.

Fast-growing broilers spend most their time inactive and are therefore prone to experience leg problems. Environmental enrichment that facilitates intrinsically motivated behaviours can potentially promote activity and reduce leg problems, thereby improving broiler welfare. A...

Liu, Z., Torrey, S., Newberry, R. C. et al. 2020. Play behaviour reduced by environmental enrichment in fast-growing broiler chickens. Applied Animal Behaviour Science 232, 105098.

The objective of this study was to evaluate effects of environmental enrichment on play behaviour in fast-growing broiler chickens. Chicks (19 of each sex) were randomly assigned to 6 non-enriched (NE) pens and 6 pens...

Meyer, M. M., Johnson, A. K., Bobeck, E. A. 2020. Development and validation of broiler welfare assessment methods for research and on-farm audits. Journal of Applied Animal Welfare Science 23(4), 433-446.

Required auditing of on-farm broiler welfare in the United States has increased; however, a lack of validated tools exists for assessment of enrichment. National Chicken Council (NCC) guidelines were used on a subset of 300...