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. 
Arrazola, A., Mosco, E., Widowski, T. M. et al. 2020. The effect of alternative feeding strategies during rearing on the behaviour of broiler breeder pullets. Applied Animal Behaviour Science 224, 104929.

Broiler breeders are feed-restricted during rearing to avoid the negative consequences of obesity during lay due to their genetic potential for fast growth rate. Feed restriction leads to chronic hunger, frustration and lack of satiety...

Baxter, M., Richmond, A., Lavery, U. et al. 2020. Investigating optimal levels of platform perch provision for windowed broiler housing. Applied Animal Behaviour Science 225, 104967.

Broiler chickens show a preference for platform perches over traditional bar perches. Further information is needed on the optimal provision of these perches in order for them to be successfully installed in commercial systems. This...

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...

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...

Amaya, V., Paterson, M. B. A., Phillips, C. J. C. 2020. Effects of olfactory and auditory enrichment on the behaviour of shelter dogs. Animals 10(4), 581.

Shelter environments are stressful for dogs, as they must cope with many stimuli over which they have little control. This can lead to behavioural changes, negatively affect their welfare and downgrade the human‐animal bond, affecting...

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...

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...

Turcsán, B., Tátrai, K., Petró, E. et al. 2020. Comparison of behavior and genetic structure in populations of family and kenneled beagles. Frontiers in Veterinary Science 7, 183.

In dogs, the social and spatial restriction associated with living in a kennel environment could lead to chronic stress and the development of abnormal behaviors (“kennel-dog syndrome”). However, little is known about how kenneled dogs...

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...

Reinhardt, V. (ed.) 2020. It’s Okay to Cry - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume V. Animal Welfare Institute, Washington, DC.

This is the 5th volume of selected discussions that took place on the electronic Laboratory Animal Refinement & Enrichment Forum between February 2016 and December 2019. The forum was created in October 2002; it allows...

Ibrahim, S. A., Goma, A. A., Alsenosy, A.-w. A. 2020. Springing bottles enrichment toy effect on behaviors and cortisol level of kenneled dogs (Canis lupus familiaris). Alexandria Journal of Veterinary Sciences 66(2), 20-29.

Environmental enrichment used in captive animals with goals of increasing the activity, behavioral diversity, utilization of the environment and reducing abnormal behaviors. The present study was designed to determine the springing feeding bottles toy ameliorative...

Kendrick, J., Stow, R., Ibbotson, N. et al. 2020. A novel welfare and scientific approach to conducting dog metabolism studies allowing dogs to be pair housed. Laboratory Animals 54(6), 588-598.

Metabolism cages are designed to conduct absorption, distribution, metabolism and excretion (ADME) studies, enabling an ‘excretion balance’ scientific objective to be met. Historically, the design of dog metabolism cages has involved single housing. This type...

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...

Buchanan, K. 2020. DIY: Frozen chicken broth treats. Laboratory Animal Science Professional 8(6) (November/December), 37.

This article gives the recipe for making dog treats. These treats are not only refreshing for dogs, but also easy to make. Mix and match dog friendly fruits and veggies to make many treat varieties.

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...

Dorey, N. R., Blandina, A., Udell, M. A. R. 2020. Clicker training does not enhance learning in mixed-breed shelter puppies (Canis familiaris). Journal of Veterinary Behavior 39, 57-63.

Clicker training has been a popular form of training for decades and is used in zoos, aquariums, and shelters. Only a handful of studies have investigated the efficacy of the clicker-training method itself despite its...