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. 
Anderson, M. G., Campbell, A. M., Crump, A. et al. 2021. Effect of environmental complexity and stocking density on fear and anxiety in broiler chickens. Animals 11(8), 2383.

Barren housing and high stocking densities may contribute to negative affective states in broiler chickens, reducing their welfare. We investigated the effects of environmental complexity and stocking density on broilers’ attention bias (measure of anxiety)...

Travain, T., Valsecchi, P. 2021. Infrared thermography in the study of animals’ emotional responses: A critical review. Animals 11(9), 2510.

Whether animals have emotions was historically a long-lasting question but, today, nobody disputes that they do. However, how to assess them and how to guarantee animals their welfare have become important research topics in the...

Jacobs, L., Melick, S., Freeman, N. et al. 2021. Broiler chicken behavior and activity are affected by novel flooring treatments. Animals 11(10), 2841.

The objective was to determine broiler chicken behavioral differences in response to novel flooring treatments. Broilers (n = 182) were housed in 14 pens (a random subset from a larger-scale study including 42 pens), with...

Diana, A., Salas, M., Pereboom, Z. et al. 2021. A systematic review of the use of technology to monitor welfare in zoo animals: Is there space for improvement? Animals 11(11), 3048.

A top priority of modern zoos is to ensure good animal welfare (AW), thus, efforts towards improving AW monitoring are increasing. Welfare assessments are performed through more traditional approaches by employing direct observations and time-consuming...

Hu, J., Xiong, Y., Gates, R. S. et al. 2021. Perches as cooling devices for reducing heat stress in caged laying hens: A review. Animals 11(11), 3026.

Heat stress is one of the most detrimental environmental challenges affecting the biological process and the related production performance of farm animals, especially in poultry. Commercial laying hens have been bred (selected) for high egg...

Forslind, S., Blokhuis, H. J., Riber, A. B. 2021. Disturbance of resting behaviour of broilers under different environmental conditions. Applied Animal Behaviour Science 242, 105425.

Resting behaviours make up a large part of the daily time budget of broilers. However, in intensive broiler production systems disruptions of resting behaviours occur, where resting individuals get disturbed by active individuals. Such interruptions...

Hausmann, J. C., Krisp, A. R., Mans, C. et al. 2021. Analgesic efficacy of tramadol and morphine in White's tree frogs (Litoria caerulea). JAALAS 60(6), 681-686.

Published data are sparse regarding the recognition of clinically relevant pain and appropriate analgesia in amphibians. The amphibian analgesia literature has primarily focused on nociceptive pathways in a single species, the northern leopard frog (Rana...

Wood, B., Rufener, C., Makagon, M. M. et al. 2021. The utility of scatter feeding as enrichment: Do broiler chickens engage with scatter–fed items? Animals 11(12), 3478.

In recent years, welfare certification companies have encouraged the use of scatter feeding as enrichment material, though there is little scientific evidence to support a scatter feeding program. This study aimed to understand the impact...

Costantino, A., Fabrizio, E., Calvet, S. 2021. The role of climate control in monogastric animal farming: The effects on animal welfare, air emissions, productivity, health, and energy use. Applied Sciences 11(20), 9549.

In the last decades, an engineering process has deeply transformed livestock houses by introducing fine-tuned climate control systems to guarantee adequate indoor climate conditions needed to express the maximum genetic potential of animals and to...

Woody, S. M., Santymire, R. M., Cronin, K. A. 2021. Posture as a non-invasive indicator of arousal in American toads (Anaxyrus americanus). Journal of Zoological and Botanical Gardens 2(1), 1–9.

Animal welfare has become a priority for modern zoos and aquariums. However, amphibians have not yet been the focus of much welfare research, perhaps in part because they do not tend to display many quantifiable...

Reese, L., Ladwig-Wiegard, M., von Fersen, L. et al. 2020. Deflighting zoo birds and its welfare considerations. Animal Welfare 29(1), 69-80.

For over a century, the practice of deflighting has taken place in zoological collections in order to ensure birds remain in open-topped enclosures. Over time, efforts have been made to improve or develop new (surgical)...

Piller, A., Bergmann, S., Schwarzer, A. et al. 2020. Validation of histological and visual scoring systems for foot-pad dermatitis in broiler chickens. Animal Welfare 29(2), 185-196.

In this study, an appropriate visual scoring system for foot-pad dermatitis was validated, considering the histologically measured depth of the inflammation zone and the histopathological grade (no lesion, mild lesion, ulcer). The aim being to...

Yerpes, M., Llonch, P., Manteca, X. 2020. Factors associated with cumulative first-week mortality in broiler chicks. Animals 10(2), 310.

First-week mortality is an important performance index as well as an important welfare indicator. The aim of the present study was to identify internal (individual-dependent) and external (management or environmental) factors that could influence the...

Guinebretière, M., Mika, A., Michel, V. et al. 2020. Effects of management strategies on non-beak-trimmed laying hens in furnished cages that were reared in a non-cage system. Animals 10(3), 399.

Beak trimming in laying hens limits the negative consequences of injurious pecking, but could be prohibited by future regulations. This study assessed a combination of management strategies during the rearing period (objects, perches, music, human...

Sobotik, E. B., Nelson, J. R., Archer, G. S. 2020. How does ultraviolet light affect layer production, fear, and stress. Applied Animal Behaviour Science 223, 104926.

The lighting spectrum used in modern poultry production commonly lacks significant amounts of ultraviolet light; however, poultry can perceive the ultraviolet spectrum unlike humans and little research has been done to investigate the importance of...

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...

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...

Harvey, A., Beausoleil, N., Ramp, D. et al. 2020. A ten-stage protocol for assessing the welfare of individual non-captive wild animals: Free-roaming horses (Equus ferus caballus) as an example. Animals 10(1), 148.

Knowledge of the welfare status of wild animals is vital for informing debates about the ways in which we interact with wild animals and their habitats. Currently, there is no published information about how to...

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...

House, G. M., Sobotik, E. B., Nelson, J. R. et al. 2020. Effects of ultraviolet light supplementation on Pekin duck production, behavior, and welfare. Animals 10(5), 833.

Ducks, like other domestic poultry species, can visualize the ultraviolet (UV) portion of the light spectrum; however, the importance of UV light radiation in artificially lit duck growout facilities remains unknown. The objective of this...

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...