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. 
James, C., Nicholls, A., Freeman, M. et al. 2021. Should zoo foods be chopped: Macaws for consideration. Journal of Zoo and Aquarium Research, 9(4), 200-207.

Globally, many zoological collections provide their animals with diets that are chopped into small chunks, yet there is limited empirical research to measure the benefits of this practice. Preparing chopped diets takes considerable amounts of...

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...

Hewitt, L., Small, A. 2021. Welfare of farmed crocodilians: Identification of potential animal-based measures using elicitation of expert opinion. Animals 11(12), 3450.

Animal-based measures are the measure of choice in animal welfare assessment protocols as they can often be applied completely independently to the housing or production system employed. Although there has been a small body of...

Watson, P. 2021. Management of naked mole rats (Heterocephalus glaber) at Chester Zoo. RATEL (Journal of the Association of British and Irish Wild Animal Keepers) 48(3), 24-26.

This species first arrived at Chester Zoo in June 2014 when a colony of 27 animals was imported from Dresden Zoo, Germany. As with any new species our journey with naked mole rats has not...

Mellor, E. L., McDonald Kinkaid, H. K., Mendl, M. T. et al. 2021. Nature calls: Intelligence and natural foraging style predict poor welfare in captive parrots. Proceedings of the Royal Society B: Biological Sciences 288(1960), 20211952

Understanding why some species thrive in captivity, while others struggle to adjust, can suggest new ways to improve animal care. Approximately half of all Psittaciformes, a highly threatened order, live in zoos, breeding centres and...

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...

Edes, A. N., Baskir, E., Bauman, K. L. et al. 2021. Effects of crowd size, composition, and noise level on pool use in a mixed-species penguin colony. Animal Behavior and Cognition 8(4), 507–520.

Studies on how visitors affect penguins in human care report a mixture of negative, neutral, and positive impacts on behavior and physiology. Swimming is a highly motivated behavior that may promote positive welfare in penguins...

Fernandez, E. J., Myers, M., Hawkes, N. C. 2021. The effects of live feeding on swimming activity and exhibit use in zoo Humboldt penguins (Spheniscus humboldti). Journal of Zoological and Botanical Gardens 2(1), 88–100.

Penguins are considered among the most popular animals for zoo and aquarium visitors to observe. Swimming is considered a desirable activity, both for the visitor experience and the welfare of the penguins. However, little is...

Ramont, M., Leahy, M., Cronin, K. A. 2021. Domestic animal welfare at the zoo: The impact of an animal visitor interaction program on chickens. Animal Behavior and Cognition 8(1), 1–14.

Many modern zoos strive to create connections between guests and animals through animal visitor interaction (AVI) programs. However, there has been relatively little research into the effect of AVI programs on the welfare of program...

Riley, A., Terry, M., Freeman, H. et al. 2021. Evaluating the effect of visitor presence on Nile crocodile (Crocodylus niloticus) behavior. Journal of Zoological and Botanical Gardens 2(1), 115–129.

Visitor presence has been shown to affect the behavior of animals in zoos. However, studies to date have not included a wide range of taxonomic groupings, and thus, the effect is poorly understood for many...

Wascher, C. A. F., Baur, N., Hengl, M. et al. 2021. Behavioral responses of captive corvids to the presence of visitors. Animal Behavior and Cognition 8(4), 481–492.

Behavioral responses of captive animals to the presence of visitors in zoos and wildlife parks can be interpreted as signs of negative (disturbance), neutral or positive (enrichment) welfare. In the present study, we investigated behavioral...

Muvhali, P. T., Bonato, M., Engelbrecht, A. et al. 2020. Extensive human presence and regular gentle handling improve growth, survival and immune competence in ostrich chicks. Journal of Applied Animal Welfare Science 23(1), 95-107.

A total of 416 day-old ostrich chicks were randomly allocated to one of the three different husbandry practices for 3 months after hatch; HP1 (extensive human presence with gentle human voice, visual and gentle physical...

Andreasen, S. N., Sandøe, P., Waiblinger, S. et al. 2020. Negative attitudes of Danish dairy farmers to their livestock correlates negatively with animal welfare. Animal Welfare 29(1), 89-98.

Positive stockperson attitudes to his or her animals is associated with a positive behavioural response in the animals and in other indicators assumed to reflect a high level of welfare as well as increased productivity...

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)...

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...

Boers, K. L., Allender, M. C., Novak, L. J. et al. 2020. Assessment of hematologic and corticosterone response in free-living eastern box turtles (Terrapene carolina carolina) at capture and after handling. Zoo Biology 39(1), 13-22.

Hematology is a common tool for wildlife health assessments. Manual leukocyte counts are required in reptiles, however, disagreement between quantification methods has been observed in some chelonians. This study determined agreement between two methods of...

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...