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. 
Gebhardt-Henrich, S. G., Stratmann, A., Stamp Dawkins, M. 2021. Groups and individuals: Optical flow patterns of broiler chicken flocks are correlated with the behavior of individual birds. Animals 11(2), 568.

Group level measures of welfare flocks have been criticized on the grounds that they give only average measures and overlook the welfare of individual animals. However, we here show that the group-level optical flow patterns...

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...

Iyasere, O. S., Bateson, M., Beard, A. P. et al. 2021. Provision of additional cup drinkers mildly alleviated moderate heat stress conditions in broiler chickens. Journal of Applied Animal Welfare Science 24(2), 188-199.

Sixty-four broilers of a commercial strain in a 2 × 2 factorial design with two environmental conditions: normal (N; 20°C, 50% RH) or MHS (30°C, 70% RH for 6 h/day for 3 consecutive days), and...

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...

Stevens, A., Doneley, R., Cogny, A. et al. 2021. The effects of environmental enrichment on the behaviour of cockatiels (Nymphicus hollandicus) in aviaries. Applied Animal Behaviour Science 235, 105154.

Most research to enrich the environment of psittacines in captivity has focused on foraging. Little is known about the importance of bathing substrates for enrichment of their environment, despite this being a natural behaviour that...

Tahamtani, F. M., Herskin, M. S., Foldager, L. et al. 2021. Assessment of mobility and pain in broiler chickens with identifiable gait defects. Applied Animal Behaviour Science 234, 105183.

Gait defects, assessed as gait score (GS), is a common welfare problem in broiler chicken production. The aim of this study was to examine whether birds with GS2 experience pain and poor locomotor ability compared...

Coleman, K., Shapiro, S. J. (Eds.). 2021. Behavioral Biology of Laboratory Animals (1st ed). CRC Press, Boca Raton, FL.

This 30-chapter volume informs students and professionals about the behavioral biology of animals commonly housed in laboratory and other captive settings. Each species evolved under specific environmental conditions, resulting in unique behavioral patterns, many of...

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...

Phillips, H. N., Heins, B. J. 2021. Effects of outdoor stocking density on growth, feather damage and behavior of slow-growing free-range broilers. Animals 11(3), 688.

Access to pasture is a main benefit of free-range broiler housing systems, yet the level of outdoor stocking density on broiler animal welfare remains unsettled. The growth, feather damage, pasture ranging and behaviors were assessed...

Wichman, A., De Groot, R., Håstad, O. et al. 2021. Influence of different light spectrums on behaviour and welfare in laying hens. Animals 11(4), 924.

Artificial commercial lighting used in animal production facilities can have negative influences on visual abilities, behaviour and welfare of domestic fowl. This study examined the effects of natural-derived light spectrums on behaviour, production and welfare...

Sandilands, V., Baker, L., Donbavand, J. et al. 2021. Effects of different scratch mat designs on hen behaviour and eggs laid in enriched cages. Animals 11(6), 1544.

Laying hens in the UK and EU must be provided with litter for pecking and scratching. In enriched cages, this is commonly provided by dispensing layer’s feed onto a scratch mat. Mats vary in design...

Malchow, J., Schrader, L. 2021. Effects of an elevated platform on welfare aspects in male conventional broilers and dual-purpose chickens. Frontiers in Veterinary Science 8, 660602.

To avoid killing day-old male chicks, one possibility is to keep dual-purpose chicken strains. Here, the hens were kept for egg production, and the roosters were kept for meat production. Both sexes had moderate performances...

Kittelsen, K. E., Gretarsson, P., Jensen, P. et al. 2021. Keel bone fractures are more prevalent in White Leghorn hens than in Red Jungle fowl hens—A pilot study. PLOS ONE 16(7), e0255234.

Fractures and deviations to the keel bone are common in commercial laying hens, with reported variations in occurrence across strains and breeds. The aetiology is not fully understood, however, modern genetics and selection for efficient...

Norman, K. I., Weeks, C. A., Tarlton, J. F. 2021. Rearing experience with ramps improves specific learning and behaviour and welfare on a commercial laying farm. Scientific Reports 11(1), 8860.

To access resources in commercial laying houses hens must move between levels with agility to avoid injury. This study considered whether providing ramps during rear improved the ability of birds to transition between levels. Twelve...

Diarra, S., Lameta, S., Amosa, F. et al. 2021. Alternative bedding materials for poultry: Availability, efficacy, and major constraints. Frontiers in Veterinary Science 8, 669504.

The increasing demand of wood shavings (WS) and sawdust (SD) by other industries and growing concerns of potential chemical contaminants from wood products have amplified research interest in alternative bedding materials for commercial poultry. Several...

Campbell, D. L. M., Whitten, J. M., Slater, E. et al. 2021. Rearing enrichments differentially modified hen personality traits and reduced prediction of range use. Animal Behaviour 179, 97-109.

Domestic fowl have been demonstrated to individually differ in personality, dictating reactions to environmental stimuli. Free-range chickens, Gallus gallus domesticus, show individual range use variation, which may be related to personality differences. Enrichment can also...

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...

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...

Schwarzer, A., Plattner, C., Bergmann, S. et al. 2021. Feather pecking in non-beak-trimmed and beak-trimmed laying hens on commercial farms with aviaries. Animals 11(11), 3085.

Severe feather pecking (SFP) is a major animal welfare problem in layers. It results in pain and injuries in the affected animal. It was the aim of this study to gain insight into the actual...

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...

Miglioli, A., da Silva Vasconcellos, A. 2021. Can behavioural management improve behaviour and reproduction in captive blue-and-yellow macaws (Ara ararauna)? Applied Animal Behaviour Science 241, 105386.

Environments that do not provide animals with appropriate stimuli may affect their welfare and reproduction, for example by precluding them from exhibiting their full behavioural repertoire. In this study, we sought to evaluate the effectiveness...

de Jong, I. C., Blaauw, X. E., van der Eijk, J. E. J. et al. 2021. Providing environmental enrichments affects activity and performance, but not leg health in fast- and slower-growing broiler chickens. Applied Animal Behaviour Science 241, 105375.

Effects of environmental enrichment on activity, behaviour, walking ability, contact dermatitis and performance were investigated in fast- and slower-growing broiler chickens. A total of 840 day-old male broilers, 420 of a fast-growing strain (Ross 308)...

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...