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. 
Wotton, S., Grist, A., O’Callaghan, M. et al. 2021. Head-only stunning of turkeys Part 2: Subjective and objective assessment of the application of AC and DC waveforms. Animals 11(2), 286.

Electrical stunning is likely to remain an important stunning method for turkeys at slaughter. The purpose of this study is to understand the application of various waveforms of alternating current (AC) and pulsed direct currents...

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...

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...

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)...

Kolarevic, J., Calduch-Giner, J., Espmark, Å. M. et al. 2021. A novel miniaturized biosensor for monitoring Atlantic salmon swimming activity and respiratory frequency. Animals 11(8), 2403.

The advanced development of sensor technologies has led to the emergence of fish biosensors that are currently used for research and commercial purposes. AEFishBIT is a miniaturized biosensor attached to fish operculum that measures physical...

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...

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...

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...

Nash, R., Johnston, H., Robbins, A. et al. 2021. The effect of enrichment filling and engagement time on regurgitation and reingestion behaviour in three zoo-housed orangutans. Journal of Zoological and Botanical Gardens 2(1), 10–20.

Regurgitation and reingestion (R/R) is a prevalent, abnormal behaviour observed in captive great apes. R/R may be related to animal welfare and while less R/R appears to occur when apes are provided with browse and...

Anderson, J., Kaplan-Stein, S., Adolph, S. et al. 2020. Assessment of non-contact infrared thermometer measurement sites in birds. Journal of Applied Animal Welfare Science 23(2), 131-139.

The standard method of obtaining body temperature in a bird can be a stressful event, making routine evaluations challenging. Twenty-eight privately owned birds in good health were enrolled in the study to compare digital and...

Fangmeier, M. L., Burns, A. L., Melfi, V. A. et al. 2020. Foraging enrichment alleviates oral repetitive behaviors in captive red-tailed black cockatoos (Calyptorhynchus banksii). Zoo Biology 39(1), 3-12.

The relationship between inadequate foraging opportunities and the expression of oral repetitive behaviors has been well documented in many production animal species. However, this relationship has been less-well examined in zoo-housed animals, particularly avian species...

Fijn, L., van der Staay, F., Goerlich-Jansson, V. et al. 2020. Importance of basic research on the causes of feather pecking in relation to welfare. Animals 10(2), 213.

Feather pecking is a prominent issue in the commercial egg industry, associated with economic losses and welfare problems. A non-systematic literature search suggests that studies on feather pecking are predominantly concerned with applied research goals...

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...

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...

Guijarro, A., Mauri, S., Aviles, C. et al. 2020. Effects of two CO2 stunning methods on the efficacy of stunning and blood stress indicators of turkeys under commercial processing conditions. Journal of Applied Animal Welfare Science 23(2), 231-243.

The effect of CO2 gas-stunning methods (G1: 30% CO2 15 sec, 55% CO2 40 sec, 70% CO2 45 sec; G2: 30% CO2 15 sec, 80% CO2 85 sec) on the efficacy of stunning, blood stress...

Byrnes, E. E., Lear, K. O., Morgan, D. L. et al. 2020. Respirometer in a box: Development and use of a portable field respirometer for estimating oxygen consumption of large‐bodied fishes. Journal of Fish Biology 96(4), 1045-1050.

Respirometry has become the standard method for measuring the metabolic rate of fishes. Traditionally, respirometry has required the fish to be kept in captivity and tested under controlled conditions; however, many species do not readily...

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...

Michaels, C. J., Gini, B. F., Clifforde, L. 2020. A persistent abnormal repetitive behaviour in a false water cobra (Hydrodynastes gigas). Animal Welfare 29(4), 371-378.

Stereotypies (a subset of Abnormal Repetitive Behaviour [ARB]) are characterised by an unchanging pattern of behaviour and in captive animals can be associated with poor welfare. Although well known in certain taxa, little is known...

Acharya, R., Rault, J.-L. 2020. Risk factors for feather-damaging behavior in companion parrots: A social media study. Journal of Veterinary Behavior 40, 43-49.

Studies on the etiology of behavioral problems often involve interference in the animal's routine or reliance on owners' self-reports like surveys. Gathering data from videos posted on social media, a technique coined ‘video mining’, offers...

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...

Natusch, D. J. D., Aust, P. W., Khadiejah, S. et al. 2020. Behavioral and corticosterone responses to carbon dioxide exposure in reptiles. PLOS ONE 15(10), e0240176.

The use of carbon dioxide (CO2) exposure as a means of animal euthanasia has received considerable attention in mammals and birds but remains virtually untested in reptiles. We measured the behavioral responses of four squamate...

Gent, T. C., Gebhardt-Henrich, S., Schild, S.-L. A. et al. 2020. Evaluation of poultry stunning with low atmospheric pressure, carbon dioxide or nitrogen using a single aversion testing paradigm. Animals 10(8), 1308.

Low atmospheric pressure stunning (LAPS) has been suggested for use in poultry under 4 kg in the abattoir as a more humane alternative to carbon dioxide (CO2). However, there are currently no studies offering a...

Jung, L., Brenninkmeyer, C., Niebuhr, K. et al. 2020. Husbandry conditions and welfare outcomes in organic egg production in eight European countries. Animals 10(11), 2102.

In the European research project HealthyHens, welfare indicators as well as husbandry and management conditions were recorded in 107 organic laying hen farms in eight countries. Farms were visited at peak and end of lay...

Schreiter, R., Damme, K., Freick, M. 2020. Edible environmental enrichments in littered housing systems: Do their effects on integument condition differ between commercial laying hen strains? Animals 10(12), 2434.

The aim of this study was to investigate the effect of additional enrichment materials (EMs; pecking stones and alfalfa bales) on the occurrence of plumage damage, skin injuries, and toe injuries, with an emphasis on...

Wotton, S., Grist, A., O’Callaghan, M. et al. 2020. Head-only stunning of turkeys Part 1: The minimum voltage necessary to break down the inherent high resistance. Animals 10(12), 2427.

Pre-slaughter stunning is required for humane slaughter. For turkeys, head-only electrical stunning is most often used by small scale producers. To ensure immediate and effective stunning, the impedance (resistance) of the tissue of the head...