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. 
Evans, L., Brooks, G. C., Anderson, M. G. et al. 2023. Environmental complexity and reduced stocking density promote positive behavioral outcomes in broiler chickens. Animals 13(13), 2074.

The objective was to evaluate the impacts of a complex environment and stocking density on Ross 708 broiler chicken behaviors. Eight pens contained either high complexity (HC) or low complexity (LC) environments, and high (HD)...

Andersen, I. L., Ocepek, M., Thingnes, S. L. et al. 2023. Welfare and performance of finishing pigs on commercial farms: Associations with group size, floor space per pig and feed type. Applied Animal Behaviour Science 265, 105979.

Based on data from a field survey of 85 Norwegian farms, we aimed to investigate associations of group size, floor space per pig and type of feed with selected welfare- and performance indicators in finishing...

Contreras-Jodar, A., Escribano, D., Cerón, J. J. et al. 2023. Reducing stocking densities and using cooling systems for more adapted pigs to high temperatures when reared in intensive conditions. Animals 13(15), 2424.

This study is aimed at evaluating the effect of reducing stocking density and using cooling systems to mitigate the negative effects of high temperatures in growing pigs (females and castrated males) reared in intensive conditions...

Escribano, D., Contreras-Jodar, A., López-Arjona, M. et al. 2023. Changes in cortisol and cortisone in hair of pigs reared under heat stress conditions. Frontiers in Veterinary Science 10.

Heat stress accounts for millions of dollars in losses for swine producers worldwide. The aim of the present study was to determine and evaluate cortisol and cortisone in hair as indicators of thermal stress in...

Turcu, M.-C., Paștiu, A. I., Bel, L.-V. et al. 2023. Minimally invasive sampling methods for molecular sexing of wild and companion birds. Animals 13(21), 3417.

Birds are highly social and must be paired in order to increase their welfare. Most bird species are monomorphic; therefore, molecular sexing helps provide appropriate welfare for birds. Moreover, early sex determination can be of...

Mocz, F., Michel, V., Janvrot, M. et al. 2022. Positive effects of elevated platforms and straw bales on the welfare of fast-growing broiler chickens reared at two different stocking densities. Animals 12(5), 542.

In conventional rearing systems, fast-growing broiler chickens commonly experience welfare issues, such as contact dermatitis, walking difficulties or a lack of expression of species-specific behaviours. Enriching their environment may be a way to improve their...

O'Malley, C. I., Hubley, R., Tambadou, H. et al. 2022. Refining restraint techniques for research pigs through habituation. Frontiers in Veterinary Science 9, 1016414.

Pigs are common research models and are strong animals that can be difficult to restrain. Improper restraint can put pigs and research personnel at risk for injury and induce stress, which can affect research outcomes...

O’Malley, C. I., Hubley, R., Tambadou, H. et al. 2022. Refining restraint techniques for research pigs through habituation. Frontiers in Veterinary Science 9, 1016414.

Pigs are common research models and are strong animals that can be difficult to restrain. Improper restraint can put pigs and research personnel at risk for injury and induce stress, which can affect research outcomes...

Schwarzer, A., Erhard, M., Schmidt, P. et al. 2022. Effects of stocking rate and environmental enrichment on the ontogeny of pecking behavior of laying hen pullets confined in aviary compartments during the first 4 weeks of life. Animals 12(19), 2639.

The objective of this study was to describe the ontogeny of the severe feather pecking (SFP), gentle feather pecking (GFP), aggressive pecking (AP), and enrichment pecking (EP) of non-beak-trimmed Lohmann Brown (LB)-pullets during the first...

van der Eijk, J. A. J., Gunnink, H., Melis, M. et al. 2022. Reducing stocking density benefits behaviour of fast- and slower-growing broilers. Applied Animal Behaviour Science 257, 105754.

The broiler industry has come under sustained pressure from welfare organizations to improve broiler welfare. Breed and stocking density are important factors for broiler welfare and are often specified as criteria for higher welfare systems...

Wang, M., Youssef, Al., Larsen, M. et al. 2021. Contactless video-based heart rate monitoring of a resting and an anesthetized pig. Animals 11(2), 442.

Heart rate (HR) is a vital bio-signal that is relatively easy to monitor with contact sensors and is related to a living organism’s state of health, stress and well-being. The objective of this study was...

Wiechers, D.-H., Brunner, S., Herbrandt, S. et al. 2021. Analysis of hair cortisol as an indicator of chronic stress in pigs in two different farrowing systems. Frontiers in Veterinary Science 8, 605078.

Confinement to farrowing crates is known to prevent sows from performing natural behavior, impairing animal welfare and possibly causing chronic stress. Hair cortisol analyses are increasingly used to detect chronic stress in animals. In the...

Stracke, J., Volkmann, N., May, F. et al. 2021. Walking on tiptoes: Digital pads deserve increased attention when scoring footpad dermatitis as an animal welfare indicator in turkeys. Frontiers in Veterinary Science 7, 613516.

Animal welfare is one of the most challenging issues in modern farm animal husbandry. Animal welfare indicators can be used to monitor welfare on farms or at slaughterhouses, with footpad dermatitis (FPD) being one of...

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...

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...

Prior, H., Holbrook, M. 2021. Strategies to encourage the adoption of social housing during cardiovascular telemetry recordings in non-rodents. Journal of Pharmacological and Toxicological Methods 108, 106959.

The National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) is working with industry to promote social housing during cardiovascular telemetry recordings within non-rodent safety pharmacology and toxicology studies. Following surveys...

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...

Schmid, S. M., Büscher, W., Steinhoff-Wagner, J. 2021. Suitability of different thermometers for measuring body core and skin temperatures in suckling piglets. Animals 11(4), 1004.

Monitoring the temperature of piglets after birth is critical to ensure their well-being. Rectal temperature measurement is time-consuming, requires fixation of the animal and is stressful for piglets. This study aims to evaluate the effectiveness...

Huber, N., Mahr, K., Tóth, Z. et al. 2021. The stressed bird in the hand: Influence of sampling design on the physiological stress response in a free-living songbird. Physiology & Behavior 238, 113488.

Despite the widely used application of standardized capture-handling protocols to collect blood and assess the physiological stress response, the actual sampling design (e.g., timing and the number of blood samples) often differs between studies, and...

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...

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)...

Holdsworth, S. E., Kells, N. J., Chidgey, K. L. et al. 2021. Characterisation of the behavioural effects of a thoracic squeeze in healthy newborn piglets. Animals 11(8), 2465.

Firmly squeezing the chests of newborn foals and calves that are showing abnormal behaviours after birth causes them to enter a less-responsive state, characterised by lying down with eyes closed and no limb movements. Once...

Lagoda, M. E., Boyle, L. A., Marchewka, J. et al. 2021. Early detection of locomotion disorders in gilts using a novel visual analogue scale; associations with chronic stress and reproduction. Animals 11(10), 2900.

Locomotion scoring is crucial for the early detection of lameness, which reduces sow welfare and performance. Our objective was to test the effectiveness of a visual analogue scale (VAS) to measure locomotory ability (OVERALL) compared...

Ferrari, P., Ulrici, A., Barbari, M. 2021. Analysis of housing risk factors for the welfare of lean and heavy pigs in a sample of European fattening farms. Animals 11(11), 3221.

Pig welfare is affected by housing conditions, the minimum requirements of which are set up by EU legislation. Animal and non-animal-based measures are useful indicators to investigate housing risk factors for pig welfare. An observational...

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...