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...

Majelantle, T. L., Ganswindt, A., Ganswindt, S. B. et al. 2023. Non-invasive quantification of faecal and urine reproductive hormone metabolites in the naked mole-rat (Heterocephalus glaber). Animals 13(19), 3039.

The naked mole-rat (Heterocephalus glaber) occurs in colonies with a distinct dominance hierarchy, including one dominant, breeding female (the queen), 1–3 breeding males, and non-reproductive subordinates of both sexes that are reproductively suppressed while 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...

Hirata, S. 2022. Sky after 30 years: A brief biography of three biomedical research chimpanzees in Japan. Primates 63(2), 105–108.

This article describes the strategies employed by Kumamoto Sanctuary in Japan to integrate 3 retired chimpanzees – who each spent 30 years singly housed in a biomedical facility – with the sanctuary’s other residents.

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...

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...

Chmurska-Gąsowska, M., Sowińska, N., Pałka, S. et al. 2021. Non-invasive measurement of thyroid hormones in domestic rabbits. Animals 11(5), 1194.

Thyroid hormones are essential for metabolism, energy homeostasis and reproduction. Hormones can be measured in various biological source materials: blood, feces, urine, saliva and others. The aim of our study was to verify usefulness of...

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)...

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...

Schodl, K., Wiesauer, L., Winckler, C. et al. 2021. Reduced stocking density and provision of straw in a rack improve pig welfare on commercial fattening farms. Frontiers in Veterinary Science 8, 656211.

The aim of this study was to investigate the impact of reduced stocking density in combination with provision of additional enrichment material on pig welfare on-farm. On three growing-finishing farms in Austria, in total 974...

Ross, S. R., Lake, B. R., Fultz, A. et al. 2021. An evaluation of thermal imaging as a welfare monitoring tool for captive chimpanzees. Primates 62(6), 919-927.

Among the growing list of novel tools with which to assess animal welfare is the use of thermal (infrared) imaging. The technology has already been utilized to identify emotional arousal in several nonhuman primate species...

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...

Jorquera-Chavez, M., Fuentes, S., Dunshea, F. et al. 2020. Remotely sensed imagery for early detection of respiratory disease in pigs: A pilot study. Animals 10(3), 451.

Respiratory diseases are a major problem in the pig industry worldwide. Due to the impact of these diseases, the early identification of infected herds is essential. Computer vision technology, using RGB (red, green and blue)...

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...

Bøgh, N., Agger, P., Omann, C. et al. 2020. New device for noninvasive telemetric monitoring of vital signs in healthy and newly operated piglets. JAALAS 59(1), 90–93.

Measuring vital signs is central to medical practice, but they are difficult to monitor in awake laboratory animals. We examined the feasibility of a noninvasive device [Cortrium C3 device] for telemetric assessment of respiration rate...

Wolf, T. E., Mangwiro, N., Fasina, F. O. et al. 2020. Non-invasive monitoring of adrenocortical function in female domestic pigs using saliva and faeces as sample matrices. PLOS ONE 15(6): e0234971.

Intensive pig management involves in a commercial setting the housing and implementation of certain procedures, such as castration and tail docking, which may be stressful for the animal. Good farming practices include the reduction of...