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. 
Morello, G. M., Hultgren, J., Capas-Peneda, S. et al. 2020. High laboratory mouse pre-weaning mortality associated with litter overlap, advanced dam age, small and large litters. PLOS ONE 15(8): e0236290.

High and variable pre-weaning mortality is a persistent problem in laboratory mouse breeding. Assuming a modest 15% mortality rate across mouse strains, means that approximately 1 million more pups are produced yearly in the EU...

Bailoo, J. D., Voelkl, B., Varholick, J. et al. 2020. Effects of weaning age and housing conditions on phenotypic differences in mice. Scientific Reports 10, 11684.

Poor reproducibility is considered a serious problem in laboratory animal research, with important scientific, economic, and ethical implications. One possible source of conflicting findings in laboratory animal research are environmental differences between animal facilities combined...

Brown, M. E., Torkelson, M. R., Olsen, G. H. et al. 2020. Comparison of fecal glucocorticoid metabolite concentrations in hand‐ versus parent‐reared whooping cranes (Grus americana). Zoo Biology 39(4), 276–280.

Endangered whooping cranes (Grus americana ) have been produced in captivity for reintroduction programs since the 1980s, using techniques such as artificial insemination, multiple clutching, and captive‐rearing to speed recovery efforts. Chicks are often hand‐reared...

Turner, P. V., Hickman, D. L., van Luijk, J. et al. 2020. Welfare impact of carbon dioxide euthanasia on laboratory mice and rats: A systematic review. Frontiers in Veterinary Science 7, 411.

Background: There has been increased concern about the suitability of CO2 as a method for euthanasia of laboratory mice and rats, including the potential discomfort, pain or distress that animals may experience prior to loss...

Nordquist, R. E., Zeinstra, E. C., Dougherty, A. et al. 2020. Effects of dark brooder rearing and age on hypothalamic vasotocin and feather corticosterone levels in laying hens. Frontiers in Veterinary Science 7, 19.

Chickens cannot independently thermoregulate at hatch and lack opportunity to behaviorally thermoregulate with a hen in the egg layer industry, thus barns are heated to thermoneutral temperatures. Dark brooders are low-energy-consuming hot plates, which may...

Maschat, K., Dolezal, M., Leeb, C. et al. 2020. Duration of confinement and pen-type affect health-related measures of welfare in lactating sows. Animal Welfare 29(3), 339-352.

Temporary crating is considered as a step towards improved welfare in lactating sows. Therefore, the aim of this study was to investigate effects of confinement period (CP) and farrowing pen-type (PT) on health-related measures. Four...

Andrade, B. M.T., Freire-Filho, R., Bezerra, B. 2020. The behaviours of a female blonde capuchin (Sapajus flavius) towards her dead infant. Behaviour 157(14/15), 1231-1238.

Here we describe the behaviour of a female blonde capuchin (Sapajus flavius) towards her dead infant and discuss possible explanations linked to the anecdotal event. We conducted our study in a fragment of Atlantic forest...

Shomer, N. H., Allen-Worthington, K. H., Hickman, D. L. et al. 2020. Review of rodent euthanasia methods. JAALAS 59(3), 242–253.

The optimal choice of euthanasia method for laboratory rodents depends on a number of factors, including the scientific goals of the study, the need to minimize animal pain and/or distress, applicable guidelines and laws, the...

Laferriere, C. A., Pang, D. S. 2020. Review of intraperitoneal injection of sodium pentobarbital as a method of euthanasia in laboratory rodents. JAALAS 59(3), 254–263.

Euthanasia is one of the most commonly performed procedures in biomedical research, involving tens of millions of animals in North America and Europe every year. The use of sodium pentobarbital, injected intraperitoneally, for killing rodents...

Laferriere, C. A., Leung, V. S., Pang, D. S. 2020. Evaluating intrahepatic and intraperitoneal sodium pentobarbital or ethanol for mouse euthanasia. JAALAS 59(3), 264–268.

Intraperitoneal (IP) injection of sodium pentobarbital (PB) is an accepted method of euthanasia for mice. However, this method has important drawbacks, including the potential for pain or misinjection. The objective of this prospective, randomized, blinded...

Galex, I. A., Gallant, C. M., D'Avignon, N. et al. 2020. Evaluation of effective and practical euthanasia methods for larval African clawed frogs (Xenopus laevis). JAALAS 59(3), 269–274.

Larval, or tadpole-stage Xenopus laevis frogs are a popular research model for developmental biology and disease studies. Existing euthanasia guidance documents offer recommendations for both eggs and adult stages, yet do not specifically address the...

Ceballos, M. C., Góis, K. C. R., Parsons, T. D. 2020. The opening of a hinged farrowing crate improves lactating sows’ welfare. Applied Animal Behaviour Science 230, 105068.

Concerns about the welfare of lactating sows housed in farrowing crates have emerged because crates physically restrict the sows and possibly compromise their behavior and comfort. The aim of this study was to identify how...

Freitas-de-Melo, A., Ungerfeld, R. 2020. The sex of the offspring affects the lamb and ewe responses to abrupt weaning. Applied Animal Behaviour Science 229, 105008.

Female lambs have a stronger attachment with their mothers and show a greater susceptibility to stressors than male lambs. Male lambs grow faster than female lambs do, achieving a greater nutritional independence from their mothers...

Loftus, L., Bell, G., Padmore, E. et al. 2020. The effect of two different farrowing systems on sow behaviour, and piglet behaviour, mortality and growth. Applied Animal Behaviour Science 232, 105102.

Farrowing crates have traditionally been used to reduce occurrence of piglet mortality as a result of sow crushing. However the utilisation of traditional farrowing crates has been suggested to contribute to negative welfare for both...

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...

Rault, J.-L., Lai, A., Hemsworth, L. et al. 2020. Wireless ‘under the skull’ epidural EEG and behavior in piglets during nitrous oxide or carbon dioxide gas euthanasia. Physiology & Behavior 227, 113142.

Consciousness is central to animal welfare concerns. Its assessment is most often conducted based on behavior, with a poor understanding of the correspondence between behavior and the neurobiological processes that underlie the subjective experience of...

Arruda, A. G., Beyene, T. J., Kieffer, J. et al. 2020. A systematic literature review on depopulation methods for swine. Animals 10(11), 2161.

Swine mass depopulation refers to the destruction of large numbers of pigs and may include not only animals affected with a disease but also healthy pigs in a facility or surrounding areas. Emerging applications of...

Cohen, S., Kwok, M., Huang, J. 2020. Humane euthanasia of guinea pigs (Cavia porcellus) with a penetrating spring-loaded captive bolt. Animals 10(8), 1356.

Guinea pigs (Cavia porcellus) have been used in research since the 19th century to collect data due to their physiological similarities to humans. Today, animals perform a vital role in experiments and concerns for laboratory...

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...

Kulkarni, S., Hickman, D. 2020. Isoflurane and carbon dioxide elicit similar behavioral responses in rats. Animals 10(8), 1431.

Euthanasia in rodents is an ongoing topic of debate due to concerns regarding the aversive nature of gases with anesthetic properties such as carbon dioxide (CO2) and isoflurane. The aim of this study was to...

Pedrazzani, A. S., Quintiliano, M. H., Bolfe, F. et al. 2020. Tilapia on-farm welfare assessment protocol for semi-intensive production systems. Frontiers in Veterinary Science 7, 606388.

The aim of this study was to develop and test a tilapia on-farm welfare assessment protocol, based on Brazilian semi-intensive production systems. The study included two mains steps: the elaboration of tilapia welfare protocol and...

Atkinson, S., Algers, B., Pallisera, J. et al. 2020. Animal welfare and meat quality assessment in gas stunning during commercial slaughter of pigs using hypercapnic-hypoxia (20% CO2 2% O2) compared to acute hypercapnia (90% CO2 in Air). Animals 10(12), 2440.

This study assessed aversion, stunning effectiveness, and product quality of nitrogen and carbon dioxide (CO2) mixtures used for stunning pigs. A total of 1852 slaughter pigs divided into two similar batches was assessed during routine...

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...

Zobel, G., Proudfoot, K., Cave, V. et al. 2020. The use of hides during and after calving in New Zealand dairy cows. Animals 10(12), 2255.

Isolation during calving is a common dairy cow behavior, however it has not been examined in large outdoor group settings. The provision of “hides” was monitored for its impact on calving location and cow–calf behavior...

Lindahl, C., Sindhøj, E., Brattlund Hellgren, R. et al. 2020. Responses of pigs to stunning with nitrogen filled high-expansion foam. Animals 10(12), 2210.

Nitrogen gas (N2) delivered in high expansion foam in a closed container could be a feasible method for humanely stunning pigs. This study aimed to evaluate potential aversion in pigs to the N2 foam method...