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. 
Rørvang, M. V., Blad, M., Lindahl, C. et al. 2024. An added aroma changes the behaviour of domestic pigs in a novel situation aimed for stunning. Applied Animal Behaviour Science 270, 106145.

The currently most widespread stunning method for pigs is high concentration of carbon dioxide (CO2), but this method is under scrutiny due to animal welfare deficits. One alternative method currently under development with potential to...

Valros, A., Norring, M., Ahlqvist, K. et al. 2024. Effects of repeated intramuscular injections on sow behaviour reactions and stress-related saliva biomarkers – A pilot study. Applied Animal Behaviour Science 271, 106173.

Medicating large production animals, such as sows, individually can be challenging, especially when repeated treatments are needed. Intramuscular (i.m.) injections have been shown to be aversive, and an increased reaction could be expected over consecutive...

Kumar, P., Abubakar, A. A., Ahmed, M. A. et al. 2023. Electroencephalogram and physiological responses as affected by slaughter empathy in goats. Animals 13(6), 1100.

Recent advances in emotions and cognitive science make it imperative to assess the emotional stress in goats at the time of slaughter. The present study was envisaged to study the electroencephalogram and physiological responses as...

Söderquist, A., Wallenbeck, A., Lindahl, C. 2023. Social support in a novel situation aimed for stunning and euthanasia of pigs may be increased by familiar pigs—A behavioural study with weaners. Animals 13(3), 481.

The common method of stunning pigs using high concentration carbon dioxide prior to slaughter poses an animal welfare issue, as the gas is aversive. Proof of concept for using nitrogen gas encapsulated in high-expansion foam...

Ferreira, M. F., Fàbrega, E., Pires, I. et al. 2023. Agonic aspiration of blood: Not useful as an animal-based indicator of electrical stunning ineffectiveness in pigs (Sus scrofa domesticus). Animals 13(14), 2292.

Agonic aspiration of blood (AAB) may result from an inadequate exsanguination with accidental trachea severing, that can be favoured by ineffective stunning of pigs (Sus scrofa domesticus). This study aimed to evaluate AAB as an...

Hognestad, B. W., Digranes, N., Opsund, V. G. et al. 2023. CO2 stunning in pigs: Physiological deviations at onset of excitatory behaviour. Animals 13(14), 2387.

Stunning by carbon dioxide (CO2) inhalation is controversial because it is associated with vigorous movements and behaviours which may or may not be conscious reactions. Furthermore, it is unknown whether some behaviours might indicate the...

Kieffer, J. D., Campler, M. R., Cheng, T.-Y. et al. 2022. Evaluation of a water-based medium-expansion foam depopulation method in suckling and finisher pigs. Animals 12(8), 1041.

The threat of foreign animal disease introduction through contaminated animal products, feed ingredients, and wildlife vectors have highlighted the need for additional approved methods for mass depopulation of swine under emergency scenarios, especially methods that...

Zapata Cardona, J., Ceballos, M. C., Tarazona Morales, A. M. et al. 2022. Music modulates emotional responses in growing pigs. Scientific Reports 12(1), 3382.

There is a lack of clarity on whether pigs can emotionally respond to musical stimulation and whether that response is related to music structure. Qualitative Behavioral Assessment (QBA) was used to evaluate effects of 16...

Zhang, J., Yu, L., Yin, G. 2022. Evaluation of behavior and affective state of different-parity sows with strong/weak pupil light reflex. Animals 12(9), 1184.

The stall-housing system is commonly used in the modern swine industry in many countries; however, long-term space restrictions can cause affective and physiological abnormalities in sows. The pupil light reflex (PLR) can reflect the psychological...

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...

Korenyi-Both, J., Vidaurre, J., Held, T. et al. 2022. Description of electroencephalographic data gathered using water-based medium-expansion foam as a depopulation method for nursery pigs. Scientific Reports 12(1), 16798.

The United States’ swine industry is under constant threat of foreign animal diseases, which may emerge without warning due to the globalized transportation networks moving people, animals, and products. Therefore, having disease control and elimination...

Korenyi-Both, J., Vidaurre, J., Held, T. et al. 2022. Description of electroencephalographic data gathered using water-based medium-expansion foam as a depopulation method for nursery pigs. Scientific Reports 12(1), 16798.

The United States’ swine industry is under constant threat of foreign animal diseases, which may emerge without warning due to the globalized transportation networks moving people, animals, and products. Therefore, having disease control and elimination...

Martin, J. E., Baxter, E. M., Clarkson, J. M. et al. 2022. Characterizing candidate decompression rates for hypobaric hypoxic stunning of pigs. Part 1: Reflexive behavior and physiological responses. Frontiers in Veterinary Science 9, 1027878.

Alternatives to carbon dioxide (CO2) stunning for the commercial slaughter of pigs are urgently needed because there is robust evidence that exposing pigs to hypercapnic environments is associated with pain, fear, and distress. Hypobaric hypoxia...

Husheer, J., Luepke, M., Dziallas, P. et al. 2021. Electrocution as an alternative euthanasia method to blunt force trauma to the head followed by exsanguination for non-viable piglets. Acta Veterinaria Scandinavica 62, 67.

On farms, the currently approved and most widely practised method of euthanising non-viable piglets is blunt force trauma to the head followed by exsanguination. However, the use of this method is criticised due to public...

Dalla Costa, F. A., Gibson, T. J., Oliveira, S. E.O. et al. 2021. On-farm culling methods used for pigs. Animal Welfare 30(4), 507-522.

The culling of injured and non-viable pigs (Sus scrofa) (neonate to breeding stock) is a routine and necessary procedure on most farms. Usually, pigs are culled using one of the following methods: blunt-force trauma (manual...

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...

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...

MacLellan, A., Fureix, C., Polanco, A. et al. 2021. Can animals develop depression? An overview and assessment of “depression-like” states. Behaviour 158(14/15), 1303–1353.

Describing certain animal behaviours as 'depression-like' or 'depressive' has become common across several fields of research. These typically involve unusually low activity or unresponsiveness and/or reduced interest in pleasure (anhedonia). While the term 'depression-like' carefully...

Campbell, D. L. M., Lee, C. 2021. A perspective on strategic enrichment for brain development: Is this the key to animal happiness? Frontiers in Veterinary Science 8, 720422.

Livestock animals are sentient beings with cognitive and emotional capacities and their brain development, similar to humans and other animal species, is affected by their surrounding environmental conditions. Current intensive production systems, through the restrictions...

Dalmau, A., Sánchez-Matamoros, A., Molina, J. M. et al. 2021. Intramuscular vs. intradermic needle-free vaccination in piglets: Relevance for animal welfare based on an aversion learning test and vocalizations. Frontiers in Veterinary Science 8, 715260.

The aim of the present study was to compare intramuscular injection with a needle and intradermic needle-free vaccinations against porcine reproductive and respiratory syndrome (PRRS) in piglets at 28 days old by studying behavioral and...

Krugmann, K. L., Mieloch, F. J., Krieter, J. 2021. Can tail and ear postures be suitable to capture the affective state of growing pigs? Journal of Applied Animal Welfare Science 24(4), 411-423.

The present study examined whether tail and ear postures in fattening pigs (n = 228) housed in different environments could be suitable for assessing their affective state. In doing so, it investigated the appearance of...

Baciadonna, L., Briefer, E. F., McElligott, A. G. 2020. Investigation of reward quality-related behaviour as a tool to assess emotions. Applied Animal Behaviour Science 225, 104968.

Animals are likely to appraise events as positive or negative based on their subjective perception, current state and past experiences. We tested the effects of anticipating positive (food anticipation), negative (inaccessible food) and neutral (clicker...

Çavuşoğlu, E., Rault, J.-L., Gates, R. et al. 2020. Behavioral response of weaned pigs during gas euthanasia with CO2, CO2 with butorphanol, or nitrous oxide. Animals 10(5), 787.

The swine industry is often forced to euthanize pigs in the first few weeks of life due to injuries, hernias, or unthriftiness. The majority of pigs are euthanized using carbon dioxide (CO2) gas asphyxiation but...

Camerlink, I., Ursinus, W. W. 2020. Tail postures and tail motion in pigs: A review. Applied Animal Behaviour Science 230, 105079.

Animals’ tail posture and motion play an important role in communication, amongst others. In domestic pigs, the debate around tail docking and tail biting has made the tail an important research topic, and tail-related behaviour...

Ocepek, M., Newberry, R. C., Andersen, I. L. 2020. Which types of rooting material give weaner pigs most pleasure? Applied Animal Behaviour Science 231, 105070.

Provision of rooting material as enrichment for pigs has been primarily oriented towards reducing negative affect (suffering). Information is also needed on the impact of different types of rooting materials in promoting positive affect (pleasure)...