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. 
D’Alessio, R. M., Hanlon, A., O’Driscoll, K. 2023. Comparison of single- and double-spaced feeders with regard to damaging behavior in pigs. Frontiers in Veterinary Science 10, 1073401.

This work compared the behavior and performance of 24 groups of 12 pigs kept in pens with either a DOUBLE [one feed space aligned with the front wall of the pen (WALL), and one immediately...

Pan, L., Nian, H., Zhang, R. et al. 2022. Stereotypic behaviors are associated with physiology and immunity differences in long-term confined sows. Physiology & Behavior 249, 113776.

Pregnant sows in the confined environment have poor welfare and frequently perform stereotypic behaviors. In order to clarify whether highly stereotypic behavior is a sign of increased stress and successfully contributes to coping with or...

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...

Li, S., Hu, H., Huang, J. et al. 2022. Effect of enrichment items on the physiology and behavior of sows in the third trimester of pregnancy. Animals 12(11), 1355.

Modern intensive pig breeding harms animal welfare, which is especially noticeable for pregnant sows kept in confinement stalls. This study aimed to evaluate the effects of enrichment items on the movement and physiological parameters of...

Drexl, V., Dittrich, I., Haase, A. et al. 2022. Tail posture as an early indicator of tail biting - A comparison of animal and pen level in weaner pigs. Applied Animal Behaviour Science 252, 105654.

The occurrence of tail biting is one of the most important animal welfare problems in pig farming and needs to be recognised early to reduce injuries and suffering. The posture of the tail could be...

Henry, M., Jansen, H., del Rocio Amezcua, M. et al. 2021. Tail-biting in pigs: A scoping review. Animals 11(7), 2002.

Tail-biting is globally recognized as a welfare concern for commercial swine production. Substantial research has been undertaken to identify risk factors and intervention methods to decrease and understand this vice. Tail-biting appears to be multifactorial...

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...

Kalies, A., Baumgartner, J., Beyerbach, M. et al. 2021. Interactive rooting towers and behavioural observations as strategies to reduce tail biting on conventional pig fattening farms. Animals 11(11), 3025.

Eight pens (25 pigs/pen; n = 200) provided with an interactive straw-filled rooting tower (experimental group) and five pens (25 pigs/pen; n = 125) with a stationary (fixed) tower without straw (control group) were compared...

Hakansson, F., Bolhuis, J. E., 2021. Tail-biting behaviour pre-weaning: Association between other pig-directed and general behaviour in piglets. Applied Animal Behaviour Science 241, 105385.

Tail biting in pigs is a damaging behaviour and remains an economic and welfare problem in modern pig production. Although tail biting has been extensively investigated, little is known about the behaviour in piglets. 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...

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...

D'Eath, R. B., Foister, S., Jack, M. et al. 2021. Changes in tail posture detected by a 3D machine vision system are associated with injury from damaging behaviours and ill health on commercial pig farms. PLOS ONE 16(10), e0258895.

To establish whether pig tail posture is affected by injuries and ill health, a machine vision system using 3D cameras to measure tail angle was used. Camera data from 1692 pigs in 41 production batches...

Zhang, X., Li, C., Hao, Y. et al. 2020. Effects of different farrowing environments on the behavior of sows and piglets. Animals 10(2), 320.

We investigated the effect of different farrowing systems on the behavior of sows and piglets. In total, 22 hybrid sows (Yorkshire × Landrace) were randomly assigned into three farrowing systems, farrowing crate (FC), free farrowing...

Friedrich, L., Krieter, J., Kemper, N. et al. 2020. Frothy saliva—A novel indicator to assess stereotypies in sows? Applied Animal Behaviour Science 222, 104897.

The present study aimed at introducing a reliable and more feasible indicator to evaluate stereotypies in sows in comparison with the ‘Welfare Quality® animal welfare assessment protocol for sows and piglets’. Therefore, the indicators for...

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...

Chou, J., O’Driscoll, K., Sandercock, D. A. et al. 2020. Can increased dietary fibre level and a single enrichment device reduce the risk of tail biting in undocked growing-finishing pigs in fully slatted systems? PLOS ONE 15(10), e0241619.

This study evaluated the effectiveness of combined dietary and enrichment strategies to manage tail biting in pigs with intact tails in a conventional fully-slatted floor housing system. A 2 × 2 × 2 factorial design...

Ko, H., Chong, Q., Escribano, D. et al. 2020. Pre-weaning socialization and environmental enrichment affect life-long response to regrouping in commercially-reared pigs. Applied Animal Behaviour Science 229, 105044.

Weaning and other regrouping events as routine work in commercial farms cause stress to pigs and compromise their welfare. Several studies found positive outcomes to mitigate weaning stress when piglets were socialized (i.e. co-mingled) or...

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)...

Telkanranta, H., Valros, A. 2020. Pigs with but not without access to pieces of recently harvested wood show reduced pen-mate manipulation after a provision of feed and straw. Applied Animal Behaviour Science 232, 105103.

In barren environments of commercial farms, pig often redirect their rooting and chewing behaviours at other pigs, which can lead to tail biting. When materials such as straw are provided, the quantity is usually too...

Wilder, T., Krieter, J., Kemper, N. et al. 2020. Tail-directed behaviour in pigs – relation to tail posture and tail lesion. Applied Animal Behaviour Science 233, 105151.

Tail-biting in pigs affects the health and welfare of the animals. Different indicators, such as the tail posture, can be used to detect tail-biting at an early stage. The aim of this study was to...

Camerlink, I., Chou, J.-Y., Turner, S. P. 2020. Intra-group lethal gang aggression in domestic pigs (Sus scrofa domesticus). Animals 10(8), 1287.

Intraspecific coalitional aggression is rare among all species, especially within stable social groups. We report here numerous cases of intraspecific lethal gang aggression within stable groups of domestic pigs. The objective was to describe this...

Chou, J.-Y., Sandercock, D. A., D'Eath, R. B. et al. 2020. A High Enrichment replenishment rate reduces damaging behaviors and increases growth rate in undocked pigs kept in fully slatted pens. Frontiers in Veterinary Science 7, 584706.

One of the difficulties in complying with the prohibition of routine tail docking is a lack of effective alternative solutions to prevent tail biting, especially in fully slatted systems. This study compared three slat-compatible enrichment...

Morgan, L., Itin-Shwartz, B., Koren, L. et al. 2019. Physiological and economic benefits of abandoning invasive surgical procedures and enhancing animal welfare in swine production. Scientific Reports 9, 16093.

Food-animal welfare is a major ethical and social concern. Pork is the most consumed meat worldwide, with over a billion pigs slaughtered annually. Most of these pigs routinely undergo painful surgical procedures (surgical castration, tail...