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. 
Ebel, S. J., Kopp, K. S., Liebal, K. 2020. Object preferences in captive Sumatran orang-utans (Pongo abelii). Behavioural Processes 170, 103993.

While preferences for perceptual features of objects are well studied in humans, little is known about this trait in other great apes. We therefore presented captive Sumatran orang-utans (Pongo abelii) with objects that differed in...

da Silva, A., Lima, M. R., Meletti, P. C. et al. 2020. Impact of environmental enrichment and social group size in the aggressiveness and foraging activity of Serrapinnus notomelas. Applied Animal Behaviour Science 224, 104943.

Fish are widely used in scientific research, and many species are bred for ornamental purposes and human consumption. Despite the large number of fish kept in captivity, research on the welfare of these animals has...

Wang, C., Han, Q., Liu, R. et al. 2020. Equipping farrowing pens with straw improves maternal behavior and physiology of Min-Pig hybrid sows. Animals 10(1), 105.

This study investigated the effects of two factors, enriched environment (EE) and different crossbreeds, on the maternal behavior and physiology of Min-pig hybrid sows. The analysis was performed on a total of 72 multiparous sows...

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...

Chou, J.-Y., D’Eath, R. B., Sandercock, D. A. et al. 2020. Enrichment use in finishing pigs and its relationship with damaging behaviours: Comparing three wood species and a rubber floor toy. Applied Animal Behaviour Science 224, 104944.

Environmental enrichment in pig housing is a legal requirement under current EU legislation, but some recommended loose materials may cause obstructions in fully-slatted systems. Wood is an organic material that could be compatible with slatted...

de la Garza, F., Cannon, C. Z. 2020. Piggy see, piggy do: A swine training program enhances animal welfare and research. Laboratory Animal Science Professional 8(2) (March/April), 54-57.

Becton Dickinson (BD) Animal Research Program developed an extensive training and environmental enrichment program to acclimate newly arrived swine to daily husbandry routines. The program seeks to build trust between swine and animal care and...

Luo, L., Jansen, C. A., Bolhuis, J. E. et al. 2020. Early and later life environmental enrichment affect specific antibody responses and blood leukocyte subpopulations in pigs. Physiology & Behavior 217, 112799.

This study addressed the impact of early and later life environmental enrichment, and their combination, on specific antibody responses and peripheral blood leukocyte subpopulations in pigs. Pigs were kept in either barren (B1) or enriched...

Kauselmann, K., Krause, E. T., Glitz, B. et al. 2020. Short-term choice of fattening pigs for additional plant-based materials. Applied Animal Behaviour Science 226, 104975.

A major problem in conventional pig production systems is the occurrence of abnormal behaviours such as tail biting. Tail biting is a multifactorial problem, but it seems that a lack of proper enrichment materials prevents...

Arechavala-Lopez, P., Caballero-Froilán, J. C., Jiménez-García, M. et al. 2020. Enriched environments enhance cognition, exploratory behaviour and brain physiological functions of Sparus aurata. Scientific Reports 10, 11252.

Environmental enrichment is considered as a recommended tool to guarantee or improve the welfare of captive fish. This study demonstrates for the first time that structural environmental enrichment enhances cognition, exploratory behaviour and brain physiological...

Luo, L., Reimert, I., Middelkoop, A. et al. 2020. Effects of early and current environmental enrichment on behavior and growth in pigs. Frontiers in Veterinary Science 7, 268.

Enriched environments are known to beneficially affect the behavior of pigs, as compared with barren pens. The influence of enrichment may, however, depend on pigs' early life housing experiences. The aim of this study was...

Reinhardt, V. (ed.) 2020. It’s Okay to Cry - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume V. Animal Welfare Institute, Washington, DC.

This is the 5th volume of selected discussions that took place on the electronic Laboratory Animal Refinement & Enrichment Forum between February 2016 and December 2019. The forum was created in October 2002; it allows...

Thoré, E. S. J., Brendonck, L., Pinceel, T. 2020. Conspecific density and environmental complexity impact behaviour of turquoise killifish (Nothobranchius furzeri). Fish Biology 97(5), 1448–1461.

Fish models are essential for research in many biological and medical disciplines. With a typical lifespan of only 6 months, the turquoise killifish (Nothobranchius furzeri) was recently established as a time- and cost-efficient model to...

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...

Greene, L. K., Clarke, T. A., Southworth, C. A. et al. 2020. Daily lettuce supplements promote foraging behavior and modify the gut microbiota in captive frugivores. Zoo Biology 39(5), 334-344.

For captive primates, greater provisioning of leafy greens or foliage can promote natural foraging behavior while boosting fiber intake. Recalcitrant fiber, although minimally available to endogenous metabolism, is readily fermented into nutrients by gut microbes...

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., Goold, C. M., Busančić, M. et al. 2020. Maize silage as enrichment material improves the welfare of growing-finishing pigs in environmentally-friendly pens. Applied Animal Behaviour Science 230, 105043.

Provision of enrichment in welfare- and environmentally-friendly pig pens is important for sustainable pig production. The primary aim of the present experiment was to investigate the effects of maize silage as a singular enrichment compared...

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...

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...

Fanning, L., Larsen, H., Taylor, P. S. 2020. A preliminary study investigating the impact of musical concerts on the behavior of captive Fiordland penguins (Eudyptes pachyrhynchus) and collared peccaries (Pecari tajacu). Animals 10(11), 2035.

Captive animal welfare is important for establishments that exhibit species for education, conservation, and research. However, captive animals are often exposed to a number of potential stressors, such as visitors and anthropogenic noise. We aimed...

Mellor, E. L., Cuthill, I. C., Schwitzer, C. et al. 2020. Large lemurs: Ecological, demographic and environmental risk factors for weight gain in captivity. Animals 10(8), 1443.

Excessive body mass, i.e., being overweight or obese, is a health concern associated with issues such as reduced fertility and lifespan. Some lemur species are prone to extreme weight gain in captivity, yet others are...

Villain, A. S., Lanthony, M., Guérin, C. et al. 2020. Manipulable object and human contact: Preference and modulation of emotional states in weaned pigs. Frontiers in Veterinary Science 7, 577433.

Enriching the life of farm animals is a legal obligation in intensive farming conditions in the European Union, though not worldwide. In pigs, manipulable materials are mandatory when no bedding is available. Like manipulable objects...

Marcet-Rius, M., Pageat, P., Bienboire-Frosini, C. et al. 2020. The provision of toys to pigs can improve the human-animal relationship. Porcine Health Management 6, 29.

It is now widely recognised that a positive human-animal relationship is beneficial not only for farm animals’ welfare but also for productivity and the quality of products. A better understanding of animal emotions is an...

Perea Garcia, J. O., Miani, A., Kristian Olsen Alstrup, A. et al. 2020. Orangulas: Effect of scheduled visual enrichment on behavioral and endocrine aspects of a captive orangutan (Pongo pygmaeus): Effect of scheduled visual enrichment on behavioral and endocrine aspects of a captive orangutan. Journal of Zoo and Aquarium Research, 8(1), 67-72.

Captivity may have adverse effects on captive great apes, who would spend much more of their time engaged in foraging and other activities in the wild. Enrichment interventions have the potential to alleviate the adverse...

Harper, S. B., Bayne, K., Anderson, K. E. 2020. High-containment agriculture animal research: An AAALAC International perspective. ILAR Journal 61(1), 10-17.

Institutions that conduct high-containment agricultural research involving domestic livestock represent a specialized category of programs that are accredited by AAALAC International. The accreditation process includes a comprehensive assessment of the overall program of animal care...