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. 
Machado, S. P., Caldara, F. R., Foppa, L. et al. 2017. Behavior of pigs reared in enriched environment: Alternatives to extend pigs attention. PLOS ONE 12(1), e0168427.

Three trials were carried out in a completely randomized design aiming to assess the behavior of pigs in growth phase in enriched environments. Trial 1 evaluated the effects of frequency of availability of environmental enrichment...

Winfield, J., Macnamara, G., Macnamara, B. et al. 2017. Environmental enrichment for sucker and weaner pigs: The effect of enrichment block shape on the behavioural interaction by pigs with the blocks. Animals 7(12), 91.

This experiment tested the effect of enrichment-block shape on oro-nasal contact by young pigs, and possible habituation to the blocks. Nineteen litters (197 piglets) were randomly allocated to one of three block-shape treatments: Cube, Brick...

Vermeer, H., Dirx-Kuijken, N., Bracke, M. 2017. Exploration feeding and higher space allocation improve welfare of growing-finishing pigs. Animals 7(5), 36.

Lack of environmental enrichment and high stocking densities in growing-finishing pigs can lead to adverse social behaviors directed to pen mates, resulting in skin lesions, lameness, and tail biting. The objective of the study was...

Nordquist, R., van der Staay, F., van Eerdenburg, F. et al. 2017. Mutilating procedures, management practices, and housing conditions that may affect the welfare of farm animals: Implications for welfare research. Animals 7(2), 12.

A number of mutilating procedures, such as dehorning in cattle and goats and beak trimming in laying hens, are common in farm animal husbandry systems in an attempt to prevent or solve problems, such as...

Backus, B. L., Sutherland, M. A., Brooks, T. A. 2017. Relationship between environmental enrichment and the response to novelty in laboratory-housed pigs. JAALAS 56(6), 735-741.

Environmental enrichment is the enhancement of the physical or social environment in which an animal lives with the goal to improve its quality of life. Our objective was to investigate the effect of providing environmental...

Brown, S. M., Peters, R., Lawrence, A. B. 2017. Up-regulation of IGF-1 in the frontal cortex of piglets exposed to an environmentally enriched arena. Physiology & Behavior 173, 285-292.

Environmental enrichment (EE) is widely used in the life sciences to study effects of environment on the brain. In pigs, despite lack of EE being a key welfare issue there is little understanding of brain...

Palmer, S. 2017. Rescue-Enrich-Release: The environmental enrichment program for three species of captive primates at Colobus. Canopy 17(2), 27-30.

It is widely known that the psychological wellbeing of captive animals can become compromised by a captive environment that lacks proper environmental stimulation. Environmental enrichment programs have become the norm in captive environments yet research...

Alligood, C. A., Dorey, N. R., Mehrkam, L. R. et al. 2017. Applying behavior-analytic methodology to the science and practice of environmental enrichment in zoos and aquariums. Zoo Biology 36(3), 175–185.

Environmental enrichment in zoos and aquariums is often evaluated at two overlapping levels: published research and day‐to‐day institutional record keeping. Several authors have discussed ongoing challenges with small sample sizes in between‐groups zoological research and...

Nelson Slater, M., Hauber, M. E. 2017. Olfactory enrichment and scent cue associative learning in captive birds of prey. Zoo Biology 36(2), 120–126.

As the use of enrichment in zoos has become a standardized husbandry practice, the continued improvement of enrichment programs should be concomitant with empirical validation of those practices. The role of scent as enrichment remains...

Carlson, A., Allen, C., Skoumbourdis, E. et al. 2017. Cooked food for non-human primates: A discussion by the Laboratory Animal Refinement & Enrichment Forum. Animal Technology and Welfare 16(2), 124-126.

"Do any of you give cooked food like pasta, potatoes or vegetables to non-human primates? What’s your experience? Do the animals benefit from cooked food; do they like it; does it affect their health in...

Coleman, K., Novak, M. A. 2017. Environmental enrichment in the 21st century. ILAR Journal 58(2), 295-307.

More than a quarter of a century has elapsed since the Animal Welfare Act mandated that research facilities develop and follow a plan to promote the psychological well-being of captive primates. Since passage of this...

Nasirahmadi, A., Edwards, S. A., Matheson, S. M. et al. 2017. Using automated image analysis in pig behavioural research: Assessment of the influence of enrichment substrate provision on lying behaviour. Applied Animal Behaviour Science 196, 30-35.

Visual monitoring of pig behaviours over long periods is very time consuming and has possibility for observer bias. Automated image processing techniques now give the potential to carry out behavioural research in a more effective...

Casal-Plana, N., Manteca, X., Dalmau, A. et al. 2017. Influence of enrichment material and herbal compounds in the behaviour and performance of growing pigs. Applied Animal Behaviour Science 195, 38-43.

Pigs reared in barren conditions are exposed to many different stressors, compromising their welfare and producing physiological and behavioural changes. The aim of this study was to assess the effect of environmental enrichment (EE) consisting...

van der Staay, F. J., van Zutphen, J. A., de Ridder, M. M. et al. 2017. Effects of environmental enrichment on decision-making behavior in pigs. Applied Animal Behaviour Science 194, 14-23.

The animal’s emotional state, potentially modulated by environmental conditions, may affect cognitive processes such as interpretation, judgement and decision making behaviour. The Iowa Gambling Task (IGT) is a common method to examine decision making behavior...

Sutherland, M. A., Backus, B. L., Brooks, T. A. 2017. The effect of needle-free administration of local anesthetic on the behavior and physiology of castrated pigs. Journal of Veterinary Behavior 21, 71-76.

Pigs are routinely castrated in many countries without giving pain relief, which is an animal welfare concern. The objectives of this study were to evaluate the stress caused by administering local anesthetic (LA) using a...

Gabriel, S. M., Riley, K. M., Spinks, W. A. et al. 2017. Husbandry, care and enrichment of diabetic Sinclair swine in the laboratory environment. Laboratory Animal Science Professional 5(3) (September), 53-57.

Health monitoring, enrichment, training procedures and techniques, as well as instructions for the care of vascular access ports, are outlined in this paper. The procedures described herein helped maintain a successful, long-term research population of...

Sands, C., Evans, C., Buckmaster, C. A. 2017. The grooming sleeve: Encouraging conspecific-like behavior and strengthening the human-animal bond. Laboratory Animal Science Professional 5(2) (June), 52-53.

The act of grooming has been found to greatly decrease stress, heart rate, and cortisol levels in nonhuman primates; this decrease in stress and cortisol is seen in the animal being groomed, as well as...

Lambert, K., Kimmer, M., Mitchell, E. 2017. Using braided cloth as a pig enrichment device. Laboratory Animal Science Professional 5(1) (March), 36-38.

While the provision of space is important, it is not enough on its own to satisfy the behavioral needs of the pig. Pigs are highly intelligent animals that require complexity in their environment to provide...

Roth, T. S., Bionda, T. R., Sterck, E. H. M. 2017. Recapturing the canopy: Stimulating Bornean orang-utan (Pongo pygmaeus) natural locomotion behaviour in a zoo environment. Journal of Zoo and Aquarium Research 5(1), 16-24.

Orang-utans are the largest mainly arboreal animal: wild orang-utans rarely come to the forest floor. In contrast, the locomotion behaviour of captive orang-utans encompasses more time on the ground and they spend less time on...

Brown, J. L., Paris, S., Prado-Oviedo, N. A. 2016. Reproductive health assessment of female elephants in North American zoos and association of husbandry practices with reproductive dysfunction in African Elephants (Loxodonta africana). PLOS ONE 11(7), e0145673.

As part of a multi-institutional study of zoo elephant welfare, we evaluated female elephants managed by zoos accredited by the Association of Zoos and Aquariums and applied epidemiological methods to determine what factors in the...

van Dixhoorn, I. D. E., Reimert, I., Middelkoop, J. et al. 2016. Enriched housing reduces disease susceptibility to co-infection with porcine reproductive and respiratory virus (PRRSV) and Actinobacillus pleuropneumoniae (A. pleuropneumoniae) in young pigs. PLOS ONE 11(9), e0161832.

Until today, anti-microbial drugs have been the therapy of choice to combat bacterial diseases. Resistance against antibiotics is of growing concern in man and animals. Stress, caused by demanding environmental conditions, can reduce immune protection...

Meehan, C. L., Hogan, J. N., Bonaparte-Saller, M. K. et al. 2016. Housing and social environments of African (Loxodonta africana) and Asian (Elephas maximus) elephants in North American zoos. PLOS ONE 11(7), e0146703.

We evaluated 255 African (Loxodonta africana) and Asian (Elephas maximus) elephants living in 68 North American zoos over one year to quantify housing and social variables. All parameters were quantified for the both the day...

Hothersall, B., Whistance, L., Zedlacher, H. et al. 2016. Standardising the assessment of environmental enrichment and tail-docking legal requirements for finishing pigs in Europe. Animal Welfare 25(4), 499-515.

An online training package providing a concise synthesis of the scientific data underpinning EU legislation on enrichment and tail-docking of pigs was produced in seven languages, with the aim of improving consistency of professional judgements...

de Groot, B., Cheyne, S. M. 2016. Does mirror enrichment improve primate well-being? Animal Welfare 25(2), 163-170.

Primates are highly social animals and appropriate enrichment is required to ensure their psychological well-being. Mirrors are sometimes used as social or sensory environmental enrichment. In this paper we investigate the suitability of mirrors as...

Byrd, C. P., Winnicker, C., Gaskill, B. N. 2016. Instituting dark-colored cover to improve central space use within guinea pig enclosure. Journal of Applied Animal Welfare Science 19(4), 408-413.

Domestic guinea pigs (Cavia aperea f. porcellus) in laboratories have been shown to actively avoid the centers of their cages. This experiment tested a novel, dark-colored “shader” placed over the central portion of a cage...