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. 
Taylor, P. S., Hemsworth, P. H., Rault, J.-L. 2022. Environmental complexity: Additional human visual contact reduced meat chickens’ fear of humans and physical items altered pecking behavior. Animals 12(3), 310.

Increased environmental complexity can improve animal welfare, depending on the resources provided and use by the animal. We provided chickens either with physical items that posed no biosecurity risk and were inexpensive (balls, chains, perches...

Escobedo-Bonilla, C. M., Quiros-Rojas, N. M., Rudín-Salazar, E. 2022. Rehabilitation of marine turtles and welfare improvement by application of environmental enrichment strategies. Animals 12(3), 282.

Sea turtles perform various ecological services in several marine environments and are considered architects of the marine landscape. At present, they are endangered species due to anthropogenic threats, pollution and degradation of marine habitats. These...

Campbell, D. L. M., Belson, S., Dyall, T. R. et al. 2022. Impacts of rearing enrichments on pullets’ and free-range hens’ positive behaviors across the flock cycle. Animals 12(3), 280.

Enrichment during the indoor rearing of pullets destined for free-range systems may optimize pullet development including increasing motivated natural behaviors (termed ‘positive behaviors’) including foraging, dust bathing and chick play. Hy-Line Brown® chicks (n =...

Xu, C., Hou, M., Su, L. et al. 2022. The effect of environmental enrichment on laboratory rare minnows (Gobiocypris rarus): Growth, physiology, and behavior. Animals 12(4), 514.

Environmental enrichment is a method to increase environmental heterogeneity, which may reduce stress and improve animal welfare. Previous studies have shown that environmental enrichment can increase the growth rate, decrease aggressive and anxiety-like behaviors, improve...

Rowe, E., Mullan, S. 2022. Advancing a “good life” for farm animals: Development of resource tier frameworks for on-farm assessment of positive welfare for beef cattle, broiler chicken and pigs. Animals 12(5), 565.

There is increasing recognition that farm animal welfare standards should ensure positive welfare, as well as prevent negative welfare. Resources that are valued by an animal and that provide opportunities to engage in motivated behaviours...

Mocz, F., Michel, V., Janvrot, M. et al. 2022. Positive effects of elevated platforms and straw bales on the welfare of fast-growing broiler chickens reared at two different stocking densities. Animals 12(5), 542.

In conventional rearing systems, fast-growing broiler chickens commonly experience welfare issues, such as contact dermatitis, walking difficulties or a lack of expression of species-specific behaviours. Enriching their environment may be a way to improve their...

Baker, P. E., Nicol, C. J., Weeks, C. A. 2022. The effect of hard pecking enrichment during rear on feather cover, feather pecking behaviour and beak length in beak-trimmed and intact-beak laying hen pullets. Animals 12(6), 674.

Injurious pecking, commonly controlled by beak trimming (BT), is a widespread issue in laying hens associated with thwarted foraging. This controlled study compared the effect in intact and beak-trimmed pullets of providing pecking pans to...

Sandilands, V., Baker, L., Donbavand, J. et al. 2022. Do hens use enrichments provided in free-range systems? Animals 12(8), 995.

Hens in free-range systems are given enrichments to increase foraging and limit injurious pecking, but the efficacy of enrichment types requires investigation. We studied hen behaviour and feather cover in eight commercial free-range flocks each...

Diggins, R., Burrie, R., Ariel, E. et al. 2022. A review of welfare indicators for sea turtles undergoing rehabilitation, with emphasis on environmental enrichment. Animal Welfare 31(2), 219-230.

For animals undergoing rehabilitation it is vital to monitor welfare in a way that is feasible, practical, and limits stress to the animal. The industry gold standard is to assess welfare under the Five Domains...

Kapusta, J., Kruczek, M., Pochroń, E. et al. 2022. Welfare of encaged rodents: Species specific behavioral reaction of voles to new enrichment items. Applied Animal Behaviour Science 246, 105522.

The enrichment of the environment of captive animals is one of the methods applied to reduce stress of the animals and to assure their proper welfare. However, placing objects in a limited space of a...

Vasdal, G., Gebhardt-Henrich, S.G., Kittelsen, K.E. et al. 2022. Commercial broiler breeder pullet hens use perches but show no preference for perch type or height. Applied Animal Behaviour Science 249, 105608.

An important behavioral need for laying hens is perching, but few studies have investigated perching behavior in commercial broiler breeder pullets. The aim of this study was to investigate perching behavior throughout the pullet period...

Griffioen, A. B., Janssen, W., Menke,T. et al. 2022. Does tagging transparent fish increase predation risk? A laboratory study with glass eel (Anguilla anguilla) and sea bass (Dicentrarchus labrax). Journal of Fish Biology 100(1), 184-191.

Barriers in the estuaries of the rivers prevent the immigration of glass eels (Anguilla anguilla) arriving on the European coast every spring. This leads to an unnatural accumulation of migrating glass eels below the barriers...

Swarr, T. R., Myrick, C. A., Fitzpatrick, R. M. 2022. Tag retention in and effects of passive integrated transponder tagging on survival and swimming performance of a small-bodied darter. Journal of Fish Biology 100(3), 705-714.

Fisheries biologists have been hesitant to use passive integrated transponder (PIT) tags in small-bodied fishes (40–200 mm TL) such as darters (Percidae: Etheostomatinae) because of the fishes' size and potential effect on swimming performance. The authors used...

Medina, A. 2022. Creative enrichment for nonhuman primates. Laboratory Animal Science Professional 10(1) (January/February), 42-43.

Providing novel and creative enrichments for nonhuman primates improves their mental wellbeing and is thus an important aspect of all husbandry programs. These enrichments are often presented through variations in diet, toys, and environmental features...

Buchanan, K. 2022. DIY: Ants on a log. Laboratory Animal Science Professional 10(1) (January/February), 44.

This traditional snack has a variety of options for NHP enrichment. From fruit to cereals, get creative with the “ants” and remember to consider different fillings for the celery log.

Lane, S., Williams, W., Mayo, M. 2022. The impact of environmental enrichment on red-eared slider turtles (Trachemys elegans). Laboratory Animal Science Professional 10(3) (May/June), 18-20.

This study aimed to determine whether tank enrichment improved positive species-specific behaviors (those that benefit the animals' overall well-being), such as basking, and/or decreased negative behaviors (those that may indicate stress, agitation, or discomfort), such...

Birolo, M., Trocino, A., Zuffellato, A. et al. 2022. Use of gnawing hay blocks: Effects on productive performance, behavior and reactivity of growing rabbits kept in parks with different sex-group compositions. Animals 12(9), 1212.

To improve animal welfare in collective park housing systems, this study assessed the effects of the provision of gnawing hay blocks and the group composition (F: females, M: males, FM: mixed sex) on performance, behavior...

Son, J., Lee, W.-D., Kim, H.-J. et al. 2022. Effect of providing environmental enrichment into aviary house on the welfare of laying hens. Animals 12(9), 1165.

This study aimed to determine the effects of providing environmental enrichment materials—pumice stone and alfalfa hay—to laying hens in the aviary system. A total of 2196 40-week-old Hy-Line Brown laying hens were randomly allotted to...

Vasdal, G., Gebhardt-Henrich, S. G., Tahamtani, F. et al. 2022. Perch use in commercial broiler breeders – Preference for perch material and effect of age. Applied Animal Behaviour Science 253, 105680.

Unlike for laying hens in most European countries, few broiler breeders have access to perches, and there is a need for more knowledge on perching behavior in broiler breeders. The aim of this study was...

Ojelade, O. C., Durosaro, S. O., Akinde, A. O. et al. 2022. Environmental enrichment improves the growth rate, behavioral and physiological response of juveniles of Clarias gariepinus under laboratory conditions. Frontiers in Veterinary Science 9, 980364.

Environmental enrichment (EE) improves the growth rate and welfare of some cultured fishes. However, most cultured fish species are raised in non-enriched housing conditions. Clarias gariepinus is an important commercial fish species, but little is...

Sanders, K., Fernandez, E. J. 2022. Behavioral implications of enrichment for golden lion tamarins: A tool for ex situ conservation. Journal of Applied Animal Welfare Science 25(3), 214-223.

The re-release of golden lion tamarins (Leontopithecus rosalia), from zoos into the wild, is considered to be an ex situ conservation success story. However, zoo-born golden lion tamarins have lower survival rates than their wild-born...

Runde, B. J., Buckel, J. A., Bacheler, N. M. et al. 2022. Evaluation of six methods for external attachment of electronic tags to fish: Assessment of tag retention, growth and fish welfare. Journal of Fish Biology 101(3), 419-430.

External attachment of electronic tags has been increasingly used in fish studies. Many researchers have used ad hoc attachment methods and provided little or no validation for the assumption that tagging itself does not bias...

Lennox, R. J., Stöger, E., Dahlmo, L. S. et al. 2022. Effects of tag type and surgery on migration of Atlantic salmon (Salmo salar) smolts. Journal of Fish Biology 101(3), 515-521.

Tagging salmon smolts to provide information about the timing of outmigration has been a common approach to monitor phenology and model the risk of encountering stressors. However, the validity of tagging has come under scrutiny...

Alaniz, A. J., Astudillo-Hinojosa, K., Soto, A. F. et al. 2022. Rapid behavioral recovery based on environmental enrichment of a white-throated toucan (Ramphastos tucanus: Ramphastidae) affected by collision trauma. Journal of Veterinary Behavior 57, 1-5.

Captive animals that have experienced traumatic events require a high range of care prior to reintroducing them into their natural habitat; and this care should ensure their welfare in captivity. This report shows the ethological...

Hurley, A., Cotton, A. 2022. Foraging enrichment affects behaviour and enclosure utilisation in captive male gelada Theropithecus gelada. Journal of Zoo and Aquarium Research 10(3), 129-138.

Enrichment devices are important tools to engage zoo-housed animals in species-specific natural behaviours, which is critical to ensure animal welfare. The gelada Theropithecus gelada has a unique graminivorous feeding ecology, yet there is minimal enrichment...