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. 
Lambert, H., Cornish, A., Waley, D. 2024. The value of regulating stocking densities in aquaculture must not be dismissed: A reply to Saraiva et al. 2022. Frontiers in Veterinary Science 10.

We would like to rebut the argument made by Saraiva et al. (1) in their paper “Finding the “golden stocking density”: a balance between fish welfare and farmers' perspectives,” that stocking densities should not be...

Evans, L., Brooks, G. C., Anderson, M. G. et al. 2023. Environmental complexity and reduced stocking density promote positive behavioral outcomes in broiler chickens. Animals 13(13), 2074.

The objective was to evaluate the impacts of a complex environment and stocking density on Ross 708 broiler chicken behaviors. Eight pens contained either high complexity (HC) or low complexity (LC) environments, and high (HD)...

Papakitsos, G., Assouad, S., Papageorgiou, M. et al. 2023. Regrouping in dairy ewes—Effects on productive performance and specific behavioral traits. Animals 13(7), 1163.

The regrouping of ruminants is a common practice in dairy farms and is targeting at the improvement of milk production efficiency. However, changing the established hierarchy in a group affects both productivity and behavioral attributes...

Cavieres, G., Bozinovic, F., Bogdanovich, J. M. et al. 2023. Impact of prolonged chronic social isolation stress on behavior and multifractal complexity of metabolic rate in Octodon degus. Frontiers in Behavioral Neuroscience 17.

Social interaction can improve animal performance through the prevention of stress-related events, the provision of security, and the enhancement of reproductive output and survival. We investigated the effects of prolonged chronic social isolation stress on...

Leeds, A., Riley, A., Terry, M. et al. 2022. Out of sight, out of mind or just something in the way? Visual barriers do not reduce intraspecific agonism in an all-male group of Nile crocodiles (Crocodylus niloticus). Animals 12(3), 269.

Here, we evaluated if visual barriers could reduce intraspecific agonism in an all-male group of Nile crocodiles (Crocodylus niloticus) living in a zoo. Crocodiles were monitored for nearly 100 h, and four “hotspots” of aggression...

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...

Lee, V. E., Arnott, G., Turner, S. P. 2022. Social behavior in farm animals: Applying fundamental theory to improve animal welfare. Frontiers in Veterinary Science 9, 932217.

A fundamental understanding of behavior is essential to improving the welfare of billions of farm animals around the world. Despite living in an environment managed by humans, farm animals are still capable of making important...

Mayes, B. T., Tait, L. A., Cowley, F. C. et al. 2022. Stocking density, restricted trough space, and implications for sheep behaviour and biological functioning. Frontiers in Veterinary Science 9, 965635.

Stocking density and trough space allowance can potentially impact sheep welfare during live export voyages. The aim of this study was to assess the welfare implications for sheep housed at five allometric stocking densities, with...

Saraiva, J. L., Rachinas-Lopes, P., Arechavala-Lopez, P. 2022. Finding the “golden stocking density”: A balance between fish welfare and farmers’ perspectives. Frontiers in Veterinary Science 9, 930221.

The effects of stocking density on fish welfare are complex and involve many interacting parameters. This complex relationship between fish welfare, stocking density and influencing factors make it challenging to define a specific optimal (“golden”)...

Schwarzer, A., Erhard, M., Schmidt, P. et al. 2022. Effects of stocking rate and environmental enrichment on the ontogeny of pecking behavior of laying hen pullets confined in aviary compartments during the first 4 weeks of life. Animals 12(19), 2639.

The objective of this study was to describe the ontogeny of the severe feather pecking (SFP), gentle feather pecking (GFP), aggressive pecking (AP), and enrichment pecking (EP) of non-beak-trimmed Lohmann Brown (LB)-pullets during the first...

van der Eijk, J. A. J., Gunnink, H., Melis, M. et al. 2022. Reducing stocking density benefits behaviour of fast- and slower-growing broilers. Applied Animal Behaviour Science 257, 105754.

The broiler industry has come under sustained pressure from welfare organizations to improve broiler welfare. Breed and stocking density are important factors for broiler welfare and are often specified as criteria for higher welfare systems...

Gilmour, K. M., Bard, B. 2022. Social buffering of the stress response: Insights from fishes. Biology Letters 18(10), 20220332.

Social buffering of stress refers to the effect of a social partner in reducing the cortisol or corticosterone response to a stressor. It has been well studied in mammals, particularly those that form pair bonds...

Phillips, H. N., Heins, B. J. 2021. Effects of outdoor stocking density on growth, feather damage and behavior of slow-growing free-range broilers. Animals 11(3), 688.

Access to pasture is a main benefit of free-range broiler housing systems, yet the level of outdoor stocking density on broiler animal welfare remains unsettled. The growth, feather damage, pasture ranging and behaviors were assessed...

Yu, J. H., Brown, J., Boisseau, N. et al. 2021. Effects of Lupron and surgical castration on fecal androgen metabolite concentrations and intermale aggression in capybaras (Hydrochoerus hydrochaeris). Zoo Biology 40(2), 135-141.

To curb agonistic interactions in a bachelor group of three male capybaras (Hydrochoerus hydrochaeris), a single dose of leuprolide acetate (Lupron®) was used in an attempt to chemically sterilize the males. Concurrently, fecal androgen metabolite...

Anderson, M. G., Campbell, A. M., Crump, A. et al. 2021. Effect of environmental complexity and stocking density on fear and anxiety in broiler chickens. Animals 11(8), 2383.

Barren housing and high stocking densities may contribute to negative affective states in broiler chickens, reducing their welfare. We investigated the effects of environmental complexity and stocking density on broilers’ attention bias (measure of anxiety)...

Forslind, S., Blokhuis, H. J., Riber, A. B. 2021. Disturbance of resting behaviour of broilers under different environmental conditions. Applied Animal Behaviour Science 242, 105425.

Resting behaviours make up a large part of the daily time budget of broilers. However, in intensive broiler production systems disruptions of resting behaviours occur, where resting individuals get disturbed by active individuals. Such interruptions...

da Silva Medeiros Elidio, H., Coelho, J. W. R., Cavalcanti Pereira da Silva, L. C. et al. 2021. Housing density and aggression in Syrian hamsters. JAALAS 60(5), 506-509.

The Syrian hamster (Mesocricetus auratus) is a solitary and naturally territorial animal, with female hamsters being more aggressive than males. This behavior makes handling difficult because they are usually housed in groups, which can lead...

Orient, E., Guillén-Salazar, F. 2021. The effects of alpha male removal on the social behavior of a group of olive baboons (Papio anubis). Journal of Applied Animal Welfare Science 24(4), 424-433.

In captivity, the managers of primate populations have removed individuals from their groups for medical and social reasons, but there has been little documentation regarding the consequences of this extraction on the sociality of the...

Insel, N., Shambaugh, K. L., Beery, A. K. 2020. Female degus show high sociality but no preference for familiar peers. Behavioural Processes 174, 104102.

Group-living animals vary in social behavior across multiple dimensions, including in the selectivity of social interactions with familiar versus unfamiliar peers. Standardized behavioral tests can be used to tease apart different dimensions of behavior. These...

Vittis, Y., Kaler, J. 2020. Environmental and field characteristics associated with lameness in sheep: A study using a smartphone lameness app for data recording. Veterinary Record 186(12), 384.

Sheep lameness is a major concern among farmers and policymakers with significant impacts on animal welfare standards as well as financial and production performance. The present study attempts to identify the relative importance of environmental...

Skinner, M., Miller, N. 2020. Aggregation and social interaction in garter snakes (Thamnophis sirtalis sirtalis). Behavioral Ecology and Sociobiology 74, 51.

Previous research has shown that competition, familiarity, diet, and relatedness can all influence aggregation patterns in garter snakes. We controlled for these factors and examined social aggregation patterns in juvenile Eastern garter snakes (Thamnophis sirtalis...

Stevens, T., Williams, W. R. 2020. Tarps used as visual barriers decrease aggressive conflicts in baboons. Laboratory Animal Science Professional 8(5) (September/October), 72-74.

Nonhuman primate (NHP) colonies housed in research settings are manipulated frequently due to research protocols, for breeding, and for veterinary procedures. These manipulations come with maneuvering complex group dynamics that can be challenging for baboon...

Acharya, R., Rault, J.-L. 2020. Risk factors for feather-damaging behavior in companion parrots: A social media study. Journal of Veterinary Behavior 40, 43-49.

Studies on the etiology of behavioral problems often involve interference in the animal's routine or reliance on owners' self-reports like surveys. Gathering data from videos posted on social media, a technique coined ‘video mining’, offers...

Borland, J. M., Kim, E., Swanson, S. P. et al. 2020. Effect of aggressive experience in female Syrian hamsters on glutamate receptor expression in the nucleus accumbens. Frontiers in Behavioral Neuroscience 14, 583395.

Our social relationships determine our health and well-being. In rodent models, there is now strong support for the rewarding properties of aggressive or assertive behaviors to be critical for the expression and development of adaptive...

Pedersen, I. J., Forkman, B. 2019. Improving leg health in broiler chickens: A systematic review of the effect of environmental enrichment. Animal Welfare 28(2), 215-230.

Leg problems are highly prevalent in modern broiler production and provision of environmental enrichment could be a strategy to improve leg health. Different types of environmental enrichment have undergone evaluation. Our objective was to conduct...