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. 
Gabriel, P., Mastracchio, T., Bordner, K. et al. 2020. Impact of enriched environment during adolescence on adult social behavior, hippocampal synaptic density and dopamine D2 receptor expression in rats. Physiology & Behavior, 226, 113133.

Environmental enrichment (EE) is one experimental manipulation that induces changes in the brain. However, it is important to distinguish between physical and social components of enrichment. To this end we established four groups of rats...

Gebhardt-Henrich, S. G., Jordan, A., Toscano, M. J. et al. 2020. The effect of perches and aviary tiers on the mating behaviour of two hybrids of broiler breeders. Applied Animal Behaviour Science 233, 105145.

Broiler breeders are kept for the production of fertile eggs. They face serious welfare problems like aggressive behaviour of the males towards females during mating. Furthermore, broiler breeders are usually kept without perches which are...

Ipema, A. F., Gerrits, W. J. J., Bokkers, E. A. M. et al. 2020. Provisioning of live black soldier fly larvae (Hermetia illucens) benefits broiler activity and leg health in a frequency- and dose-dependent manner. Applied Animal Behaviour Science 230, 105082.

Fast-growing broilers spend most their time inactive and are therefore prone to experience leg problems. Environmental enrichment that facilitates intrinsically motivated behaviours can potentially promote activity and reduce leg problems, thereby improving broiler welfare. A...

Keymoradzadeh, A., Hedayati Ch, M., Abedinzade, M. et al. 2020. Enriched environment effect on lipopolysaccharide-induced spatial learning, memory impairment and hippocampal inflammatory cytokine levels in male rats. Behavioural Brain Research 394, 112814.

Neuro-inflammation is responsible for cognitive impairments and neurodegenerative diseases such as Alzheimer’s disease. In this study, we aimed to investigate the enriched environment (EE) effect on learning and memory impairment as well as on pro-inflammatory...

Liu, Z., Torrey, S., Newberry, R. C. et al. 2020. Play behaviour reduced by environmental enrichment in fast-growing broiler chickens. Applied Animal Behaviour Science 232, 105098.

The objective of this study was to evaluate effects of environmental enrichment on play behaviour in fast-growing broiler chickens. Chicks (19 of each sex) were randomly assigned to 6 non-enriched (NE) pens and 6 pens...

Modlinska, K., Chrzanowska, A., Pisula, W. 2020. Variability of enriched environment does not enhance the enrichment effect on food neophobia in rats (Rattus norvegicus). Behavioural Processes 180, 104221.

Many studies report differences between animals raised in an enriched environment and those living in standard conditions. Animals reared in enriched conditions demonstrate better memory and learning abilities, increased activity, reduced level of anxiety, etc...

Ross, M., Rausch, Q., Vandenberg, B. et al. 2020. Hens with benefits: Can environmental enrichment make chickens more resilient to stress? Physiology Behavior, 226, 113077.

Resilience, the degree to which individuals are physiologically and behaviourally impacted by stressors, can be enhanced by positive experiences (e.g. positive moods in human, environmental enrichment in rodents). Such effects are important for human health...

Woods, J. M., Lane, E. K., Miller, L. J. 2020. Preference assessments as a tool to evaluate environmental enrichment. Zoo Biology 39(6), 382-390.

Environmental enrichment is an important tool utilized to improve animal welfare in zoological institutions through opportunity for mental and physical stimulation. Many past studies have focused on the impact enrichment has on animal behavior; however...

Bari, M. S., Downing, J. A., Dyall, T. R. et al. 2020. Relationships between rearing enrichments, range use, and an environmental stressor for free-range laying hen welfare. Frontiers in Veterinary Science 7, 480.

Enrichments during pullet rearing may improve adaptation and welfare of hens as they move from indoor rearing to a free-range system. Individual variation in outdoor ranging may also affect welfare. This study assessed the effects...

Campbell, D. L. M., Dyall, T. R., Downing, J. A. et al. 2020. Rearing enrichments affected ranging behavior in free-range laying hens. Frontiers in Veterinary Science 7, 446.

Within Australia, free-range systems are prevalent, but pullets destined for range access are reared indoors. This mismatch between rearing and layer housing may hinder adaptation to the free-range environment. Rearing enrichments could enhance pullet development...

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...

Jung, L., Brenninkmeyer, C., Niebuhr, K. et al. 2020. Husbandry conditions and welfare outcomes in organic egg production in eight European countries. Animals 10(11), 2102.

In the European research project HealthyHens, welfare indicators as well as husbandry and management conditions were recorded in 107 organic laying hen farms in eight countries. Farms were visited at peak and end of lay...

Pullin, A. N., Temple, S. M., Bennett, D. C. et al. 2020. Pullet rearing affects collisions and perch use in enriched colony cage layer housing. Animals 10(8), 1269.

Hens reared in aviaries (AVI) as pullets have improved spatial abilities compared to hens reared in non-enriched cages (CON). However, this effect on behavior has been shown only to 23 weeks of age. Lohmann LSL-Lite...

Rokavec, N., Zupan Šemrov, M. 2020. Psychological and physiological stress in hens with bone damage. Frontiers in Veterinary Science 7, 589274.

Abnormalities in bone development in humans and non-humans can lead to impaired physical and psychological health; however, evidence is lacking regarding the role of individual psychosocial factors in the development of poor bone conditions. Addressing...

Rufener, C., Rentsch, A. K., Stratmann, A. et al. 2020. Perch positioning affects both laying hen locomotion and forces experienced at the keel. Animals 10(7), 1223.

The aim of this study was to assess the effect of perch positioning on laying hens’ locomotion and the resulting energy experienced at the keel. Twenty Nick Chick and 20 Brown Nick hens were trained...

de Castro Travnik, I., de Souza Machado, D., de Silva Gonçalves, L. et al. 2020. Temperament in domestic cats: A review of proximate mechanisms, methods of assessment, its effects on human—cat relationships, and one welfare. Animals 10(9), 1516.

Temperament can be defined as interindividual differences in behavior that are stable over time and in different contexts. The terms ‘personality’, ‘coping styles’, and ‘behavioral syndromes’ have also been used to describe these interindividual differences...

Veasey, J. S. 2020. Can zoos ever be big enough for large wild animals? A review using an expert panel assessment of the psychological priorities of the Amur tiger (Panthera tigris altaica) as a model species. Animals 10(9), 1536.

The ecology of large, wide-ranging carnivores appears to make them vulnerable to conservation challenges in the wild and welfare challenges in captivity. This poses an ethical dilemma for the zoo community and supports the case...

Schreiter, R., Damme, K., Freick, M. 2020. Edible environmental enrichments in littered housing systems: Do their effects on integument condition differ between commercial laying hen strains? Animals 10(12), 2434.

The aim of this study was to investigate the effect of additional enrichment materials (EMs; pecking stones and alfalfa bales) on the occurrence of plumage damage, skin injuries, and toe injuries, with an emphasis on...

Podturkin, A. A., Papaeva, N. 2020. Development of an environmental enrichment programme: Case study of white Bengal tiger (Panthera tigris bengalensis) and jaguar (Panthera onca) at Moscow Zoo. Journal of Zoo and Aquarium Research 8(2), 139-145.

Zoos are urged to implement enrichment programmes that include constant feedback to increase efficacy. However, such work is time consuming for zookeepers. The goal of this case study was to establish an enrichment programme in...

Rojas-Carvajal, M., Sequeira-Cordero, A., Brenes, J. C. 2020. Neurobehavioral effects of restricted and unpredictable environmental enrichment in rats. Frontiers in Pharmacology 11, 674.

To study how motivational factors modulate experience-dependent neurobehavioral plasticity, we modify a protocol of environmental enrichment (EE) in rats. We assumed that the benefits derived from EE might vary according to the level of incentive...

Tan, S. L. T., Handasyde, K. A., Rault, J.-L. et al. 2020. Insensitivity to reward shifts in zebrafish (Danio rerio) and implications for assessing affective states. Animal Cognition 23(1), 87–100

Theory and empirical findings predict that individuals in a negative affective state are more sensitive to unexpected reward loss and less sensitive to unexpected reward gain compared to individuals in a neutral or positive affective...

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...

Decina, C., Berke, O., van Staaveren, N. et al. 2019. An investigation of associations between management and feather damage in Canadian laying hens housed in furnished cages. Animals 9(4), 135.

Feather pecking is a continuous welfare challenge in the housing of egg-laying hens. Canada is currently making the transition from conventional cages to alternative housing systems. However, feather damage (FD) among laying hens due to...

Pisula, W., Modlinska, K., Chrzanowska, A. 2019. Behavioural response to the environmental changes of various types in Lister-Hooded male rats. Scientific Reports 9, 7111.

The animal preference for complexity is most clearly demonstrated when the environmental change takes the form of an increase in complexity. Therefore, one of the potential difficulties in interpretation is that the preference for perceptual...

Baxter, M., O’Connell, N. E. 2019. Does grouping environmental enrichments together affect the way they are used by commercially housed broiler chickens? Applied Animal Behaviour Science 210, 52-59.

Identifying the most attractive ways of presenting environmental enrichments in commercial broiler housing may encourage use and optimise their effectiveness. This study investigated the effect of grouping straw bales (SB), oat hulls (OH; as a...