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. 
Alig, B. N., Ferket, P. R., Malheiros, R. D. et al. 2023. The effect of housing environment on commercial brown egg layer production, USDA grade and USDA size distribution. Animals 13(4), 694

Consumer demand for retail cage-free eggs is driving the layer industry towards greater use of extensive housing environments. However, there is limited research on how these environments affect egg production characteristics of brown egg layers...

da Silva, M. I. L., Paz, I. C. de L. A., Jacinto, A. S. et al. 2023. Providing environmental enrichments can reduce subclinical spondylolisthesis prevalence without affecting performance in broiler chickens. PLOS ONE 18(4), e0284087.

Environmental enrichment can increase the occurrence of natural behavior and improve leg health and other animal welfare outcomes in broiler chickens. This study aimed to assess the effects of three environmental enrichments, specifically hay bales...

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)...

Krunt, O., Zita, L., Kraus, A. et al. 2023. Effects of genotype and housing system on rabbit does’ aggressive behaviors and injuries in smallholding conditions. Animals 13(8), 1357.

The objective of the study was to investigate the effects of housing (deep litter + concrete floor vs. deep litter + ground soil with the possibility to dig burrows), and genotype (Mecklenburg or Hyplus) on...

Morgado, J. N., Lamonaca, E., Santeramo, F. G. et al. 2023. Effects of management strategies on animal welfare and productivity under heat stress: A synthesis. Frontiers in Veterinary Science 10, 1145610.

Climate change includes different dramatic events, and among them, heat stress exposition is the strongest phenomenon affecting the livestock sector. The effects of heat stress events on animal welfare are complex and the economic impacts...

Paneru, B., Pent, G. J., Nastasi, S. et al. 2023. Effect of silvopasture system on fearfulness and leg health in fast-growing broiler chickens. PLOS ONE 18(3), e0282923.

A silvopasture system intentionally integrates trees, forages, and livestock, allowing dual land use. These systems can provide high-quality habitat for broiler chickens; however, such systems have not been widely adopted by the broiler industry in...

Skånberg, L., Newberry, R. C., Estevez, I. et al. 2023. Environmental change or choice during early rearing improves behavioural adaptability in laying hen chicks. Scientific Reports 13(1), 6178.

Laying hens are typically moved to a novel environment after rearing, requiring adaptability to cope with change. We hypothesized that the standard rearing of laying hen chicks, in non-changing environments with limited choices (a single...

Sokołowicz, Z., Dykiel, M., Topczewska, J. et al. 2023. A comparison of the plumage condition of three egg-laying poultry genotypes housed in non-cage systems. Animals 13(2), 185.

The study covered a total of 810 hens in 3 groups (housing systems) of 270 hens each. The plumage condition of laying hens raised in various types of alternative housing systems, i.e., in deep litter...

Grandin, T. 2023. A practical approach to providing environmental enrichment to pigs and broiler chickens housed in intensive systems. Animals 13(14), 2372.

In Europe, regulations contain guidance to maintain high standards of animal welfare. In many parts of the world, large buyers for supermarkets or restaurants are the main enforcers of basic animal welfare standards. They can...

Montalcini, C. M., Petelle, M. B., Toscano, M. J. 2023. Commercial hatchery practices have long-lasting effects on laying hens’ spatial behaviour and health. PLOS ONE 18(12), e0295560.

The commercial hatchery process is globally standardized and exposes billions of day-old layer chicks to stress every year. By alleviating this early stress, on-farm hatching is thought to improve animal welfare, yet little is known...

Zhao, S., Cui, W., Yin, G. et al. 2023. Effects of different auditory environments on behavior, learning ability, and fearfulness in 4-week-old laying hen chicks. Animals 13(19), 3022.

Environmental enrichment can improve animal welfare. As a method of environmental enrichment, the effect of different auditory stimulations on the behavior response and welfare of laying hen chicks has yet to be investigated. Therefore, this...

Parés, R., Llonch, P., Such, X. et al. 2023. Wool-pulling behaviour appears in a production system with grazing restriction and can be assessed through wool inspection. Applied Animal Behaviour Science 269, 106109.

Sheep flocks can be reared in different production systems that differ in the duration of indoor housing and grazing restriction. Indoor housing can lead to aggressive interactions, such as blocking, threats and butts, whereas grazing...

de Oliveira sans, E. C., Dahlke, F., Freitas Federici, J. et al. 2023. Welfare of broiler chickens in Brazilian free-range versus intensive indoor production systems. Journal of Applied Animal Welfare Science 26(4), 505–517.

We compared broiler chicken welfare in free-range (FR) and intensive indoor (IN) systems using the Welfare Quality® Protocol. Ten FR and 11 IN farms in Brazil were assessed. Results are shown as either scores ranging...

Wei, H., Geng, L., Shang, X. et al. 2023. Background color preference of amphibian Rana dybowskii. Applied Animal Behaviour Science 268, 106079.

Background color may affect the welfare of the brown frog Rana dybowskii in captivity. To evaluate the perching platform color and feeding platform color preferences of brown frogs at day and night, a total of...

Zhao, S., Zhang, R., Li, C. et al. 2023. The effect of short-term classical music stimulus on behavior and tonic immobility reaction of pullets. Journal of Applied Animal Welfare Science 26(3), 386–392.

The purpose of this study was to investigate the effect of short-term stimulation of classical music on the behavior of pullets and to explore whether classical music as an auditory enrichment factor reduces the fear...

Rana, M. S., Lee, C., Lea, J. M. et al. 2022. Commercial free-range laying hens’ preferences for shelters with different sunlight filtering percentages. Animals 12(3), 344.

Extreme sunlight might be aversive to free-range laying hens, discouraging them from going outside. Range enrichment with artificial shelters may protect hens from sunlight and increase range use. The preferences of 34–40-week-old Hy-Line Brown laying...

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...

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 =...

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...

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...

Mels, C., Niebuhr, K., Futschik, A. et al. 2022. Predictors for plumage damage and bloody lesions indicative of feather pecking in pullets reared in aviaries. Applied Animal Behaviour Science 250, 105607.

Feather pecking remains a serious problem in poultry farming. This study aimed to identify risk factors for plumage damage as a proxy for feather pecking, and the predictive value of practical animal-based parameters. Data were...

Stephenson, E., Haskell, M. J. 2022. The use of a “go/go” cognitive bias task and response to a novel object to assess the effect of housing enrichment in sheep (Ovis aries). Journal of Applied Animal Welfare Science 25(1), 62-74.

It is widely acknowledged that environmental enrichment can improve animals’ welfare and emotional state. This study used cognitive bias and response to a novel object to assess the effect of enriched housing on emotional state...