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)...

Palermo Mendes, J., Ribeiro Caldara, F., de Castro Burbarelli, M. F. et al. 2023. Performance and welfare of sows exposed to auditory environmental enrichment in mixed or collective housing systems. Animals 13(7), 1226.

The research aimed to assess the effects of auditory environmental enrichment on sows in mixed housing (caged until 35 days after insemination and then collective pens) or collective housing (caged until 72 h after insemination...

Rørvang, M. V., Schild, S.-L. A., Stenfelt, J. et al. 2023. Odor exploration behavior of the domestic pig (Sus scrofa) as indicator of enriching properties of odors. Frontiers in Behavioral Neuroscience 17, 1173298.

Although the sense of smell in pigs is widely recognized as being highly developed, surprisingly little is known about their sensory ability. This study aimed to (a) identify which non-social odors pigs were able to...

Ruvira, S., Rodríguez-Rodríguez, P., Cañas, S. et al. 2023. Evaluation of parameters which influence voluntary ingestion of supplements in rats. Animals 13(11), 1827.

Drug safety and efficacy studies frequently use oral gavage, but repetitive usage may cause problems. Administration through voluntary ingestion represents an opportunity for refinement. We aimed to develop a protocol for voluntary ingestion of gelatin-based...

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...

Van Kerschaver, C., Turpin, D., Michiels, J. et al. 2023. Reducing weaning stress in piglets by pre-weaning socialization and gradual separation from the sow: A review. Animals 13(10), 1644.

The weaning of pigs in most commercial pork production systems is an abrupt event performed at a fairly young age, i.e., mostly between 2.5 and 5 weeks of age. This practice induces a stress response...

Monteiro, M. S., Muro, B. B. D., Carnevale, R. F. et al. 2023. The beneficial effects of providing prepartum sows with nesting materials on farrowing traits, piglet performance and maternal behavior: A systematic review and meta-analysis. Applied Animal Behaviour Science 259, 105795.

Sows are highly motivated to engage in nest-building behavior prior to farrowing. Studies have shown that providing nesting material to farrowing sows reduces the occurrence of redirected nest-building behaviors, improves farrowing traits and maternal behavior...

Vas, J., BenSassi, N., Vasdal, G. et al. 2023. Better welfare for broiler chickens given more types of environmental enrichments and more space to enjoy them. Applied Animal Behaviour Science 261, 105901.

Providing an increased variety of environmental enrichment options, with sufficient space to use them, could increase the behavioural expression of positive affective states in production animals. The goal of this study was to investigate associations...

Veldkamp, F., Garcia-Faria, T. I., Witjes, V. L. et al. 2023. Validation of non-invasive sensor technologies to measure interaction with enrichment material in weaned fattening pigs. Applied Animal Behaviour Science 263, 105923.

Measuring animal behaviour is important in the assessment of animal welfare. When interaction with the enrichment material (EM) can be measured, it can be used for detecting an increasing/decreasing interest in a certain EM. In...

Lobina, C., Maccioni, P., Gessa, G. L. et al. 2023. Exposure to an enriched environment exerts anxiolytic effects in Sardinian alcohol-preferring rats. Behavioural Brain Research 452, 114557.

Exposure to an enriched environment (EE) has been reported to generate multiple beneficial effects in rodents, including – among the many – amelioration of anxiety-related behaviors. The present study investigated whether living in an EE...

Núñez-Murrieta, M. A., Coria-Avila, G. A., Martínez, A. J. et al. 2023. Preterm rat survival is enhanced by gestational environmental enrichment. Behavioural Processes 205, 104820.

Throughout the last decade, the estimated global human preterm birth rate was 10.6 %, with higher rates in Asia, South America, and Africa. Preterm individuals, even in adulthood, are more likely to develop cardiorespiratory, renal...

Alvarez-Hernandez, N., Vallejo-Timarán, D., de Jesús Rodriguez, B. 2023. Adapted original music as an environmental enrichment in an intensive pig production system reduced aggression in weaned pigs during regrouping. Animals 13(23), 3599.

In intensive swine production systems,, the practice of regrouping unfamiliar pigs is common, often leading to aggressive behavior. Although the effect of different musical genres composed for humans has been evaluated in pigs to mitigate...

Esparza, K. 2023, August. Moving away from soiled bedding sentinels—The (R)evolution in rodent health screening. Animal Technology and Welfare 22(2), 158–160.

Traditional health monitoring methods consisted of Soiled Bedding Sentinels (SBS (i.e. animals exposed to dirty bedding from colony animals)), which require the euthanasia of SBS. Numerous studies have demonstrated that SBS may not accurately represent...

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...

Mählis, G., Kleine, A., Lüschow, D. et al. 2023. Clicker training as an applied refinement measure in chickens. Animals 13(24), 3836.

When using chickens in animal studies, the handling of these animals for sample collection or general examinations is considered stressful due to their prey nature. For the study presented here, plasma and salivary corticosterone as...

Ortín-Bustillo, A., Botía, M., López-Arjona, M. et al. 2023. Saliva sampling material matters: Effects on the results of saliva analysis in pigs. Animals 13(24), 3757.

The use of saliva as a biological sample from pigs is of high practical interest because blood collection from pigs is difficult and stressful. In this study, the influence of two different materials, a cotton...

Stevens, C., Hammonds, T., Hinchcliffe, J. et al. 2023. Report of the 2022 RSPCA/UFAW Rodent Welfare Group Meeting. Animal Technology and Welfare 22(2), 91–100.

The RSPCA/UFAW Rodent Welfare Group has held a one-day meeting every autumn for the last 29 years, so that its members can discuss current welfare research, exchange views on welfare issues and share experiences of...

Tough, B. 2023, August. Rat playpens—The effect on welfare, technical time and budget. Animal Technology and Welfare 22(2), 156–157.
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...

Sundman, E. R., Gabler, N. K., Millman, S. T. et al. 2022. The use of attractants to stimulate neonatal piglet interest in rope enrichment. Animals 12(2), 211.

In the United States swine industry, preweaning mortality represents the highest mortality rate of any production phase, nearly half attributed to crushing. The overarching aim of this study was to determine if enrichment ropes would...

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 =...

Ratuski, A. S., Weary, D. M. 2022. Environmental enrichment for rats and mice housed in laboratories: A metareview. Animals 12(4), 414.

Environmental enrichment has been widely studied in rodents, but there is no consensus on what enrichment should look like or what it should achieve. Inconsistent use of the term “enrichment” creates challenges in drawing conclusions...