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...

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...

Almeida, M. M., Cabrita, E., Fatsini, E. 2023. The use of sand substrate modulates dominance behaviour and brain gene expression in a flatfish species. Animals 13(6), 978.

Physical complexity adds physical enrichment to rearing conditions. This enrichment promotes fish welfare and reduces detrimental characteristics that fish develop in captivity. Senegalese sole (Solea senegalensis) is an important species for European aquaculture, where it...

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...

Diao, W., Jia, R., Hou, Y. et al. 2023. Effects of stocking density on the growth performance, physiological parameters, antioxidant status and lipid metabolism of Pelteobagrus fulvidraco in the integrated rice-fish farming system. Animals 13(11), 1721.

Pelteobagrus fulvidraco is a freshwater fish commonly raised in rice fields, yet the optimal stocking density for this species remains unknown. Therefore, this study aimed to investigate the appropriate stocking density of P. fulvidraco in...

Dong, Y., Fraley, G. S., Siegford, J. M. et al. 2023. Comparing different environmental enrichments for improving the welfare and walking ability of male turkeys. PLOS ONE 18(5), e0285347.

This study investigated age-related changes in turkey welfare measures (wounds, feather quality (FQ), feather cleanliness, and footpad condition (FCON)) and walking ability (gait) as influenced by different types of environmental enrichment (EE). Tom turkeys (n...

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)...

Matrai, E., Chan, H. Y. A., Leung, F. M. et al. 2023. Point for enrichment, point for welfare—Testing use of a laser pointer with Arapaima gigas. Animals 13(8), 1370.

The arapaima (Arapaima gigas) is one of the largest freshwater fish species, known to exceed 3 m in total length. It is listed as Data Deficient by the IUCN. A. gigas is native to the...

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...

Pereira, E., Nääs, I. de A., Ivale, A. H. et al. 2023. Energy assessment from broiler chicks’ vocalization might help improve welfare and production. Animals 13(1), 15.

Vocalization seems to be a viable source of signal for assessing broiler welfare. However, it may require an understanding of the birds’ signals, both quantitatively and qualitatively. The delivery of calls with a specific set...

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...

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...

Baßmann, B., Hahn, L., Rebl, A. et al. 2023. Effects of stocking density, size, and external stress on growth and welfare of African catfish (Clarias gariepinus Burchell, 1822) in a commercial RAS. Fishes 8(2), 74.

The effects of semi-intensive (100 kg m−3), intensive (200 kg m−3), and super-intensive (400 kg m−3) stocking densities on the growth and welfare of African catfish (Clarias gariepinus) were investigated under commercial production conditions. Plasma...

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...

Contreras-Jodar, A., Escribano, D., Cerón, J. J. et al. 2023. Reducing stocking densities and using cooling systems for more adapted pigs to high temperatures when reared in intensive conditions. Animals 13(15), 2424.

This study is aimed at evaluating the effect of reducing stocking density and using cooling systems to mitigate the negative effects of high temperatures in growing pigs (females and castrated males) reared in intensive conditions...

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...

Olczak, K., Penar, W., Nowicki, J. et al. 2023. The role of sound in livestock farming—Selected aspects. Animals 13(14), 2307.

To ensure the optimal living conditions of farm animals, it is essential to understand how their senses work and the way in which they perceive their environment. Most animals have a different hearing range compared...

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...

Crone, C., Caldara, F. R., Martins, R. et al. 2023. Environmental enrichment for pig welfare during transport. Journal of Applied Animal Welfare Science 26(3), 393–403.

This study aimed to assess the effects of environmental enrichment for pigs during transportation in different phases of their productive cycle. Two trials were conducted, the first during transportation of pigs from the piglet production...

Fazekas, G., Müller, T., Stanivuk, J. et al. 2023. Evaluation of applying environmental enrichment to sterlets (Acipenser ruthenus L.) in early life stages. Applied Animal Behaviour Science 268, 106090.

Traditional aquaculture farming conditions favour the development of maladaptive traits of reared fish. The hatchery releases are a crucial part of the population recovery action in sturgeon species. The manipulation of the environment could be...

Hanh, H. Q., Phuong, N. T., Tien, N. D. et al. 2023. Effects of stocking density in group cages on egg production, profitability, and aggressive pecking of hens. Journal of Applied Animal Welfare Science 26(3), 374–385.

There is an increasing concern about welfare issues related to battery cages, which are commonly used in Vietnam, and requires a modified cage that improves hen welfare while retaining its economic and management advantages. We...

Kim, J., Lee, J., Kang, K. et al. 2023. Effects of sling belt provision on behaviour, skin lesions, and salivary cortisol level in growing pigs after transport and regrouping. Applied Animal Behaviour Science 269, 106116.

The provision of enrichment material has been widely recommended to mitigate stress and minimise aggressive behaviour as well as enhance the welfare of pigs after transport and regrouping. In this study, we assessed the effects...

Nyqvist, D., Schiavon, A., Candiotto, A. et al. 2023. PIT-tagging Italian spined loach (Cobitis bilineata): Methodology, survival and behavioural effects. Journal of Fish Biology 102(3), 575–580.

The Italian spined loach (Cobitis bilineata) is an elongated, small-sized (

Rørvang, M. V., Schild, S.-L. A., Wallenbeck, A. et al. 2023. Rub ‘n’ roll – Pigs, Sus scrofa domesticus, display rubbing and rolling behaviour when exposed to odours. Applied Animal Behaviour Science 266, 106022.

Pigs are regarded as having a highly developed sense of smell, although scientific information on the topic is sparse. Here, we describe two behaviours unexpectedly observed in a study assessing pigs’ responses to odours and...

Vargas, L. B., Caldara, F. R., Lippi, I. C. de C. et al. 2023. Environmental enrichment strategies for weaned pigs: Welfare and behavior. Journal of Applied Animal Welfare Science 26(2), 205–217.

This research aims to evaluate the effects of different types and strategies of environmental enrichment for weaned pigs on behavior. Forty weaned piglets aged 21 to 28 days were distributed in a completely randomized design...