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...

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...

Lupfer, G., Brandenburger, A., Machado, M. et al. 2023. Ultrasonic vocalizations near 30 kHz may indicate excitement rather than distress in female Wistar rats. Applied Animal Behaviour Science 261, 105881.

Rats emit ultrasonic vocalizations (USVs), sometimes referred to as 50-kHz vocalizations, during activities such as play and lower-frequency USVs, sometimes referred to as 22-kHz vocalizations, when experiencing distress. Definitions of 22-kHz vocalizations vary in terms...

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...

Broadfoot, C. K., Lenell, C., Kelm-Nelson, C. A. et al. 2023. Effects of social isolation on 50-kHz ultrasonic vocalizations, affective state, cognition, and neurotransmitter concentrations in the ventral tegmental and locus coeruleus of adult rats. Behavioural Brain Research 437, 114157.

Vocal communication, cognition, and affective state are key features of sustained health and wellness, and because vocalizations are often socially-motivated, social experience likely plays a role in these behaviors. The monoaminergic systems of the ventral...

Gauy, A. C. dos S., Bolognesi, M. C., Gonçalves-de-Freitas, E. 2023. Body tactile stimulation reduces the effects of high stocking density on the welfare of Nile tilapia (Oreochromis niloticus). Fishes 8(6), 320.

High stocking density is used in aquaculture to optimize farming. However, such strategies can stress territorial fish by increasing aggression, thus harming the fish welfare and productive performance. Here, we tested the effect of long-term...

Calisir, M., Yilmaz, O., Kolatan, H. E. et al. 2023. Effects of litter size and caging on physical and mental development in rats. Physiology & Behavior 267, 114200.

As a multidisciplinary field, laboratory animal science promotes or accelerates the emergence of innovative ideas and products. As research has increased, so has the demand for laboratory animals with reliable, standardized characteristics. Thus, the breeding...

Tivey, E. K. L., Martin, J. E., Brown, S. M. et al. 2022. Sex differences in 50 kHz call subtypes emitted during tickling-induced playful behaviour in rats. Scientific Reports 12(1), 15323.

‘Tickling’ induces positive affective states in laboratory rats as evidenced by the production of 50-kHz ultrasonic vocalisations (USVs), although this has mostly been investigated in males. Juvenile rats emit distinctive 50-kHz USV subtypes. Frequency-modulated (FM)...

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”)...

Seidisarouei, M., van Gurp, S., Pranic, N. M. et al. 2021. Distinct profiles of 50 kHz vocalizations differentiate between social versus non-social reward approach and consumption. Frontiers in Behavioral Neuroscience 15, 693698.

Social animals tend to possess an elaborate vocal communication repertoire, and rats are no exception. Rats utilize ultrasonic vocalizations (USVs) to communicate information about a wide range of socially relevant cues, as well as information...

Thoré, E. S. J., Brendonck, L., Pinceel, T. 2020. Conspecific density and environmental complexity impact behaviour of turquoise killifish (Nothobranchius furzeri). Fish Biology 97(5), 1448–1461.

Fish models are essential for research in many biological and medical disciplines. With a typical lifespan of only 6 months, the turquoise killifish (Nothobranchius furzeri) was recently established as a time- and cost-efficient model to...

Brudzynski, S. M. 2019. Emission of 22 kHz vocalizations in rats as an evolutionary equivalent of human crying: Relationship to depression. Behavioural Brain Research 363, 1-12.

There is no clear relationship between crying and depression based on human neuropsychiatric observations. This situation originates from lack of suitable animal models of human crying. In the present article, an attempt will be made...

Zaytseva, A. S., Volodin, I. A., Ilchenko, O. G. et al. 2019. Ultrasonic vocalization of pup and adult fat-tailed gerbils (Pachyuromys duprasi). PLOS ONE 14(7), e0219749.

Ultrasonic vocalizations (USVs) of laboratory rodents indicate animal emotional arousal and may serve as models of human disorders. We analysed spectrographically USV calls of pup and adult fat-tailed gerbils Pachyuromys duprasi during 420-s tests, including...

Santurtun, E., Broom, D. M., Phillips, C. J. C. 2018. A review of factors affecting the welfare of Atlantic salmon (Salmo salar). Animal Welfare 27(3), 193-204.

In the expanding salmon industry, many farmers use production methods that could result in poor welfare of the fish at various points of their lifecycle. We have reviewed methods used for producing salmon for food...

Champneys, T., Castaldo, G., Consuegra, S., et al. 2018. Density dependent changes in neophobia and stress-coping styles in the world’s oldest farmed fish. Royal Society Open Science 5(12), 181473.

Farmed fish are typically reared at densities much higher than those observed in the wild, but to what extent crowding results in abnormal behaviours that can impact welfare and stress coping styles is subject to...

Barker, T. H., George, R. P., Howarth, G. S. et al. 2017. Assessment of housing density, space allocation and social hierarchy of laboratory rats on behavioural measures of welfare. PLOS ONE 12(9), e0185135.

Minimum space allowances for laboratory rats are legislated based on weight and stocking rates, with the understanding that increased housing density encourages crowding stress. However, there is little evidence for these recommendations, especially when considering...

Burke, C. J., Kisko, T. M., Swiftwolfe, H. et al. 2017. Specific 50-kHz vocalizations are tightly linked to particular types of behavior in juvenile rats anticipating play. PLOS ONE 12(5), e0175841.

Rat ultrasonic vocalizations have been suggested to be either a byproduct of physical movement or, in the case of 50-kHz calls, a means to communicate positive affect. Yet there are up to 14 distinct types...

Pinelli, C., Leri, F., Turner, P. 2017. Long term physiologic and behavioural effects of housing density and environmental resource provision for adult male and female Sprague Dawley rats. Animals 7(6), 44.

There is considerable interest in refining laboratory rodent environments to promote animal well-being, as well as research reproducibility. Few studies have evaluated the long term impact of enhancing rodent environments with resources and additional cagemates...

Jones, T., Robinson, M., Leach, M. et al. 2017. Ultrasonic vocalisation as a measure of positive welfare in rats. Animal Technology and Welfare 16(2), 127-129.

Studies of animal welfare in laboratory animals have historically relied on the measurement of negative indicators rather than the assessment of positive indicators of welfare. Practical methods of welfare assessment are required to allow refinement...

Stevens, C. H., Croft, D. P., Paull, G. C. et al. 2017. Stress and welfare in ornamental fishes: What can be learned from aquaculture? Journal of Fish Biology 91(2), 409-428.

The ornamental fish trade is estimated to handle up to 1.5 billion fishes. Transportation and handling of fishes imposes a range of stressors that can result in mortality at rates of up to 73%. Given...

Sánchez-Muros, M. J., Sánchez, B., Barroso, F. G. et al. 2016. Effects of culture densities on feed demand, behavioural tests and on the hepatic and cerebral oxidative status in tilapia (Oreochromis sp.). Applied Animal Behaviour Science 185, 137-145.

The present study examines whether fish density affects behavioural tests, feed demand, and different parameters indicative of the oxidative status of the liver and brain of Orechromis sp. to identify welfare indicators for fish culturing...

Kisko, T. M., Himmler, B. T., Himmler, S. M. et al. 2015. Are 50-kHz calls used as play signals in the playful interactions of rats? II. Evidence from the effects of devocalization. Behavoural Processes 111, 25-33.

During playful interactions, juvenile rats emit many 50-kHz ultrasonic vocalizations, which are associated with a positive affective state. In addition, these calls may also serve a communicative role – as play signals that promote playful...

Kisko, T. M., Euston, D. R., Pellis, S. M. 2015. Are 50-khz calls used as play signals in the playful interactions of rats? III. The effects of devocalization on play with unfamiliar partners as juveniles and as adults. Behavioural Processes 113, 113-121.

When playing, rats emit 50-kHz calls which may function as play signals. A previous study using devocalized rats provides support for the hypothesis that 50-kHz function to promote and maintain playful interactions (Kisko et al...

Himmler, B.T., Kisko, T.M., Euston, D.R. et al. 2014. Are 50-kHz calls used as play signals in the playful interaction of rats? I. Evidence from the timing and context of their use. Behavioural Processes 106, 60-66.

During playful interactions, rats emit increased levels of 50-kHz vocalizations. It is possible that these vocalizations are used as play signals that promote and maintain playful contact. The study investigated this possibility. It was predicted...

Yuki, S., Okanoya, K. 2014. Behavioral correlates of 50-kHz ultrasonic vocalizations in rats: Progressive operant discrimination learning reduces frequency modulation and increases overall amplitude. Animal Behavior and Cognition 1(4), 452–463.

Ultrasonic vocalizations (USVs) in rats are thought to contain ecological signals reflecting emotional states. These USVs are centered on 50-kHz, and frequency modulation (FM) is hypothesized to indicate positive emotion; however, results from recent studies...