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...

Silva-Almeida, C., Muniz, S. C. A., Jobim, C. M. N. et al. 2024. Perinatal environmental enrichment changes anxiety-like behaviours in mice and produces similar intergenerational benefits in offspring. Behavioural Brain Research 456, 114700.

Environmental enrichment implemented in early life is able to induce long-term changes in gene expression, synaptic function and behavioural responses. In this study, we evaluated the adult behavioural effects of perinatal environment enrichment in male...

Wang, Q., Wang, Y., Tian, Y. et al. 2024. Social environment enrichment alleviates anxiety-like behavior in mice: Involvement of the dopamine system. Behavioural Brain Research 456, 114687.

Rearing environment plays a vital role in maintaining physical and mental health of both animals and humans. Plenty of studies have proved that physical environment enrichment in adolescence has protective effects on emotion, social behavior...

Hube, D., Bill, J., Knop, E. S. et al. 2023. Physical injuries and hair corticosterone concentration in rabbit kits from single- and group-housed does kept on a commercial farm. Animals 13(2), 196.

In intense breeding programs, rabbits are exposed to numerous stress factors which could affect their welfare and health. It has been suggested that group housing is more comfortable for does and similar to the living...

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...

Harauma, A., Murai, M., Nakamura, I. et al. 2023. Anxiety-like behaviors in artificially reared mice is reduced by contact with foster mothers. Physiology & Behavior 260, 114052.

Experimental systems using animal models are important for nutritional and pharmacological research on newborns and infants. Accordingly, artificial nursing systems for rodents based exclusively on formula are critical to studying nutrient requirements, chemical safety, and...

Cho, E., Walsh, C. A., D’Angelo-Gavrish, N. M. et al. 2023. Effects of housing density on reproductive performance, intracage ammonia, and welfare of mice continuously housed as breeders in standard mouse and rat caging. JAALAS 62(2), 116–122.

Maintaining compliance with cage density recommendations in The Guide for the Care and Use of Laboratory Animals precludes continuous trio breeding in standard-sized mouse cages. This study evaluated and compared several parameters of reproductive performance...

Scariot, P. P., Gobatto, C. A., Polisel, E. E. et al. 2022. Early-life mice housed in standard stocking density reduce the spontaneous physical activity and increase visceral fat deposition before reaching adulthood. Laboratory Animals 56(4), 344-355.

Laboratory rodents spend the entire day housed in standard cages that provide a restricted area for movements and might, therefore, limit physical activity. However, it has not been tested in immature rodents of ages ranging...

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”)...

Anderson, M. G., Campbell, A. M., Kuhn, D. D. et al. 2022. Impact of environmental complexity and stocking density on affective states of rainbow trout (Oncorhynchus mykiss). Animal Cognition 25(5), 1331–1343.

Environmental condition, such as environmental complexity or stocking density, can directly or indirectly influence animal emotion and ultimately, affective state. Affective states of animals can be assessed through judgement bias tests, evaluating responses to ambiguous...

Brogan, E., Kirchain, S. 2021. When to wean? A visual guide to Black, White, and Agouti mouse pup growth P14 – P28. Laboratory Animal Science Professional 9(3) (May/June), 46-48.

Laboratory mouse pups are commonly weaned between postnatal day 21–28. Utilization of an exact wean date postpartum is a concrete metric for mouse colony management, but variation can result such as: developmental differences among genetically...

Ratuski, A. S., Weary, D. M. 2021. A break from the pups: The effects of loft access on the welfare of lactating laboratory rats. PLOS ONE 16(6), e0253020.

Rats (Rattus norvegicus) bred for research are typically confined with their litters until weaning, but will spend time away from pups when given the opportunity. We aimed to assess how dam welfare is affected by...

Brajon, S., Morello, G. M., Capas-Peneda, S. et al. 2021. All the pups we cannot see: Cannibalism masks perinatal death in laboratory mouse breeding but infanticide is rare. Animals 11(8), 2327.

Perinatal mortality is a major issue in laboratory mouse breeding. We compared a counting method using daily checks (DAILY_CHECK) with a method combining daily checks with detailed video analyses to detect cannibalisms (VIDEO_TRACK) for estimating...

Grims, C., Jacobson, C., Hedenqvist, P. 2021. Are female mice dehydrated during peak lactation? Effect of water and gel supplement on hydration parameters and water consumption in two strains of mice. Scandinavian Journal of Laboratory Animal Science 47(3), 16-24.

Mice (Mus musculus) have a high basal rate of metabolism which increases during pregnancy and lactation. During peak lactation, water intake amounts to up to 65 % of the bodyweight per day. Providing water in...

Rossi, M. J., de Oliveira Fermoseli, A. F., Hirano, Z. M. B. et al. 2020. Adoption of an orphaned and temporarily captive infant by an unrelated adult female in black-and-gold howler monkey: Implications for management strategies. Primates 61(2), 169–174.

Conservation behavior involves the application of general principles of animal behavior for solving conservation problems. In primates, adoption of infants has been reported in several species and consists of an individual other than the biological...

Araújo Tavares, G., Cavalcanti do Amaral Almeida, L., Araújo de Souza, J. et al. 2020. Early weaning disrupts feeding patterns in female juvenile rats through 5HT-system modulations. Behavioural Processes 170, 103981.

Convergent evidence in literature shows that rapid disruption of maternal care and breastfeeding due to an early weaning protocol changes the development of several neurobehavioral patterns in rodents, including the circadian pattern of feeding. The...

Morello, G. M., Hultgren, J., Capas-Peneda, S. et al. 2020. High laboratory mouse pre-weaning mortality associated with litter overlap, advanced dam age, small and large litters. PLOS ONE 15(8): e0236290.

High and variable pre-weaning mortality is a persistent problem in laboratory mouse breeding. Assuming a modest 15% mortality rate across mouse strains, means that approximately 1 million more pups are produced yearly in the EU...

Bailoo, J. D., Voelkl, B., Varholick, J. et al. 2020. Effects of weaning age and housing conditions on phenotypic differences in mice. Scientific Reports 10, 11684.

Poor reproducibility is considered a serious problem in laboratory animal research, with important scientific, economic, and ethical implications. One possible source of conflicting findings in laboratory animal research are environmental differences between animal facilities combined...

Dewaele, A., Badonnel, K., Persuy, M.-A. et al. 2020. Effect of environmental exposure to a maternally-learned odorant on anxiety-like behaviors at weaning in mice. Animal Cognition 23(5), 881–891.

Early sensory experience, such as exposure to maternal or other environmental factors, is considered to influence neurocognitive development and behaviors. In many species, exposure to odorants during pregnancy or lactation impacts the morpho-functional development of...

Brajon, S., Morello, G. M., Teixeira, M. S. et al. 2019. Social environment as a cause of litter loss in laboratory mouse: A behavioural study. Applied Animal Behaviour Science 218, 104827.

Perinatal mortality is a widespread problem in laboratory mouse breeding and is often manifested by the loss of the entire litter within the first days of life. High mortality is an animal health and welfare...

Leidinger, C. S., Thöne-Reineke, C., Baumgart, N. et al. 2019. Environmental enrichment prevents pup mortality in laboratory mice. Laboratory Animals 53(1), 53–62.

Early death of mouse pups is a commonly known problem in breeding mice colonies, which is still often regarded as ‘normal’ or is even overlooked due to the counting procedures applied. As reduced breeding performance...

Bailoo, J. D., Murphy, E., Varholick, J. A. et al. 2018. Evaluation of the effects of space allowance on measures of animal welfare in laboratory mice. Scientific Reports 8, 713.

We studied how space allowance affects measures of animal welfare in mice by systematically varying group size and cage type across three levels each in both males and females of two strains of mice (C57BL/6ByJ...

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...