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. 
Sánchez-Salcedo, J. A., Yáñez-Pizaña, A. 2024. Effects of free farrowing system on the productive performance and welfare of sows and piglets. Journal of Applied Animal Welfare Science 27(1), 1–11.

Regardless of international animal welfare regulations, most sows in production currently spend most of their lives and the peripartum period in caged housing systems. Although this type of management is intended to reduce neonatal mortality...

Dumniem, N., Boonprakob, R., Parsons, T. D. et al. 2023. Pen versus crate: A comparative study on the effects of different farrowing systems on farrowing performance, colostrum yield and piglet preweaning mortality in sows under tropical conditions. Animals 13(2), 233.

The present study was performed to determine the farrowing performance of sows, newborn piglet characteristics, colostrum yield, milk yield and piglet preweaning mortality in a free-farrowing pen compared to a conventional farrowing crate system in...

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)...

Kaiser, S., Korte, A., Wistuba, J. et al. 2023. Effects of castration and sterilization on baseline and response levels of cortisol—A case study in male guinea pigs. Frontiers in Veterinary Science 9, 1093157.

An uncontrolled reproduction of animals in human hands should be avoided. To meet this goal, animals are widely castrated, i.e., the gonads are completely removed. Since the gonads are the most important source of sex...

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...

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...

Andersen, I. L., Ocepek, M., Thingnes, S. L. et al. 2023. Welfare and performance of finishing pigs on commercial farms: Associations with group size, floor space per pig and feed type. Applied Animal Behaviour Science 265, 105979.

Based on data from a field survey of 85 Norwegian farms, we aimed to investigate associations of group size, floor space per pig and type of feed with selected welfare- and performance indicators in finishing...

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...

Hall, C. A., Potvin, D. A., Conroy, G. C. 2023. A new candling procedure for thick and opaque eggs and its application to avian conservation management. Zoo Biology 42(2), 296–307.

The ability to monitor developing avian embryos and their associated vascular system via candling enables the application of important reproductive management techniques. Egg candling facilitates the confirmation of egg viability throughout the incubation process and...

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...

Pierdon, M. K., Berdahl, S. E. 2023. Effect of topical spray containing lidocaine on piglet behaviour post castration. Journal of Applied Animal Welfare Science 26(2), 195–204.

Previous studies examining the impact of topical lidocaine spray on postcastration pain behavior in piglets used scan sampling for the collection of behavior data. This methodology led to inconclusive results on the efficacy of topical...

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...

Merlot, E., Meunier-Salaün, M.-C., Peuteman, B. et al. 2022. Improving maternal welfare during gestation has positive outcomes on neonatal survival and modulates offspring immune response in pigs. Physiology & Behavior 249, 113751.

Improving the housing of pregnant sows by giving them more space and access to deep straw had positive effects on their welfare, influenced their maternal behavior and improved the survival of their offspring. The present...

Spitzer, H. B., Meagher, R. K., Proudfoot, K. L. 2022. The impact of providing hiding spaces to farmed animals: A scoping review. PLOS ONE 17(11), e0277665.

Many wild animals perform hiding behaviours for a variety of reasons, such as evading predators or other conspecifics. Unlike their wild counterparts, farmed animals often live in relatively barren environments without the opportunity to hide...

Baxter, E. M., Moustsen, V. A., Goumon, S. et al. 2022. Transitioning from crates to free farrowing: A roadmap to navigate key decisions. Frontiers in Veterinary Science 9, 998192.

There are animal welfare concerns about the continued use of permanent crating systems for farrowing and lactating sows, which is the most prevalent maternity system in global pig production. Greater societal attention in recent years...

Chou, J.-Y., Parsons, T. D. 2022. A systematic review of the impact of housing on sow welfare during post-weaning and early pregnancy periods. Frontiers in Veterinary Science 9, 903822.

Breeder animals are an important focus in farm animal welfare assessments as they typically live the longest lives and are at the greatest risk for suffering due to their longevity. For breeding pigs, the time...

Mota-Rojas, D., Velarde, A., Marcet-Rius, M. et al. 2022. Analgesia during parturition in domestic animals: Perspectives and controversies on its use. Animals 12(19), 2686.

This article analyzes the physiological role of pain during parturition in domestic animals, discusses the controversies surrounding the use of opioids, non-steroidal anti-inflammatory drugs (NSAIDs), and local analgesics as treatments during labor, and presents the...

Schwarzer, A., Erhard, M., Schmidt, P. et al. 2022. Effects of stocking rate and environmental enrichment on the ontogeny of pecking behavior of laying hen pullets confined in aviary compartments during the first 4 weeks of life. Animals 12(19), 2639.

The objective of this study was to describe the ontogeny of the severe feather pecking (SFP), gentle feather pecking (GFP), aggressive pecking (AP), and enrichment pecking (EP) of non-beak-trimmed Lohmann Brown (LB)-pullets during the first...

van der Eijk, J. A. J., Gunnink, H., Melis, M. et al. 2022. Reducing stocking density benefits behaviour of fast- and slower-growing broilers. Applied Animal Behaviour Science 257, 105754.

The broiler industry has come under sustained pressure from welfare organizations to improve broiler welfare. Breed and stocking density are important factors for broiler welfare and are often specified as criteria for higher welfare systems...

Bilkó, Á., Petróczi, I., Bárdos, B. et al. 2022. Composition of the wild rabbit nest and its implication for domestic rabbit breeding. Applied Sciences 12(4), 1915.

Wild European rabbits (Oryctolagus cuniculus) give birth in an underground nursery burrow where the kits are hermetically closed into the nest chamber for several weeks except for the three minutes of daily nursing. Given this...

Phillips, H. N., Heins, B. J. 2021. Effects of outdoor stocking density on growth, feather damage and behavior of slow-growing free-range broilers. Animals 11(3), 688.

Access to pasture is a main benefit of free-range broiler housing systems, yet the level of outdoor stocking density on broiler animal welfare remains unsettled. The growth, feather damage, pasture ranging and behaviors were assessed...

Steybe, L., Kress, K., Schmucker, S. et al. 2021. Impact of housing condition on welfare and behavior of immunocastrated fattening pigs (Sus scrofa domestica). Animals 11(3), 618.

The aim of this study was to investigate whether the well-known positive effects of immunocastration on the behavior and welfare of pigs persist under varying environments. One hundred forty-four male pigs were studied with regard...

Roubos, S., Louwerse, A. L., Langermans, J. A. M. et al. 2021. Retrospective analysis of the effectiveness and reversibility of long-acting contraception Etonogestrel (Implanon®) in common marmosets (Callithrix jacchus). Animals 11(4), 963.

Contraception is an important population control method for the colony management of primates housed in captivity. Etonogestrel (ENG) implants (i.e., Implanon®) are a widely used progestin-based contraceptive in common marmosets (Callithrix jacchus) with the theoretical...

Kumar, V., Buragohain, S., Deka, P. J. et al. 2021. Non-invasive reproductive hormone monitoring in the endangered pygmy hog (Porcula salvania). Animals 11(5), 1324.

The pygmy hog (Porcula salvania), until recently was classified as a critically endangered suid facing the threat of extinction due to habitat degradation. Efforts are being made to protect the pygmy hog from extinction and...

Anderson, M. G., Campbell, A. M., Crump, A. et al. 2021. Effect of environmental complexity and stocking density on fear and anxiety in broiler chickens. Animals 11(8), 2383.

Barren housing and high stocking densities may contribute to negative affective states in broiler chickens, reducing their welfare. We investigated the effects of environmental complexity and stocking density on broilers’ attention bias (measure of anxiety)...