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. 
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...

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...

Crawford, C., Rand, J., Rohlf, V. et al. 2023. Solutions-based approach to urban cat management—Case studies of a One Welfare approach to urban cat management. Animals 13(21), 3423.

Urban free-roaming cats create concern about their impacts on wildlife and human health, leading to the use of trap–adopt–kill methods to manage these populations. This method is ineffective at decreasing the free-roaming cat population and...

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...

Piekarski, N., Hobbs, T. R., Jacob, D. et al. 2023. A comparison of oocyte yield between ultrasound-guided and laparoscopic oocyte retrieval in rhesus macaques. Animals 13(19), 3017.

Obtaining quality oocytes is a prerequisite for ART-based studies. Here we describe a method for transabdominal ultrasound-guided (US) oocyte retrieval in rhesus macaques (Macaca mullata) and compare it to the standard surgical approach using laparoscopy...

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...

Karaskiewicz, C. L., Ramirez, M., Bales, K. L. 2023. Physiological and behavioral effects of hormonal contraceptive treatment in captive, pair-bonded primates (Plecturocebus cupreus). JAALAS 62(6), 494–501.

Hormonal contraception is an effective, reversible tool for managing birth rates in humans and nonhuman animals alike. However, manipulating reproductive hormones has behavioral consequences that can impact social and sexual behavior between conspecifics. First, we...

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...

Rosales, C., Sands, C. 2022. Confirming sexual maturity in male cynomolgus macaques by urinary spermatozoa microscopic examination. Laboratory Animal Science Professional 10(1) (January/February), 60-61.

Medications often require studies performed in sexually mature cynomolgus macaques. At this time, there are few options available to confirm sexual maturity in male macaques. Electroejaculation and collection of seminal fluid are invasive and require...

Schnaider, M. A., Heidemann, M. S., Silva, A. H. P. et al. 2022. Cat vocalization in aversive and pleasant situations. Journal of Veterinary Behavior 55-56, 71-78.

Vocalization may transmit information from the emitting animal, including information about his or her emotional state. This study aimed to compare the vocal and the behavioral responses of domestic cats during an aversive and a...

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...

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...

Ginovart-Panisello, G. J., Iriondo Sanz, I., Panisello Monjo, T. et al. 2022. Trend and representativeness of acoustic features of broiler chicken vocalisations related to CO2. Applied Sciences 12(20), 10480.

The concentration of CO2 is relatively large in poultry farms and high accumulations of this gas reduce animal welfare. Good control of its concentration is crucial for the health of the animals. The vocalizations of...

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...

McDonald, M. M., Agnew, M. K., Asa, C. S. et al. 2021. Melengestrol acetate contraceptive implant use in colobus monkeys (Colobus guereza): Patterns through time and differences in reproductive potential and live births. Zoo Biology 40(2), 124-134.

Melengestrol acetate (MGA) implants are progestin-based reversible contraceptives used to manage fertility in zoo populations. Although it is recommended that MGA implants should be replaced every 2 years, the duration of efficacy has not been...

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)...

Forslind, S., Blokhuis, H. J., Riber, A. B. 2021. Disturbance of resting behaviour of broilers under different environmental conditions. Applied Animal Behaviour Science 242, 105425.

Resting behaviours make up a large part of the daily time budget of broilers. However, in intensive broiler production systems disruptions of resting behaviours occur, where resting individuals get disturbed by active individuals. Such interruptions...

Penfold, L. M., Norton, T., Asa, C. S. 2021. Effects of GnRH agonists on testosterone and testosterone-stimulated parameters for contraception and aggression reduction in male lion-tailed Macaques (Macaca silenus). Zoo Biology 40(6), 541-550.

Managing social groups in zoos requires controlling reproduction in individuals that do not have a current breeding recommendation, while simultaneously maintaining social harmony and animal well-being. Contraceptives, such as gonadotropin releasing-hormone (GnRH) agonists, that suppress...

van den Oever, A. C. M., Rodenburg, T. B., Bolhuis, J. E. et al. 2020. Relative preference for wooden nests affects nesting behaviour of broiler breeders. Applied Animal Behaviour Science 222, 104883.

Optimising nest design for broiler breeders has benefits for both the animals and the producers. The welfare of the hens will increase by providing preferred housing, while also reducing eggs laid outside the nests. These...

Reinhardt, V. (ed.) 2020. It’s Okay to Cry - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume V. Animal Welfare Institute, Washington, DC.

This is the 5th volume of selected discussions that took place on the electronic Laboratory Animal Refinement & Enrichment Forum between February 2016 and December 2019. The forum was created in October 2002; it allows...

Gebhardt-Henrich, S. G., Jordan, A., Toscano, M. J. et al. 2020. The effect of perches and aviary tiers on the mating behaviour of two hybrids of broiler breeders. Applied Animal Behaviour Science 233, 105145.

Broiler breeders are kept for the production of fertile eggs. They face serious welfare problems like aggressive behaviour of the males towards females during mating. Furthermore, broiler breeders are usually kept without perches which are...