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. 
Wang, C., Han, Q., Liu, R. et al. 2020. Equipping farrowing pens with straw improves maternal behavior and physiology of Min-Pig hybrid sows. Animals 10(1), 105.

This study investigated the effects of two factors, enriched environment (EE) and different crossbreeds, on the maternal behavior and physiology of Min-pig hybrid sows. The analysis was performed on a total of 72 multiparous sows...

Zhang, X., Li, C., Hao, Y. et al. 2020. Effects of different farrowing environments on the behavior of sows and piglets. Animals 10(2), 320.

We investigated the effect of different farrowing systems on the behavior of sows and piglets. In total, 22 hybrid sows (Yorkshire × Landrace) were randomly assigned into three farrowing systems, farrowing crate (FC), free farrowing...

Chou, J.-Y., D’Eath, R. B., Sandercock, D. A. et al. 2020. Enrichment use in finishing pigs and its relationship with damaging behaviours: Comparing three wood species and a rubber floor toy. Applied Animal Behaviour Science 224, 104944.

Environmental enrichment in pig housing is a legal requirement under current EU legislation, but some recommended loose materials may cause obstructions in fully-slatted systems. Wood is an organic material that could be compatible with slatted...

de la Garza, F., Cannon, C. Z. 2020. Piggy see, piggy do: A swine training program enhances animal welfare and research. Laboratory Animal Science Professional 8(2) (March/April), 54-57.

Becton Dickinson (BD) Animal Research Program developed an extensive training and environmental enrichment program to acclimate newly arrived swine to daily husbandry routines. The program seeks to build trust between swine and animal care and...

Luo, L., Jansen, C. A., Bolhuis, J. E. et al. 2020. Early and later life environmental enrichment affect specific antibody responses and blood leukocyte subpopulations in pigs. Physiology & Behavior 217, 112799.

This study addressed the impact of early and later life environmental enrichment, and their combination, on specific antibody responses and peripheral blood leukocyte subpopulations in pigs. Pigs were kept in either barren (B1) or enriched...

Crawford, L. E., Knouse, L. E., Kent, M. et al. 2020. Enriched environment exposure accelerates rodent driving skills. Behavioural Brain Research 378, 112309.

Although rarely used, long-term behavioral training protocols provide opportunities to shape complex skills in rodent laboratory investigations that incorporate cognitive, motor, visuospatial and temporal functions to achieve desired goals. In the current study, following preliminary...

Qu, C., Xu, L., Shen, J. et al. 2020. Protection of blood-brain barrier as a potential mechanism for enriched environments to improve cognitive impairment caused by chronic cerebral hypoperfusion. Behavioural Brain Research 379, 112385.

Chronic cerebral hypoperfusion (CCH) is a common pathophysiological basis for Alzheimer’s Disease and vascular dementia in the early stages. It has been confirmed that blood-brain barrier (BBB) destruction is a key factor in CCH-related cognitive...

Menezes, J., Souto das Neves, B.-H., Gonçalves, R. et al. 2020. Maternal deprivation impairs memory and cognitive flexibility, effect that is avoided by environmental enrichment. Behavioural Brain Research 381, 112468.

Maternal deprivation (MD) causes cognitive deficits that persist until adulthood. Thereby, the environmental enrichment (EE) is widely used to increase brain plasticity. Here, pregnant female rats were used and their offspring were submitted to neonatal...

Ballantine, A., Rodgers, D., Watts, C. et al. 2020. The cotton rat – a new challenge. Animal Technology and Welfare 19(1), 92-95.

This poster describes how the Animal Technologists at Envigo adapted their current practices and procedures for a new species at their laboratory: the cotton rat. The paper describes cotton rat biology and behaviour; housing; environmental...

Kauselmann, K., Krause, E. T., Glitz, B. et al. 2020. Short-term choice of fattening pigs for additional plant-based materials. Applied Animal Behaviour Science 226, 104975.

A major problem in conventional pig production systems is the occurrence of abnormal behaviours such as tail biting. Tail biting is a multifactorial problem, but it seems that a lack of proper enrichment materials prevents...

Brekke, J., Scholz, J. 2020. Just hanging out: Elevating rat enrichment in small spaces. Laboratory Animal Science Professional 8(3) (May/June), 40-42.

This article describes how an Animal Care Technician at Mayo Clinic Rochester campus designed and created a novel enrichment item for rats: a ‘hammock’ made of PVC tunnels hung onto the lid of standard laboratory...

Matrai, E., Ng, A. K. W., Chan, M. M. H. et al. 2020. Testing use of a potential cognitive enrichment device by an Indo‐Pacific bottlenose dolphin (Tursiops aduncus). Zoo Biology 39(3), 156–167.

Cognitive enrichment aims to provide animals with opportunities to use their cognitive skills and to promote behaviors associated with positive wellbeing. Cooperation in mammals has been recorded during various behavioral contexts such as hunting, mating...

Luo, L., Reimert, I., Middelkoop, A. et al. 2020. Effects of early and current environmental enrichment on behavior and growth in pigs. Frontiers in Veterinary Science 7, 268.

Enriched environments are known to beneficially affect the behavior of pigs, as compared with barren pens. The influence of enrichment may, however, depend on pigs' early life housing experiences. The aim of this study was...

Parois, S. P., Duttlinger, A. W., Richert, B. T. et al. 2020. Effects of three distinct 2-week long diet strategies after transport on weaned pigs' short and long-term welfare markers, behaviors, and microbiota. Frontiers in Veterinary Science 7, 140.

Alternative feed supplements have shown promising effects in terms of performance, but their effects on welfare have had little evaluation. In the present study, we aimed at evaluating the effect of diet supplementation on welfare...

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...

Stevens, C., Finnegan, E., Clarkson, J. et al. 2020. Report of the 2019 RSPCA/UFAW Rodent Welfare meeting. Animal Technology and Welfare 19(2), 101-111.

The RSPCA/UFAW Rodent Welfare Group has held a one-day meeting every autumn for the last 26 years, so that its members can discuss current welfare research, exchange views on welfare issues, and share experiences of...

Blackburn, N., Cronshaw, G., Mitchell, M. 2020. Environmental enrichment for a small colony of rats. Animal Technology and Welfare 19(2), 158.

Due to limited space and resource for equipment, we came up with some easy and cost-effective ways to improve enrichment for the rat colony. Since implementing our protocol for forage feeding and out of cage...

Lauderdale, L. K., Miller, L. J. 2020. Efficacy of an interactive apparatus as environmental enrichment for common bottlenose dolphins (Tursiops truncatus). Animal Welfare 29(4), 379-386.

Environmental enrichment is a key component in improving the psychological and physiological well-being of animals under professional care. Environmental enrichment involves the addition of stimuli, including objects and cognitive challenges, into the environment in order...

Khoo, S. Y.-S., Correia, V., Uhrig, A. 2020. Nesting material enrichment reduces severity of overgrooming-related self-injury in individually housed rats. Laboratory Animals 54(6), 546-558.

Individual or singly-housing laboratory rats is common in many animal facilities, but has an adverse impact on the welfare of this social species. It has previously been shown that a small proportion of individually housed...

Chou, J., O’Driscoll, K., Sandercock, D. A. et al. 2020. Can increased dietary fibre level and a single enrichment device reduce the risk of tail biting in undocked growing-finishing pigs in fully slatted systems? PLOS ONE 15(10), e0241619.

This study evaluated the effectiveness of combined dietary and enrichment strategies to manage tail biting in pigs with intact tails in a conventional fully-slatted floor housing system. A 2 × 2 × 2 factorial design...

Gabriel, P., Mastracchio, T., Bordner, K. et al. 2020. Impact of enriched environment during adolescence on adult social behavior, hippocampal synaptic density and dopamine D2 receptor expression in rats. Physiology & Behavior, 226, 113133.

Environmental enrichment (EE) is one experimental manipulation that induces changes in the brain. However, it is important to distinguish between physical and social components of enrichment. To this end we established four groups of rats...

Keymoradzadeh, A., Hedayati Ch, M., Abedinzade, M. et al. 2020. Enriched environment effect on lipopolysaccharide-induced spatial learning, memory impairment and hippocampal inflammatory cytokine levels in male rats. Behavioural Brain Research 394, 112814.

Neuro-inflammation is responsible for cognitive impairments and neurodegenerative diseases such as Alzheimer’s disease. In this study, we aimed to investigate the enriched environment (EE) effect on learning and memory impairment as well as on pro-inflammatory...

Ko, H., Chong, Q., Escribano, D. et al. 2020. Pre-weaning socialization and environmental enrichment affect life-long response to regrouping in commercially-reared pigs. Applied Animal Behaviour Science 229, 105044.

Weaning and other regrouping events as routine work in commercial farms cause stress to pigs and compromise their welfare. Several studies found positive outcomes to mitigate weaning stress when piglets were socialized (i.e. co-mingled) or...

Kobek-Kjeldager, C., Moustsen, V. A., Theil, P. K. et al. 2020. Effect of litter size, milk replacer and housing on behaviour and welfare related to sibling competition in litters from hyper-prolific sows. Applied Animal Behaviour Science 230, 105032.

Litter sizes where piglets are supernumerary to teats leads to the practice of fostering to nurse sows or to artificial rearing systems, which is associated with compromised welfare. An alternative strategy is to leave the...

Lang, G. P. S. A., Rose, P. E., Nash, S. M. et al. 2020. The nocturnal activity of a commonly housed rodent: How African pygmy dormice (Graphiurus murinus) respond to an enriched environment? Journal of Veterinary Behavior 38, 82-88.

Exotic rodents are becoming increasingly popular in industry; however, there is limited empirical evidence to guide husbandry practices. African pygmy dormice (Graphiurus murinus) are typical in this respect. This research aimed to determine the effect...