Congratulations to Dr. Michael Walker in Georgia Mason's lab for the highly commended paper described below
from site : https://www.nc3rs.org.uk/3rsprizewinners [1]

Highly Commended: Dr Michael Walker, University of Guelph

• Walker M, Fureix C, Palme R (2016). Mixed-strain housing for female C57BL/6, DBA/2, and BALB/c mice: validating a split-plot design that promotes refinement and reduction. BMC Medical Research Methodology 16:11 doi:10.1186/s12874-016-0113-7 [2]

The authors describe an alternative experimental design and analysis method – termed a ‘split-plot’ design – where animals are housed in mixed-strain groups. Female C57BL/6 (black), DBA/2 (brown) and BALB/c (white) mice were allocated to either enriched or standard treatments and screened for commonly measured and/ or welfare-relevant behavioural, physiological and haematological variables including corticosterone metabolite output and stereotypic behaviours. Results showed that living in mixed-strain trios did not reduce mouse welfare, or cause any change to strain-dependent or enrichment typical differences, validating it as an alternative study design.

The application of a ‘split-plot’ design meant fewer animals were required in each treatment group. The authors estimate, compared to a traditional design, this design can cut animal numbers required to achieve 80% power by more than half. Testing multiple strains increases the external validity of the experiment, thus increasing the generalisability of the results to other environmental contexts or populations.