Well-managed laboratory animal colonies minimize animal numbers while maintaining scientific validity, and good colony management practices are essential for both welfare and research quality.
Colony management is where the Reduction principle of the 3Rs either succeeds or fails in practice. Poor planning leads to chronic overproduction of animals — surplus mice and rats are killed without contributing to any experiment. This represents welfare harm without scientific benefit. Conversely, inadequate planning leads to experimental delays that result in repeated experiments using more animals than necessary. Good colony management requires skilled personnel, appropriate software systems, and institutional commitment to reducing waste. Cryopreservation of genetic lines that are not in active use avoids maintaining large populations of animals in holding conditions indefinitely. The welfare dividend from improved colony management is substantial: fewer animals produced means fewer animals experiencing the stresses of laboratory housing.