Replacement means that animal experiment free alternative must be used where possible. In case it is necessary to work with animals, one should use the lowest evolved species possible. This way, for example, pigs will never be used when it is possible to perform a study in mice.
Reduction will make sure the lowest number of animals is used while still sufficient in order to obtain statistically relevant results.
Refinement aims to improve the welfare of the animals. This can, for example, be done by using pain medication and anaesthesia for surgical procedures, enrichment of the cages (e.g. gnawing cubes, nesting material, adjusted bedding material) but also by housing conditions (e.g. group housing of social animals) and by means of humane endpoints.
At Hasselt university, we also value a 4th R, namely Responsibility. Each researcher and animal caretaker has to take his or her responsibility in order to guarantee animal welfare by means of good caretaking and treatment of the animals. In addition, we also have an animal welfare body that stands by to provide advice. In case (welfare) problems occur, the animal welfare body will investigate how the problems arose, how they can be solved and how they can be prevented in the future.