The 3R principle is the most important ethical guideline in preclinical research, which ensures that the number of animals used in research is kept to a minimum (reduction), if already possible experiments are replaced by alternative methods (replacement), and animal welfare in husbandry and experimental design is continuously improved (refinement).
Due to its importance, the 3Rs principle has now also found its way into the legislation of the European Union and its member states, e.g. within the Austrian Animal Experiments Act (TVG 2012). Thus, both universities and industry are obliged to base their research on this principle.
Here is a detailed list of the 3Rs:
Reduction: refers predominantly to the choice of an adapted study design, which, using appropriate experimental designs and statistical methods, requires the lowest possible number of animals without negatively affecting the gain of knowledge in the process. Further possibilities for reduction are optimized breeding strategies, archiving of unneeded lines, and the use of methods that maximize the information gain per animal (e.g. modern imaging methods such as positron emission tomography).
Replacement: The term replacement represents all methods that can be used to replace certain animal experiments or components of the experiment. The most common replacement methods can be found in the field of in vitro methods, such as animal-free cell cultures, or the modern organs-on-a-chip, which are able to imitate the function of organs or entire organ systems. Replacement also includes the so-called in-silico methods, i.e. methods that simulate physiological processes on the computer.
Refinement: On one hand, an improvement of animal welfare can be ensured by an appropriate experimental setup, e.g. by appropriately optimized anesthesia and analgesia protocols. On the other hand, stress, suffering and anxiety can also be minimized by improving the housing conditions, e.g. by offering additional behavioural enrichment, larger housing systems and appropriate training of the animals.
In addition to implementing the 3Rs principle in routine operations, the Core Facility Laboratory Animal Breeding and Husbandry also assists researchers in identifying potential approaches to the 3Rs principle in breeding, husbandry, and experimentation.
The Core Facility Laboratory Animal Breeding and Husbandry also represents one of the sites of the Austrian 3R Center, which was founded as a national knowledge platform for the 3Rs and is managed by the members of the RepRefRed Society.