
Animal experiments are necessary in order to understand biological principles and develop new therapeutic approaches for humans. However, scientists are obliged to replace animal experiments with alternatives as far as possible and to work towards the development of further alternative methods. Veterinarians, animal carers and researchers are constantly working to improve animal welfare both in experiments and in husbandry.
The 3R principles
Scientists at the DRFZ are very aware of their responsibility towards animals and always apply the 3R principle to experiments in order to reduce the stress on animals.. The 3Rs stand for ‘Replace, Reduce, Refine’. In practical terms, this means researchers at the DRFZ attempt to carry out as many experiments as possible without the use of animals (‘Reduce & Replace’), for example by using cell cultures. When carrying out animal experiments, care is taken to use a statistically calculated minimum group size of animals, with no more animals used than necessary (‘Reduce’). Moreover, due to the availability of more and more sophisticated technology, many non-invasive examination methods are available (‘Refine’), which reduce animal suffering and allow data to be generated from just a few animals (‘Reduce’).
Scientists are advised in their work by independent animal welfare officers, who also ensure and monitor the welfare of the animals and compliance with all guidelines and regulations. The Animal Welfare Committee, which meets regularly, supports the animal welfare officers in their work and in monitoring animal welfare.
Today, the 3Rs principle is the basis for animal welfare policy and practice and practice of modern research approaches in many countries.This animated film explains the 3R principle and describes how it is implement-ed in research.
(Source: https://www.tierversuche-verstehen.de/filme/)
Alternative methods
According to the Animal Welfare Law, animal experiments may only be carried out if no animal-free methods are available (Animal Welfare Law § 7a Para. 2 No. 2). Animal experiments are still the only way to find out which circumstances cause the immune system to react against the body.
Understanding animal testing – a science information initiativeResearchers are obliged to use alternative methods whenever possible. This animated film provides a clear overview of this topic.
(Source: https://www.tierversuche-verstehen.de/filme/)
Whenever possible, we use alternative methods to replace animal experiments or reduce the number of animals. For example, early-career scientists learn how to take blood samples and give injections using an alternative mouse model.
Did you know: At the DRFZ, we are also working on the development of alternative methods to replace certain animal experiments in the future. For example, Dr Timo Gaber, from the Buttgereit research group, is working together with Dr Alexandra Damerau and Dr Moritz Pfeiffenberger on the development of vitro 3D models that simulate inflamed joints.
Handling & Habituation
From birth, mice are habituated to handling using gentle methods. One of the methods used for this is tunnel handling. For this purpose, there is a transparent tunnel in the cage, which serves as a hiding place for the mice and represents a familiar environment. The animal can be taken out of the cage via the tunnel to carry out a health check, for example. Several studies have shown that this type of handling is significantly less stressful for the animals than lifting them by the tail. It has also been shown that working with less stressful animals has a positive effect on scientific results and that the data obtained is more reliable and reproducible.

At the DRFZ, no experiment takes place without the mouse first being made familiar with the researchers and the method to be used. We take the time to habituate each individual animal to the experimental situation as part of a preparatory habituation programme. After a few days of the habituation programme, the animals are much more calm.
Take a closer look at how the animals’ habituation programme is designed in our short video.
Animals’ habituation programme
Film: Theres Manthey, Jacqueline Hirscher
Music: Moviemaker from Apple
Youtube: DRFZ-Channel
Enrichment
In order to allow the animals to act out their natural exploratory behaviour, we have equipped large rat cages with all kinds of equipment in which the animals can explore various activities after the preparatory habituation programme. The mice reacted to the so-called playgrounds with great curiosity and enthusiasm during the test run, so we decided to offer them this opportunity for exploratory behaviour in general and are now gradually replacing the standard housing cages with large cages with more enrichment.

The Animal Welfare Committee
The animal welfare officers at the DRFZ are supported in the fulfilment of their tasks by the Animal Welfare Committee, which meets regularly. At the meetings, projects and their results are reviewed and discussed, internal work processes are defined and new refinement options for scientific studies, as well as breeding and husbandry, are decided in order to further improve animal welfare.
The Animal Welfare Committee at the DRFZ is made up of veterinarians, animal care staff and scientific and technical personnel.