Researchers have both a moral and a legal obligation to seek out and use alternatives to laboratory animals wherever possible. As far as the law is concerned, use of alternatives – the 3Rs – is the corner stone of the EU directive on protection of animals used for scientific purposes.
The directive’s protection covers not only fully developed animals from birth or hatching, but also animals at earlier stages of development – including mammal foetuses. Mammal foetuses are always protected from the start of the final third of their normal development, but are also protected at earlier developmental stages if they are to remain alive and are expected to experience pain, suffering, distress or lasting harm as a result of experimental procedures. Attention must also be given to the way mammal fosters are killed, as humane killing methods are required for all animals covered by the directive.
The difference between the calf foetus used as a source of serum and the calf foetus used in the laboratory is, that the foetus in the laboratory is protected by the EU directive, whereas the foetus from which blood is taken at the slaughterhouse for use in serum production is covered by slaughter legislation, which does not take account of the living calf foetus. Therefore the foetal calf at the slaughterhouse may suffer while the foetal calf in the laboratory may not.
Replacement of foetal calf serum with a non-animal nutrient medium is part of the practical implementation of the 3Rs.