'Genetic variation is crucial for maintaining any population, but also for improving animal populations', says Prof. Dr. Mario Calus in his inaugural address as professor and chair of the Animal Breeding and Genomics Group at Wageningen University & Research on May 2. 'Use it but don't lose it', reads Calus' central message: the crucial balance between exploiting and preserving genetic diversity.
In his vision of the future of livestock farming, Calus stresses that changing societal desires also place new demands on animals. 'Animal friendly livestock farming requires animals that are sociable, cope well with stress, have high resistance and digest fibre-rich feed efficiently. All these traits are partly heritable, and therefore can be changed through breeding'.
Future-oriented livestock farming
Adding new traits to breeding goals, such as the ability to cope with the changing climate or animal welfare, also changes the genetic makeup of future generations. 'Again: use it, but don't lose it. Without sufficient genetic variation, there is nothing left to select in the long run'.
Genetic selection started about 10 thousand years ago with the domestication of animals. Selection is essential to improve desirable traits, such as fertility, health or feed efficiency.
Genomics as a powerful tool
Thanks to modern (computer) techniques such as genomic prediction, researchers can now determine much more precisely which animals have the best genetic predisposition. Yet, according to Calus, this is not a licence for unrestrained selection. The balance between genetic progress and maintaining diversity is crucial, and complex.
'In our field, we use the model P = G + E: the phenotype is the sum of genetics and environment,' Calus explains. 'But in reality, interactions between animals, the microbiome, and even epigenetic factors also play a role. It is precisely this complexity that makes our work challenging and socially relevant'.
A moral responsibility
'If we keep selecting the same animals as parents of the next generation, we lose genetic diversity', warns Calus. 'And that makes populations more vulnerable to disease, changing environments and unexpected challenges'.
Therefore, Calus finally stresses the ethical side of his work: 'For various reasons, we have lived together with animals for centuries. That brings responsibility: we have a duty to safeguard their genetic health and future - for themselves and for future generations of humans and animals'.
