Introduction
In Germany, animal production represents more than 60% of the total value of agricultural output. As
in other Western countries, the focus is no longer on volume (or mass production?), but increasingly
on product quality and variety. According to recent estimates of the FAO, the world population will
increase to 8.3 billion by 2030. With the predicted increase in affluence, the demand for high quality
animal protein will increase significantly. In Asia, an increase by 40% is expected within the next
decade.
In order to meet the growing demands, it will be mandatory to further increase the efficiency of
production, while greenhouse gases from animal production have to be reduced in parallel. Under
European conditions farm animals will also play an increasing role in maintaining the landscape, for
leisure and sports as well as production for niche markets.
Animal breeders have to maintain genetic diversity as a reservoir for future adaptation of livestock
populations to changing goals and production needs. Modern breeding methods applied since the
second half of the 20th century, have changed populations of farm animals considerably. A small
number of highly productive breeds have become dominant at the expense of local breeds and survival
of some of these is now endangered. The distribution of high yielding and efficient breeding stock will
become even more global in the future. More and more traits are being included in selection programs
to develop farm animal populations for specific future needs.
Man’s association with farm animals dates back to pre-historic times. The characteristics of today’s farm
animals are the result of centuries of deliberate selection. More recently, sequencing and annotating
the genomes of farm animal species has contributed considerably to our understanding of the genetics
of farm animals, including cattle, pigs, poultry, horses, dogs and honey bees. New genetic tools not
only allow us to analyze genomic variation, but also to modify genotypes.
Combined with advances
in reproductive technologies, limitations of traditional breeding can now be overcome and new horizons
will be opened.
The German Society of Animal Breeding (DGfZ) has developed the following guidelines for future
animal breeding and farm animal research in Germany.
Application of molecular genetics in practical breeding:
The latest results from research on molecular genetics biotechnology should be combined with traditional methods of breeding and reproduction. Systematic analysis and detailed description of relevant traits using molecular genetics information is required to combine quantitative genetics with
modern tools for genomic selection. This is the only way to assure continued genetic progress of farm
animal populations. In cattle breeding genomic selection is already being practiced. Similar developments expected in other species will benefit from interdisciplinary research and development of
new methods.
Preservation of genetic diversity and avoidance of inbreeding:
Accumulating knowledge from genome analysis will add novel possibilities to describe genetic diversity and to increase diversity in farm animal populations. Improved biotechno-logical tools and computer
software as well as simplification of international exchange of genetic material (primordial germ cells,
embryos, semen, somatic cells) can contribute to maintenance and increase of genetic diversity. The
potential of these developments should be exploited in internationally competitive research and for
developing novel strategies in domestic animal
breeding and reproduction.
Molecular processes will become more important in applied breeding:
Animal farming is following the same path with regard to applied genomics as we have already seen
with humans and laboratory animals. With suitable array techniques it is already possible to describe
the expression of mRNA and/or proteins of organs or whole organ systems. On this basis it is possible
to gain a better understanding of interactions between genes and gene clusters as well as processes
within animals in response to given environmental conditions. Intensive inter-disciplinary and cooperative
research will be required, and the farm animal industry should be open and receptive for the
application
of results.
Understanding epigenetic effects will contribute to improved reproduction:
Genomic information and the high degree of epigenetic plasticity offer new possibilities to reduce
early embryonic mortality, to improve fertility and to shorten the generation interval by using prepuberal
animals. Research with embryonic development of farm animals, predominantly cattle, is increasingly
being used as model for human medicine, specifically for assisted reproductive technologies. Epigenetic
research with farm animals is still in its infancy, but results from model populations suggest that
epigenetics acts as bridge between genotype and environment and will thus become
more important
in explaining phenotypic observations in farm animal populations. The full exploitation of this potential
will require innovative research.
Transgenic animals will become more important:
It is already possible today, to produce farm animals with specific genetic changes by combining
molecular genetic tools with somatic cell nuclear transfer. Techniques which are being used in mice
to achieve a tightly regulated expression of genetic elements are increasingly being adapted to farm
animals. In addition to the use of transgenic animals for biomedical purposes, including gene pharming
and xenotransplantation, research will address possible application for agricultural purposes related
to efficiency, environmental impact and sustainability.
Potential application of research results has to
be validated, and potential risks and opportunities have to be communicated early with the public,
which is known for a strong bias against genetically modified organisms.
Farm animals as model for human disease:
Transgenic animals are increasingly being used as model to study human diseases and disorders
like mucoviscidosis, diabetes, different forms of cancer and diseases of the vasculatory system. This
is not limited to basic research, but may also involve pre-clinical testing. Genetically modified farm
animals will increasingly be used to test novel stem cell therapies. Research is needed to exploit
these new areas of development and to train young scientists for these challenges.
To realize these promising perspectives will require innovative interdisciplinary research with international
cooperation. To secure a sufficient supply of high quality animal protein for the growing world population
will require continued interdisciplinary research and introduction of science-based innovations in
practice. Highly qualified specialists need to be trained to respond to new challenges in animal breeding
and reproduction, farm management, nutrition and disease control.
The rapid development of molecular genetic tools requires the protection of intellectual property and
technical innovation, e.g. by patenting. However, progress in animal breeding should not be limited by
patents. It is up to patent courts, politics and administrations to find practical solutions which protect
new developments without hampering practical animal breeding and production.
In view of the global challenge to feeding the growing world population a return to traditional animal
farming is no realistic option. Research and animal industry are called upon to continue the road of innovation with due responsibility.
Zusammenfassung
Stellungnahme der Deutschen Gesellschaft für Züchtungskunde zur Zukunft
der Tierzucht und Tierzuchtforschung in Deutschland
Dr. Ernst-Jürgen Lode, Präsident der Deutschen Gesellschaft für Züchtungskunde (DGfZ) und Prof.
Dr. Heiner Niemann, Vorsitzender des Fachbeirats der DGfZ, haben Leitlinien für die künftige Tierzucht
und Tierzuchtforschung zu folgenden Themen vorgestellt:
• Übertragung molekulargenetischer Erkenntnisse in die praktische Tierzucht
• Genetische Vielfalt zum Erhalt genetischer Ressourcen und zur Vermeidung von Inzucht
• Zunehmende Bedeutung molekularer Prozesse und Einfluss auf die züchterische Arbeit
• Bedeutung epigenetischer Erkenntnisse für eine Steigerung der Fruchtbarkeit und Erklärung von
Umwelteinflüsse auf das Tier
• Künftige Bedeutung transgener Tiere
• Nutztiere als neues Modell für menschliche Erkrankungen
Einzelheiten sind dem Originalbeitrag im März/April-Heft 2009 der Züchtungskunde (82: 99-101) zu
entnehmen.