What does the future of animal production hold? David Hume looks forward.
We need to plan for increased production of animal products.
And there is increasing recognition that protein malnutrition has long-term effects on development of cognitive ability. Vegetarianism is not an option; there is evidence of subclinical malnutrition on vegetarian diets even in Western countries, and in developing countries high quality vegetable protein sources are no more available than animal protein.
The challenge will be to meet this demand for animal products whilst at the same time reducing the overall environmental impact.
Everything that we eat is a genetically-selected organism that would not exist in its current form but for human intervention. Much of what we eat is already genetically-modified in that the mutations that produced desirable traits were artificially induced using radiation or chemicals prior to selection. The fact that everything we eat is a product of human intervention is as true for animals as it is for plants, even though intensive selection of animal breeds is a relatively modern phenomenon.
There have been massive increases in productivity in the livestock sector in the past 40 years. These gains have been achieved through a combination of genetic improvement and better husbandry, nutrition and disease control. The dairy, swine and poultry sectors are highly structured with a small number of international companies controlling large proportions of breeding and production. In contrast, the sheep, goat and beef cattle sectors are less highly structured and for these species together with others (e.g. buffalo, deer, llama, alpaca, camel) there remains considerable scope for improvements in productivity.
Furthermore, compared to land-based agriculture, we are at early stage in fish domestication, and substantial productivity and feed efficiency gains are clearly possible.
Improved efficiency of animals will involve continued selection, based upon genome-wide selection and high density genetic markers. Advances in systems biology, and knowledge from analysis of genotype-phenotype relationships will make such selection more predictive. In all major livestock, cloning of productive animals is available and already cost-effective, although the legal and ethical issues in Europe have yet to be resolved.
Nevertheless, it is very unlikely that existing genetic variation in animals will continue to generate the rate of gain in size or offspring number, for example, obtained in the past. A different kind of genetically-modified animal will be required.
Transgenesis [genetic engineering] to produce desired traits is possible and could provide clear benefits to the consumer in terms of cost, health, animal welfare and environment if regulatory requirements were based upon science rather than assertion. The first vanguard of genetically-modified animals, the Aquabounty salmon, has almost made its way through the regulatory hurdles in the US. As in plants, the immediate need is to protect against catastrophic pathogens such as avian influenza or African swine fever.
An alternative to transgenesis is the new genome editing technologies, which produce precise genetic changes without any residual insertion of foreign genetic material. One can reasonably argue that genome editing is identical to natural or induced random mutations in molecular terms and is considerably less likely to produce unforeseen consequences than the shotgun approach of selective breeding.
Bet the future farm
The future of livestock farming will undoubtedly involve further intensification. A greater understanding of the underlying mechanisms regulating behaviour in animals is essential to fully address the welfare issues associated with this change.
There is also a pressing need for the development of objective measures of stress in animals. There are ethical and economic arguments for improving the environments in which animals are kept rather than selecting genotypes. However, it is worth remembering that selection for behaviours such as docility and herdability has already occurred, and was essential to the domestication of animals.
What will constrain future advances in livestock production is investment. Large animal research is expensive. Over the past 20 years, there has been systematic underinvestment in the sector by governments all over the world, and expertise and infrastructure has declined. International development agencies and funders have placed disproportionate emphasis on crop research.
Livestock improvement is not a sector that can be left to industry. The applications of genomic selection require accurate performance measurements on very large numbers of animals. The profit margins for farming livestock at the individual farmer (or animal) level are small. Even in the poultry and pig breeding industries, where there is consolidation of the sector, the global players are dwarves compared to pharmaceutical or seed companies.
Sustainable gains in productivity of livestock can be achieved within the next 20 years. But they will only be achieved if governments recognise that the required research is “public good”, and re-enter and re-engage with the livestock research sector with substantial investment.
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About David Hume
Professor David Hume FSB, FMedSci, FRSE is the Director of The Roslin Institute, which is linked in the minds of many with a famous sheep. Since it joined the University of Edinburgh in 2008, and moved to a new research building in 2011, it has grown to well over 450 staff and students, and can make a reasonable claim to be the world’s leading animal sciences research institute.
Hume is an Australian but has worked all over the world. His main area of interest is the molecular basis of disease resistance and susceptibility with a particular focus on the function of specialised cells of the immune system in infection, inflammatory disease and cancer.