Although genetics may not be obviously connected with agricultural sustainability, genetic improvement programs have dramatically decreased the environmental footprint of animal protein production in many parts of the world, and continued innovation is required to address the projected global increase in the demand for animal products in the future.
For example, the 8-week old body weight of broiler (meat) chickens has increased from 0.81 kg to 3.14 kg over the period 1957 to 2001, and approximately 80% of this four-fold increase has been the result of genetic selection. If not for this four-fold increase, we would need four times as many chickens to provide the same amount of animal product. Given poultry is by FAR the most numerous animal species consumed on the planet, as illustrated in Figure 1, imagine how many more food animals would be needed if not for the genetic improvements enabled by animal breeders.
Figure 1: Food for thought | National geographic by Nigel Holmes
It has been estimated that historic genetic improvement in selected livestock production traits (e.g. milk/meat output, feed efficiency) has resulted in an annual 1% reduction in GHG emissions per unit of animal product produced.
Some argue that we should just stop eating animal protein altogether. However, the projections of demand for animal protein in the developing world are compelling. Additionally, seeing animals only as food ignores the many other roles they play in society. These include that livestock:
• Contribute 40% of global value of agricultural output
• Support livelihoods and food security of almost 1 billion people
• Provide food and incomes and consume non-human edible food
• Contribute 15% of total food energy and 25% of dietary protein • Provide essential micronutrients (e.g. iron, calcium) that are more readily available in meat, milk, and eggs than in plant-based foods
• Are a valuable asset, serving as a store of wealth, collateral for credit, and an essential safety net during times of crisis
• Are central to mixed farming systems; consume agricultural waste products, help control insects and weeds, produce manure and waste for cooking, and provide draft power for transport
• Provide employment, in some cases especially for women
• Have a cultural significance, as the basis for religious ceremonies
As long as some people eat animal protein, there will be value associated with producing that protein efficiently, because efficiency is necessarily associated with sustainability, especially when it comes to agriculture.
The World Organization for Animal Health (OIE) estimates that an average of more than 20% of animal protein worldwide is lost as a result of disease; therefore, significant potential exists to reduce the environmental impact of animal protein production through improving the health of global livestock populations.
Disease prevention in food animals would seem to fit with almost all definitions of sustainability – improved animal health and welfare, decreased use of antibiotics, improved productivity, and decreased threat of zoonotic disease – a concept also known as One Health. One Health recognizes that the health of people is connected to the health of animals and the environment.
The widespread occurrence of animal disease in developing economies is one of the major factors negatively impacting livestock productivity. Generally, these diseases have the greatest impact on resource-poor livestock farmers and effective disease control is essential for poverty alleviation.
There are a number of technologies that can be employed to help prevent disease. The sterile insect technique (SIT) has been used to suppress and locally eradicate or prevent the invasion of New World and Old World screwworms in North America (US), Netherlands, Central America and Libya. The global elimination of Rinderpest (cattle plague) was achieved through a large-scale vaccination and surveillance program.
Figure 2: FIELD OF DEATH Cattle carcasses littered a pasture in South Africa in 1900 during a rinderpest epidemic. Credit G. R. Thomson
Selection for animals that are less susceptible to disease offers another approach to improve animal health. Breeders use a variety of breeding methods to select for animals that are less prone to disease. These include cross breeding and introgression of genes from resistant breeds, inclusion of disease traits in selection objectives and breeding programs, and the use of modern molecular techniques. Researchers are currently targeting important zoonotic diseases including Bovine Tuberculosis, Porcine Reproductive and Respiratory Syndrome (PRRS), African Swine Fever, Avian Influenza, Foot and Mouth Disease, and African animal trypanosomiasis.
Success in developing livestock that are more resilient and less susceptible to disease is an important component of the development of more productive and sustainable animal agricultural systems globally.
