Global animal food production is undergoing a major transformation that could lead to a higher risk of disease transmission from animals to humans, warns the Food and Agriculture Organisation of the UN – the FAO.
“The risk of disease transmission from animals to humans will increase
in the future due to human and livestock population growth, dynamic changes
in livestock production, the emergence of worldwide agro-food networks and a
significant increase in the mobility of people and goods,” the FAO says in a
policy brief published in Rome earlier this month.
“There is no doubt that the world has to depend upon some of the
technologies of intensive animal food production systems,” said FAO
livestock policy expert Joachim Otte. “But excessive concentration of animals in large scale industrial production units should be avoided and adequate investments should be made in heightened biosecurity and improved disease monitoring to safeguard public health,” he added.
As countries have become more affluent and the world’s population
continues to rise, demand for meat and other livestock products has grown
To satisfy this higher demand for meat products, livestock production
and densities have significantly increased, often close to urban centres.
Industrial animal production has become more concentrated, using fewer but
more productive livestock breeds.
The movement of animals and the concentration of thousands of confined
animals increase the likelihood of transfer of pathogens. Furthermore,
confined animal houses produce large amounts of waste, which may contain
substantial quantities of pathogens. Much of this waste is disposed of on
land without any treatment, posing an infection risk for wild mammals and
“These developments have potentially serious consequences for local
and global disease risks, which, so far, have not been widely recognized by
policy makers,” says FAO Chief Veterinary Officer Joseph Domenech.
Globally, pig and poultry production are the fastest growing and
industrializing livestock sub-sectors, with annual production growth rates
of 2.6 and 3.7 percent over the past decade.
As a consequence, in the industrialized countries, the vast majority
of chickens and turkeys are now produced in houses of 15 000 to 50 000
birds. The trend towards industrialization of livestock production can also
be observed in developing countries, where traditional systems are being
replaced by intensive units, most notably in Asia, South America and parts
Industrial pig and poultry production relies on a significant movement
of live animals. In 2005, for example, nearly 25 million pigs, more than two
million pigs per month, were traded internationally.
While the highly pathogenic H5N1 virus is currently of major global
concern, the ‘silent’ circulation of influenza A viruses (IAVs) in poultry
and swine should also be closely monitored internationally, FAO says. A
number of IAVs are now fairly widespread in commercial poultry and to a
lesser extent in pigs and could also lead to emergence of a human influenza