"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.
Demand for meat and other livestock products has grown in step with population growth and rising purchasing power, according to the Rome-based agency.
At the same time, "dynamic changes in livestock production, the emergence of worldwide agro-food networks and a significant increase in the mobility of people and goods" are combining to increase the risk of disease transmission from animals to humans, it said.
"The movement of animals and the concentration of thousands of confined animals increase the likelihood of transfer of pathogens," states FAO's policy brief, "Industrial Livestock Production and Global Health Risks," noting that slaughterhouses are often close to urban centres.
In addition, the large amounts of waste from confined animal houses "may contain substantial quantities of pathogens (and is) largely disposed of on land without any treatment, posing an infection risk for wild mammals and birds," the brief says.
While the risk of bird flu is well known, the FAO also urges close international monitoring of the "silent" circulation of influenza A viruses in poultry and swine.
"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 pandemic," FAO said.