The United Nations' Food and Agriculture Organization recently recommended that livestock farms use natural resources more efficiently to meet the growing demand for meat and dairy products in more environmentally friendly way.

According to the FAO World Livestock 2011 report, global meat consumption is projected to rise 73% by 2050, while dairy demand is expected to grow by 58% from current levels, driven by growing population and incomes in developing countries. The world needs to boost output of cereal grains by 1 billion metric tons and produce 200 million extra metric tons of livestock products a year by 2050 in order to feed the population, which the United Nations projected to rise from about 7 billion currently to 9 billion by 2050.

"It is hard to envisage meeting projected demand by keeping twice as many poultry, 80 percent more small ruminants, 50 percent more cattle and 40 percent more pigs, using the same level of natural resources as currently," the report said.

The FAO report said production increases should come from improving efficiency of livestock systems in converting natural resources into food and from reducing waste. Large-scale, intensive animal-rearing farms, which will be key in increasing livestock output, should also reduce pollution generated from waste and greenhouse gases, cut the amount of water and grain needed to produce livestock protein ,and recycle agro-industrial byproducts, the report recommends.