“Together with pasturing, three quarters of all agricultural land is thus being used to generate animal products (e.g. milk, meat, and eggs), while only one quarter is used for producing non-meat and non-dairy products, such as cereals, vegetables, tuber crops, and other plants."
“The benefits associated with livestock are societal, economic, and environmental. They contribute 17% to the global food balance, in terms of calorific intake per person per day, and 33% of the protein in human diets (FAOSTAT, 2008).”
Mario Herrero and Philip K. Thornton, “Livestock
and global change: Emerging issues for sustainable food systems,” Proceedings of the National Academy of Sciences 110, no. 52 (2013): 20879, accessed July 25, 2014, doi:10.1073/pnas.1321844111
Hans Hurni, et al., “Key Implications of Land Conversions in Agriculture”, Wake Up Before It Is Too Late, Trade and Development Review 2013, UNCTAD, 221, http://unctad.org/en/PublicationsLibrary/ditcted2012d3_en.pdf