An additional consideration is that maize, the principal feed grain, yields much more per hectare than wheat, the number one food grain. Recently, conversion rates of grains to meat, milk, and eggs have improved significantly in both developed and developing countries. Applying known technologies to a larger proportion of the world s animal populations offers the potential for substantial additional improvements in efficiency and, with continued investment in research, new technologies undoubtedly will contribute to additional increases. This suggests that grain requirement per unit of animal food product should decrease. However, the largest increases in demand are forecast for poultry, pork, and aquaculture products, which are foods from species requiring relatively high human-edible content diets.
Livestock have both positive and negative environmental effects.
Improved management of livestock grazing, better management and use of manure, and increased care in design and siting intensive production operations will be necessary to maximize beneficial effects and minimize detrimental effects of livestock. Government policies related to land use and economic development are important. Meeting projected demand for foods of both plant and animal origin in 2020, while sustaining the productive capacity of the land, will be challenging but feasible. Animal agriculture will continue to be an important part of food-producing systems. Investment in agricultural production research and development and implementation of policies that encourage production, while protecting the environment, will be essential to achieving the goal of an adequate global food supply.