Competition between Livestock and Mankind for Nutrients: Let Ruminants Eat Grass

As we contemplate the challenge of feeding more than 8 billion people —more than three quarters living in developing countries —the even greater challenge will be feeding their grandchildren. Consideration of competition between livestock and mankind for nutrients must include both near-term food needs and long-term sustainability of agricultural production systems. Producing more livestock products at the expense of eroding the natural resource base is not an acceptable solution. Livestock have been denigrated as both competitors for food and degraders of the natural resource base for food production. These often emotionally argued allegations against livestock generally do not stand up to objective analysis. Livestock arc most often complementary elements of food production systems, converting otherwise unused feed sources to highly desired food and livestock products such as leather and wool. Moreover, well-managed livestock are positive contributors to the natural resources base supporting balanced agricultural systems. In this chapter, the following points are addressed from the perspective of current and future role for livestock in feeding 8 billion people: . . . • Growing demands for human food and livestock feed • Domesticated food-producing animals • World livestock production systems • Human food preferences and requirements • Dietary requirements and conversion efficiencies • Contributions of science to livestock improvement . . . The overarching issue is the difference in the current and future role for livestock in developed and in developing regions. Less than 11 percent of the global land mass of 13.3 billion hectares is cultivated; the remainder supports permanent pasture, 26%; forest, 31%; and other nonagricultural uses, 32% (U.N. data as cited by Waggoner, 1994). The concerns about competition between livestock and mankind for nutrients center primarily on grains and legumes grown on arable land. Even the most avid vegetarians have little taste for the forages and other herbaceous materials from pasturelands, forests, roadsides, and fence rows that arc consumed by livestock. Since the 18th century, the amount of land cultivated has increased from approximately 0.3 to 1.5 billion ha (Richards, 1990, as cited by Waggoner, 1994). This increase in cultivated land has primarily come at the expense of forest and grasslands.