Although the consumption of meat and milk in the industrialized world is significantly greater on a per capita basis than in the developing world, the growing numbers of middle class consumers in the developing world is the force that propels overall demand and prices upward. Table 8-1 outlines the projected changes in meat and milk consumption in developing and industrialized countries between 1980 and 2030. The estimates are for a 560% increase in consumption of meat, mainly pork and poultry, and a 430% increase in milk consumption in the developing world, far beyond the growth of populations. Accompanying this is the increased demand for feed grains, especially corn and soybean, on the world markets. These figures emphasize that global food supplies are directly tied to the health and efficiency of the livestock and poultry industries and point to the growing importance and opportunities for the veterinary profession in sustaining food security in the future.
FAO estimates that available arable land will shrink by approximately 33% from 0.23 hectares (approximately 0.5 acre) per person in 2000, to 0.15 hectares (approximately 0.33 acre per person) by 2050 (www.fao.org/hunger/en/). It is not clear that these figures are adjusted for the loss of arable land from urban sprawl, but they nevertheless indicate that global agriculture must greatly increase its efficiency, without damaging the environment, a difficult task as the available land per person decreases.
The importance of production efficiency in relation to environmental sustainability can be illustrated by a comparison of the effects of milk yields per cow. Recognizing the importance of animal protein to childhood physical and cognitive development, several countries in Southeast Asia have promoted expansion of their nation’s dairy industry with the goal of providing a glass of milk each day to every child in the nation. The challenge for the dairy industry and the veterinary profession in these countries is to understand how the goal can be fulfilled. Milk yields per cow in China and Thailand, for example, average 27% of yields in the United States (2,423 kg/yr vs. 8,861 kg/yr) (China Livestock Yearbook, 2007; FAO, 2006; FAO, 2009). China is attempting to meet the increasing demand by increasing the number of cows in the nation’s dairy herd. But increasing the number of low-producing animals increases the cost per gallon of milk in terms of animal maintenance requirements, numbers of replacement animals, food and water consumption, land use, methane release, and waste production, raising questions about the long-term sustainability of the approach. Progress in the U.S. dairy industry over the past 60 years illustrates the advantages of increased production efficiency. In 1950, there were 22 million milk cows in the United States with an average annual yield of 5,314 lbs (664 gallons) per cow. Using the figure of 1.4 cow units per acre (cow + replacement heifer), this computes to approximately 3,796 lbs of milk (474 gal-