Lester R. Brown
Chapter 9. Feeding Eight Billion Well: Producing Protein More Efficiently
Another way to raise both land and water productivity is to produce animal protein more efficiently. With some 37 percent (about 740 million tons) of the world grain harvest used to produce animal protein, even a modest gain in efficiency can save a large quantity of grain. 33
World meat consumption increased from 44 million tons in 1950 to 240 million tons in 2005, more than doubling consumption per person from 17 kilograms to 39 kilograms (86 pounds). Consumption of milk and eggs has also risen. In every society where incomes have risen, meat consumption has too, perhaps reflecting a taste that evolved over 4 million years of hunting and gathering. 34
As both the oceanic fish catch and the production of beef on rangelands have leveled off, the world has shifted to grain-based production of animal protein to expand output. And as the demand for meat climbs, consumers are shifting from beef and pork to poultry and fish, sources that convert grain into protein most efficiently. Health concerns among industrial-country consumers are reinforcing this shift.
The efficiency with which various animals convert grain into protein varies widely. With cattle in feedlots, it takes roughly 7 kilograms of grain to produce a 1-kilogram gain in live weight. For pork, the figure is over 3 kilograms of grain per kilogram of weight gain, for poultry it is just over 2, and for herbivorous species of farmed fish (such as carp, tilapia, and catfish), it is less than 2. As the market shifts production to the more grain-efficient products, it raises the productivity of both land and water. 35
Global beef production, most of which comes from rangelands, grew less than 1 percent a year from 1990 to 2006. Growth in the number of cattle feedlots was minimal. Pork production grew by 2.6 percent annually, and poultry by nearly 5 percent. The rapid growth in poultry production, going from 41 million tons in 1990 to 83 million tons in 2006 enabled poultry to eclipse beef in 1995, moving it into second place behind pork. World pork production, half of it now in China, overtook beef production in 1979 and has continued to widen the lead since then. 36
Fast-growing, highly grain-efficient fish farm output may also overtake beef production within the next decade or so. In fact, aquaculture has been the fastest-growing source of animal protein since 1990, largely because herbivorous fish convert feed into protein so efficiently. Aquacultural output expanded from 13 million tons in 1990 to 48 million tons in 2005, growing by more than 9 percent a year. 37
Public attention has focused on aquacultural operations that are environmentally inefficient or disruptive, such as the farming of salmon, a carnivorous species, and shrimp. These operations account for 4.7 million tons of output, less than 10 percent of the global farmed fish total, but they are growing fast. Salmon are inefficient in that they are fed other fish, usually as fishmeal, which comes either from fish processing wastes or from low-value fish caught specifically for this purpose. Shrimp farming often involves the destruction of coastal mangrove forests to create areas for the shrimp. 38
Worldwide, aquaculture is dominated by herbivorous species—mainly carp in China and India, but also catfish in the United States and tilapia in several countries—and shellfish. This is where the great growth potential for efficient animal protein production lies.
China , the world’s leading producer, accounts for an astounding two thirds of global fish farm output. Aquacultural production in China is dominated by finfish (mostly carp), which are produced inland in freshwater ponds, lakes, reservoirs, and rice paddies, and by shellfish (mostly oysters, clams, and mussels), which are produced mostly in coastal regions. 39
Over time, China has also developed a fish polyculture using four types of carp that feed at different levels of the food chain, in effect emulating natural aquatic ecosystems. Silver carp and bighead carp are filter feeders, eating phytoplankton and zooplankton respectively. The grass carp, as its name implies, feeds largely on vegetation, while the common carp is a bottom feeder, living on detritus. These four species thus form a small ecosystem, with each filling a particular niche. This multi-species system, which converts feed into high-quality protein with remarkable efficiency, allowed China to produce some 14 million tons of carp in 2005. 40
While poultry production has grown rapidly in China, as in other developing countries, it has been dwarfed by the phenomenal growth of aquaculture. Today aquacultural output in China—at 30 million tons—is double that of poultry, making it the first major country where fish farming has eclipsed poultry farming. 41
China ’s aquaculture is often integrated with agriculture, enabling farmers to use agricultural wastes, such as pig or duck manure, to fertilize ponds, thus stimulating the growth of plankton on which the fish feed. Fish polyculture, which commonly boosts pond productivity over that of monocultures by at least half, is widely practiced in both China and India. 42
With incomes now rising in densely populated Asia, other countries are following China’s aquacultural lead. Among them are Thailand and Viet Nam. Viet Nam, for example, devised a plan in 2001 of developing 700,000 hectares of land in the Mekong Delta for aquaculture, which now produces more than 1 million tons of fish and shrimp. 43
In the United States, catfish, which require less than 2 kilograms of feed per kilogram of live weight, is the leading aquacultural product. U.S. annual catfish production of 600 million pounds (about two pounds per person) is concentrated in the South. Mississippi, with easily 60 percent of U.S. output, is the catfish capital of the world. 44
When we think of soybeans in our daily diet, it is typically as tofu, veggie burgers, or other meat substitutes. But most of the world’s fast-growing soybean harvest is consumed indirectly in the beef, pork, poultry, milk, eggs, and farmed fish that we eat. Although not a visible part of our diets, the incorporation of soybean meal into feed rations has revolutionized the world feed industry, greatly increasing the efficiency with which grain is converted into animal protein. 45
In 2007, the world’s farmers produced 222 million tons of soybeans—1 ton for every 9 tons of grain produced. Of this, some 20 million tons were consumed directly as tofu or meat substitutes. The bulk of the remaining 202 million tons, after some was saved for seed, was crushed in order to extract 37 million tons of soybean oil, separating it from the highly valued, high-protein meal. 46
The 160 million or so tons of protein-rich soybean meal that remain after the oil is extracted is fed to cattle, pigs, chicken, and fish. Combining soybean meal with grain in roughly one part meal to four parts grain dramatically boosts the efficiency with which grain is converted into animal protein, sometimes nearly doubling it. 47
The world’s three largest meat producers— China, the United States, and Brazil—now all rely heavily on soybean meal as a protein supplement in feed rations. 48
The use of soybean meal in livestock feed, poultry, and fish both replaces some grain in feed and increases the efficiency with which the remaining grain is converted into livestock products. This helps explain why the share of the world grain harvest used for feed has not increased over the last 20 years even though production of meat, milk, eggs, and farmed fish has climbed. It also explains why world soybean production has increased nearly 14-fold since 1950. 49
Mounting pressures on land and water resources have led to the evolution of some promising new animal protein production systems that are based on roughage rather than grain, such as milk production in India. Since 1970, India’s milk production has increased more than fourfold, jumping from 21 million to 96 million tons. In 1997 India overtook the United States to become the world’s leading producer of milk and other dairy products. 50
The spark for this explosive growth came in 1965 when an enterprising young Indian, Dr. Verghese Kurien, organized the National Dairy Development Board, an umbrella organization of dairy cooperatives. The dairy coop’s principal purpose was to market the milk from tiny herds that typically averaged two to three cows each, providing the link between the growing market for dairy products and the millions of village families who had only a small marketable surplus. 51
Creating the market for milk spurred the fourfold growth in output. In a country where protein shortages stunt the growth of so many children, expanding the milk supply from less than half a cup per person a day 30 years ago to one cup today represents a major advance. 52
What is so remarkable is that India has built the world’s largest dairy industry almost entirely on roughage—wheat straw, rice straw, corn stalks, and grass gathered from the roadside. Even so, the value of the milk produced each year now exceeds that of the rice harvest. 53
A second new protein production model, one that also relies on ruminants and roughage, has evolved in four provinces in eastern China—Hebei, Shangdong, Henan, and Anhui—where double cropping of winter wheat and corn is common. Although wheat straw and cornstalks are often used as fuel for cooking, villagers are shifting to other sources of energy for this, which lets them feed the straw and cornstalks to cattle. Supplementing this roughage with small amounts of nitrogen in the form of urea allows the microflora in the complex four-stomach digestive system of cattle to convert roughage into animal protein more efficiently. 54
These four crop-producing provinces in China, dubbed the Beef Belt by officials, use crop residues to produce much more beef than the vast grazing provinces in the northwest do. The use of crop residues to produce milk in India and beef in China lets farmers reap a second harvest from the original grain crop, thus boosting both land and water productivity. 55
Although these new protein models have evolved in India and China, both densely populated countries, similar systems can be adopted in other countries as population pressures intensify, as demand for meat and milk increases, and as farmers seek new ways to convert plant products into animal protein.
The world desperately needs more new protein production techniques such as these. Meat consumption is growing twice as fast as population, egg consumption is growing nearly three times as fast, and growth in the demand for fish—both from the oceans and from fish farms—is also outpacing that of population. 56
While the world has had many years of experience in feeding an additional 70 million people each year, it has no experience with some 5 billion people striving to move up the food chain at the same time. For a sense of what this translates into, consider what has happened in China, where record economic growth has in effect telescoped history, showing how diets change when incomes rise rapidly. As recently as 1978, meat consumption in China consisted mostly of modest amounts of pork. Since then, consumption of meat—pork, beef, poultry, and mutton—has climbed severalfold, pushing China’s total meat consumption far above that of the United States. 57
While diversifying diets has dramatically improved nutrition in China, in most of the developing world nutritional disorders remain. For example, half the women in the developing world suffer from anemia, the world’s most common nutritional deficiency. Diets high in starchy food and low in iron-rich foods, such as leafy green vegetables, shellfish, nuts, and red meat, lead to insufficient iron in the diet, which in turn leads to low birthweights and high infant and maternal mortality. 58
Encouragingly, a decade of research by the Canadian-based Micronutrient Initiative has succeeded in fortifying salt with iodine and iron together. Just as iodine fortification of salt eliminated iodine deficiency diseases, so, too, can the addition of iron eliminate iron deficiency diseases. This double-fortified salt is being introduced initially in India, Kenya, and Nigeria. The prospect of eliminating iron deficiency disorders at an annual cost of 20¢ per person is one of the most exciting new options for improving the human condition in this new century. 59
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