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Chapter 9. Feeding Seven Billion Well: Producing Protein More Efficiently
The second way to raise both land and water productivity is to produce animal protein more efficiently. With some 38 percent (about 730 million tons) of the world grain harvest used to produce animal protein, the potential for more-efficient grain use is large. 31
World meat consumption increased from 47 million tons in 1950 to 260 million tons in 2005, more than doubling consumption per person from 17 kilograms to 40 kilograms. 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. 32
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 animal protein climbs, the mix of protein products consumed is shifting toward those that convert grain into protein most efficiently, the lower-cost products. Health concerns have also prompted a shift from beef and pork to poultry and fish.
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 close to 4 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. 33
Global beef production, most of which comes from rangelands, grew less than 1 percent a year from 1990 to 2005. Growth in the number of cattle feedlots was minimal. Pork production grew by 2.5 percent annually, and poultry by nearly 5 percent. The rapid growth in poultry production, going from 41 million tons in 1990 to 80 million tons in 2005, enabled poultry to eclipse beef in 1995, moving it into second place behind pork. (See Figure 9–1.) World pork production, half of it in China, overtook beef production in 1979 and has continued to widen the lead since then. World beef production, constrained by both grazing limits and the inefficient feedlot conversion by cattle, is continuing to expand, but slowly. Indeed, within the next decade or so, fast-growing, highly grain-efficient aquacultural output may overtake beef production. 34
The big winner in the animal protein sweepstakes has been aquaculture, largely because herbivorous fish convert feed into protein so efficiently. Aquacultural output expanded from 13 million tons in 1990 to 42 million tons in 2003, growing by more than 10 percent a year. China, the leading producer, accounts for an astounding two thirds of global 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. 35
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. 36
As land and water for fish ponds become even scarcer, China’s fish farmers are feeding fish more grain concentrates, including soybean meal, to raise pond productivity. Using this technique, China’s farmers raised the annual pond yield per hectare from 2.4 tons of fish in 1990 to 4.1 tons in 1996. 37
In the United States, catfish, which require less than 2 kilograms of feed per kilogram of live weight, are the leading aquacultural product. U.S. annual catfish production of 600 million pounds (about two pounds per person) is concentrated in four states: Mississippi, Louisiana, Alabama, and Arkansas. Mississippi, with easily 60 percent of U.S. output, is the catfish capital of the world. 38
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 3.6 million tons of output, less than 9 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 plant 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. 39
World 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. 40
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. 41
In 2005, the world’s farmers produced 220 million tons of soybeans—1 ton for every 9 tons of grain produced. Of this, some 15 million tons were consumed directly as tofu or meat substitutes. The bulk of the remaining 205 million tons, after some was saved for seed, was crushed in order to extract 33 million tons of soybean oil, separating it from the highly valued, high-protein meal. By 2006, perhaps 2 million tons (7 percent) of these 33 million tons will be heading to service stations as biodiesel. 42
The 144 million tons of soybean meal that remain after the oil is extracted is fed to cattle, pigs, chicken, and fish, enriching their diets with high-quality protein. 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. 43
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. In the United States, which has long used soybean meal to upgrade livestock and poultry feed, the soybean meal share of feed rations climbed from 8 percent in 1964 to roughly 18 percent in recent years. 44
For Brazil, where the shift began in the late 1980s, soybean meal now makes up roughly 21 percent of the feed mix. In China, the realization that feed efficiency could be dramatically boosted with soymeal came several years later. Between 1991 and 2002, the soymeal component of feed there jumped from 2 percent to 20 percent. For fish, whose protein demands are particularly high, China incorporated some 5 million tons of soymeal into the 16 million tons of grain-based fish feed used in 2003. 45
With this phenomenal growth, soybean meal both replaced some grain in feed and increased the efficiency with which the remaining grain was converted into livestock products. This also 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. And it explains why world soybean production jumped from 16 million tons in 1950 to 220 million tons in 2005, a 13-fold increase. While the potential for raising feed efficiency with soybean meal has now been largely realized in key food-producing countries, there are still many developing countries that have not yet fully exploited its potential. 46
31. USDA, op. cit. note 1.
32. FAO , op. cit. note 3, with livestock data updated 14 July 2005; 2005 production estimates from FAO, Global Information and Early Warning System on Food and Agriculture (GIEWS), Food Outlook, No. 1 (Rome: April 2005).
33. Feed-to-poultry conversion ratio derived from data in Robert V. Bishop et al., The World Poultry Market—Government Intervention and Multilateral Policy Reform (Washington, DC: USDA, 1990); conversion ratio of grain to beef based on Allen Baker, Feed Situation and Outlook staff, ERS, USDA, discussion with author, 27 April 1992; pork data from Leland Southard, Livestock and Poultry Situation and Outlook staff, ERS, USDA, discussion with author, 27 April 1992; fish from Rosamond L. Naylor et al., “Effect of Aquaculture on World Fish Supplies,” Nature, vol. 405 (29 June 2000), pp. 1,017–24.
34. Figure 9–1 from FAO, op. cit. note 3, with livestock data updated14 July 2005; FAO, GIEWS, op. cit. note 32; fish data from FAO, FISHSTAT Plus, electronic database, at www.fao.org/fi/statist/FISOFT/ FISHPLUS.asp, updated March 2005.
35. FAO, op. cit. note 34.
36. Naylor et al., op. cit. note 33; polyculture in India from W. C. Nandeesha et al., “Breeding of Carp with Oviprim,” in Indian Branch, Asian Fisheries Society, India, Special Publication No. 4 (Mangalore, India: 1990), p. 1.
37. Krishen Rana, “Changing Scenarios in Aquaculture Development in China,” FAO Aquaculture Newsletter, August 1999, p. 18.
38. Catfish requirements from Naylor et al., op. cit. note 33; U.S. catfish production data from USDA, National Agricultural Statistics Service, Catfish Production (Washington, DC: February 2003), p. 5.
39. FAO, op. cit. note 34; Naylor et al., op. cit. note 33; Taija-Riitta Tuominen and Maren Esmark, Food For Thought: The Use of Marine Resources in Fish Feed (Oslo: WWF-Norway, 2003); Rebecca Goldburg and Rosamond Naylor, “Future Seascapes, Fishing, and Fish Farming,” Frontiers in Ecology and the Environment, vol. 3, no. 1 (February 2005), pp. 21–28.
40. FAO, op. cit. note 34; FAO, The State of World Fisheries and Aquaculture 2004 (Rome: 2004).
41. USDA, op. cit. note 1; Suzi Fraser Dominy, “Soy’s Growing Importance,” World Grain, 13 April 2004.
42. Use of soy is from author’s calculations based on USDA, op. cit. note 1, and on USDA, Foreign Agricultural Service (FAS), various agricultural reports (Washington, DC: various years); growth in biodiesel
discussed in more detail in Chapter 2.
43. USDA, op. cit. note 1.
45. Ibid.; David McKee, “Crushing Competition,” World Grain, 13 April 2004; USDA, FAS, China Oilseeds and Products Annual Report 2004 (Beijing: March 2004); Dominy, op. cit. note 41.
46. Historical statistics in Worldwatch Institute, Signposts 2002, CD-Rom (Washington, DC: 2002); USDA, op. cit. note 1.
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