https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6616661/
Following are selected writings about cell-based meat production as part of the effort to build a sustainable food supply for the world population.
~~ recommended by emil karpo ~~
Land and Water Usage in Beef Production Systems
Abstract Simple Summary
Consumers increasingly demand sustainable food production, including using world resources efficiently, avoiding environmental damage and ensuring good welfare of animals. Reports have suggested that beef production is costly in relation to world resource use and greenhouse gas production, so some consumers avoid beef. However, many reports refer mainly to feedlot systems. Ruminants can eat leaves that humans cannot eat, so if they are not fed grain, systems can be sustainable and valuable. This paper presents an analysis of the production of beef comparing all aspects of the use of land and conserved water for four production systems. It is suggested that conserved water use is a useful measure. Land use was the highest in extensive unmodified pasture systems, especially if the land became degraded. Less land was used in both feedlot and fertilised pasture systems and much less in semi-intensive silvopastoral systems. Conserved water use was the highest in feedlot systems, partly because of the grain fed to the cattle, lower in pasture systems and lowest in semi-intensive silvopastoral systems. This research indicates that, when beef production systems are being selected or consumers are deciding which beef to buy, extensive systems that degrade the land should be avoided, and well-managed extensive systems, especially semi-intensive silvopastoral systems, should be preferred to feedlot systems.
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U.S. could feed 800 million people with grain that livestock eat, Cornell ecologist advises animal scientists
MONTREAL -- From one ecologist's perspective, the American system of farming grain-fed livestock consumes resources far out of proportion to the yield, accelerates soil erosion, affects world food supply and will be changing in the future.
"If all the grain currently fed to livestock in the United States were consumed directly by people, the number of people who could be fed would be nearly 800 million," David Pimentel, professor of ecology in Cornell University's College of Agriculture and Life Sciences, reported at the July 24-26 meeting of the Canadian Society of Animal Science in Montreal. Or, if those grains were exported, it would boost the U.S. trade balance by $80 billion a year, Pimentel estimated.
With only grass-fed livestock, individual Americans would still get more than the recommended daily allowance (RDA) of meat and dairy protein, according to Pimentel's report, "Livestock Production: Energy Inputs and the Environment."
An environmental analyst and longtime critic of waste and inefficiency in agricultural practices, Pimentel depicted grain-fed livestock farming as a costly and nonsustainable way to produce animal protein. He distinguished grain-fed meat production from pasture-raised livestock, calling cattle-grazing a more reasonable use of marginal land.
Animal protein production requires more than eight times as much fossil-fuel energy than production of plant protein while yielding animal protein that is only 1.4 times more nutritious for humans than the comparable amount of plant protein, according to the Cornell ecologist's analysis.
Tracking food animal production from the feed trough to the dinner table, Pimentel found broiler chickens to be the most efficient use of fossil energy, and beef, the least. Chicken meat production consumes energy in a 4:1 ratio to protein output; beef cattle production requires an energy input to protein output ratio of 54:1. (Lamb meat production is nearly as inefficient at 50:1, according to the ecologist's analysis of U.S. Department of Agriculture statistics. Other ratios range from 13:1 for turkey meat and 14:1 for milk protein to 17:1 for pork and 26:1 for eggs.)
Animal agriculture is a leading consumer of water resources in the United States, Pimentel noted. Grain-fed beef production takes 100,000 liters of water for every kilogram of food. Raising broiler chickens takes 3,500 liters of water to make a kilogram of meat. In comparison, soybean production uses 2,000 liters for kilogram of food produced; rice, 1,912; wheat, 900; and potatoes, 500 liters. "Water shortages already are severe in the Western and Southern United States and the situation is quickly becoming worse because of a rapidly growing U.S. population that requires more water for all of its needs, especially agriculture," Pimentel observed.
Livestock are directly or indirectly responsible for much of the soil erosion in the United States, the ecologist determined. On lands where feed grain is produced, soil loss averages 13 tons per hectare per year. Pasture lands are eroding at a slower pace, at an average of 6 tons per hectare per year. But erosion may exceed 100 tons on severely overgrazed pastures, and 54 percent of U.S. pasture land is being overgrazed.
"More than half the U.S. grain and nearly 40 percent of world grain is being fed to livestock rather than being consumed directly by humans," Pimentel said. "Although grain production is increasing in total, the per capita supply has been decreasing for more than a decade. Clearly, there is reason for concern in the future."
EIGHT MEATY FACTS ABOUT ANIMAL FOOD
From "Livestock Production: Energy Inputs and the Environment"
By David Pimentel
-- WHERE'S THE GRAIN? The 7 billion livestock animals in the United States consume five times as much grain as is consumed directly by the entire American population.
-- HERBIVORES ON THE HOOF. Each year an estimated 41 million tons of plant protein is fed to U.S. livestock to produce an estimated 7 million tons of animal protein for human consumption. About 26 million tons of the livestock feed comes from grains and 15 million tons from forage crops. For every kilogram of high-quality animal protein produced, livestock are fed nearly 6 kg of plant protein.
-- FOSSIL FUEL TO FOOD FUEL. On average, animal protein production in the U.S. requires 28 kilocalories (kcal) for every kcal of protein produced for human consumption. Beef and lamb are the most costly, in terms of fossil fuel energy input to protein output at 54:1 and 50:1, respectively. Turkey and chicken meat production are the most efficient (13:1 and 4:1, respectively). Grain production, on average, requires 3.3 kcal of fossil fuel for every kcal of protein produced. The U.S. now imports about 54 percent of its oil; by the year 2015, that import figure is expected to rise to 100 percent.
-- THIRSTY PRODUCTION SYSTEMS. U.S. agriculture accounts for 87 percent of all the fresh water consumed each year. Livestock directly use only 1.3 percent of that water. But when the water required for forage and grain production is included, livestock's water usage rises dramatically. Every kilogram of beef produced takes 100,000 liters of water. Some 900 liters of water go into producing a kilogram of wheat. Potatoes are even less "thirsty," at 500 liters per kilogram.
-- HOME ON THE RANGE. More than 302 million hectares of land are devoted to producing feed for the U.S. livestock population -- about 272 million hectares in pasture and about 30 million hectares for cultivated feed grains.
-- DISAPPEARING SOIL. About 90 percent of U.S. cropland is losing soil -- to wind and water erosion -- at 13 times above the sustainable rate. Soil loss is most severe in some of the richest farming areas; Iowa loses topsoil at 30 times the rate of soil formation. Iowa has lost one-half its topsoil in only 150 years of farming -- soil that took thousands of years to form.
-- PLENTY OF PROTEIN: Nearly 7 million tons (metric) of animal protein is produced annually in the U.S. -- enough to supply every American man, woman and child with 75 grams of animal protein a day. With the addition of 34 grams of available plant protein, a total of 109 grams of protein is available per capita. The RDA (recommended daily allowance) per adult per day is 56 grams of protein for a mixed diet.
-- OUT TO PASTURE. If all the U.S. grain now fed to livestock were exported and if cattlemen switched to grass-fed production systems, less beef would be available and animal protein in the average American diet would drop from 75 grams to 29 grams per day. That, plus current levels of plant-protein consumption, would still yield more than the RDA for protein.
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Achieving Peak Pasture - excerpt from executive summary
Pastureland is by far the single largest human land use on the planet. Globally, we use twice as much land for producing meat and milk from cattle and other ruminants as we do for growing crops. For centuries, global pasture area expanded, with severe environmental consequences. Since the 1700s, an area nearly the size of North America has been converted to pasture. Further, pasture expansion has been a major driver of deforestation in the Amazon and degradation of many of the world’s natural grasslands, threatening biodiversity and worsening climate change. In the past 20 years, however, something remarkable has occurred, something that few predicted: global pasture has begun to decline. According to data from the Food and Agriculture Organization of the United Nations, there are 140 million fewer hectares of pasture today than there were in 2000, an area roughly the size of Peru. Many high-income countries saw pasture area peak as early as the 1960s and decline consistently since then. But in the past two decades, this pattern has spread to most of the rest of the world, with more than two-thirds of all countries now experiencing flat or declining pasture area. Notably, since 2000, pasture has also leveled off in the rapidly developing middle-income countries that saw the greatest pasture expansion in the late 20th century, including China and Brazil, as well as in low-income countries. Driving this global trend is increasing productivity — producing more ruminant meat and milk with less land. Between 2000 and 2013, even as pasture area has declined, ruminant meat and milk production has gone up by 13% and 32%, respectively. In other words, there has been a great decoupling of production from pastureland — a “livestock revolution.” 4 While some of this productivity growth is the result of raising more animals on the same amount of pasture (that is, higher stocking density), each animal is also producing more milk and meat. Both stocking densities and animal yields have improved across most of the world, except in sub-Saharan Africa (SSA), where animal yields have improved little, if at all, and stocking densities are reaching unsustainable levels. Pasture’s decline could be a boon for the environment, especially if it continues, but the future is by no means certain. One factor in particular threatens to reverse pasture’s contraction. Rapid population and economic growth in parts of the developing world, especially SSA, in combination with persistently low animal yields, could herald a major expansion of pasture. Although economic development will probably drive productivity improvements along with demand, it is likely that SSA will experience a period of substantial pasture expansion as long as yields fail to keep pace with demand, following the pattern of other developing regions.
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Cell-based meat is moving from the lab to dinner plates - The Boston Globe
It may never have occurred to you to hanker for a supper of, say, flame-broiled North Atlantic right whale, braised shank of black rhino, or of another critically endangered species. But should such a craving come, it may soon be possible to satisfy it, according to scientists and the technological promises of a fast-emerging industry.
It may also be possible to dine on a filet mignon that won’t raise cholesterol levels, consume bacon that rabbis might consider kosher, and grill burgers a vegetarian might approve of — all without killing animals or contributing to the massive greenhouse gas emissions associated with raising animals for food.
Recent advances in so-called cultivated meat — harvested from cell cultures in specially engineered steel vats, rather than from slaughtered animals — and a recent landmark decision by the US Department of Agriculture allowing two California companies to sell their cell-based chicken thighs in restaurants, are propelling what proponents say is a meat revolution with almost unlimited possibilities.
“This is a game-changer,” said David Kaplan, a professor of biomedical engineering who oversees the Tufts University Center for Cellular Agriculture, which has received millions of dollars in federal grants to help a growing number of universities and startups move cell-based meat from the lab to dinner tables. “As consumers start to understand that cell-based meat is healthier, safer, higher-quality food, I think it’s inevitable that this is how our food will eventually be produced.”
There are critics who say such predictions are premature, but mounting worries about feeding the world and the environmental impact of raising meat have helped fuel a surge in research and private efforts to make lab-grown varieties real. More than 150 companies and research institutions around the world, including several in Massachusetts, are working on using cells to grow food in labs. They’ve raised investment capital of nearly $3 billion collectively, according to the Good Food Institute, a Washington-based nonprofit that promotes cell- and plant-based meat.
Elliot Swartz, a scientist at Good Food Institute, expects the USDA’s approvals in June — which followed the Food and Drug Administration’s findings last year that the companies’ chicken is safe to eat — will lead to even more investment. He also expects other countries will now be more likely to approve cell-based meat. In 2020, Singapore became the first country to allow it to be sold.
“Many global regulatory agencies look to the United States Food and Drug Administration for their leadership in the safety assessment of new food,” he said. “With this approval, we anticipate that many global regulators will accelerate the development of clear regulatory pathways.”
At the same time, advances in the ability to isolate and grow stem cells, the creation of optimal nutrients to feed them, and methods for engineering tissue have produced results that increasingly resemble, in taste and nutritional value, meat from slaughtered animals.
Researchers say they can now grow meat that has the shape, texture, and taste of a chicken breast, fish filet, or fat-marbled steak. Creating elements like skin and bones is also possible, and animal parts like drumsticks or rib roasts are also within reach, they say, though the process of creating them is still complicated and expensive. They also have the ability to mimic flavor variations of grass- or corn-fed beef, simply by feeding cells a special nutrient brew of whatever an animal might eat.
In theory, the meat of any living animal could be grown — and even some that aren’t. This year, an Australian company made a woolly mammoth meatball using the long-extinct creature’s DNA.
“This technology will completely change our palates,” Kaplan said. “We now eat a narrow range of species. With this technology, you can take any animal on the planet and create food.”
As for how well these new products go over with ordinary consumers, there hasn’t yet been much opportunity. But at a recent tasting tour in California, James Dolgin, a 27-year-old graduate student in Kaplan’s lab, sampled a smoked chicken salad that was good enough for him to want more, he said.
“If I had a blind taste test, I wouldn’t have known the difference,” Dolgin said. “They mimicked the taste and the smell and texture pretty well.”
“No product was perfect,” he added. But “I would have loved second helpings.”
The first lab-grown burger, the product of tens of billions of cells cultivated in a Dutch lab, was served 10 years ago at a conference in London — at a cost of $330,000 for the first batch. Six years later, the makers of that burger said their costs had fallen to less than $10 to produce the same beef patty.
1. Acquire cells from a donor animal
The first step in the process is to isolate and store cells from a food animal.
2. Expand cells with culture media in bioreactors
Cells are fed an oxygen-and nutrient-rich culture serum while they proliferate within a sterile vessel called a bioreactor or cultivator.
3. Cells mature into meat during differentiation
Cells are triggered to mature into muscle and fat tissues by changes in media or other external cues. Sometimes this process is coupled with a scaffold material to provide texture and structure to the product.
4. Meat is harvested and packaged
The meat tissues are removed from the bioreactor, washed, shaped into anything from patties to nuggets, and flavored with salt, spices, or other ingredients.
Skeptics of cell-based meat say the advances and falling costs aren’t enough — and might never be sufficient — to enable its production at a scale to feed the world and halt the slaughter of billions of animals every year.
They argue that biological limitations, such as cells failing to thrive because of ammonia and other cell waste that build up in bioreactors, could make it hard to scale up at sufficient levels. They also say that costs must fall more than 1,000-fold for cell-based meat to be competitive with regular meat. And they point to a range of unknowns, such as whether there could be unforeseen dangers from cell-based meat.
They also question whether there’s really a market for such meat, and whether consumers will view it as unnatural or similar to genetically modified foods, which have been tarred as Frankenfood.
They point to the relative failures of plant-based meats, such as Beyond Burgers and Tofurkey, to reach a broader market. Last year, plant-based meat products had gained just 1.3 percent of the meat market, and in the second financial quarter of this year, Beyond Meat reported a 30 percent decline in revenue. Over the past two years, the company’s stock has fallen 90 percent.
“Overall, while the technology works, the business models don’t,” said Paul Wood, a biotechnology professor at Monash University in Australia, and the lead author of a recent paper in the journal Animal Frontiers that raised questions about the future of cell-based meat. “Investment companies talk about this as an impact investment, but if the products never get beyond high-end restaurants, they will have no impact on food sustainability.”
Executives and others in the industry insist that the current challenges will be overcome, and that the planet has little choice but to do just that. With ever-rising demands for protein from a growing, more urbanized global population, as well as the increasing urgency to reduce carbon emissions, the existing food systems are unsustainable, they note.
Today, global food systems are responsible for more than a third of the planet’s climate emissions, according to the United Nations Without changes, those emissions could grow as the global population is expected to near 10 billion people by 2050.
“I am optimistic that these problems will be solved, given progress to date, but they are not easy problems,” said Yossi Quint, chief executive of the Cambridge-based Ark Biotech.
His two-year-old company has raised more than $13 million to help solve the problem of producing large amounts of cell-based meat at reasonable costs by building industrial bioreactors and operating systems. Bioreactors are temperature- and oxygen-controlled steel chambers where the cells are grown.
At the company’s labs near Kendall Square, where stainless steel prototypes rise toward the high ceilings of their loft-like space, Quint said their bioreactors will be 90 percent cheaper than existing ones, 50 times bigger, and will “dramatically improve yields.”
He called the federal government’s approval of cell-based meat sales “a watershed moment” for the industry.
“Over the next decade,” Quint said, “I expect cultivated meat to move from a luxury available only in a handful of restaurants to a product on supermarket shelves, at a price point affordable to most consumers.”
Others in the Boston area developing cell-based products include Tender Food, which has so far mainly focused on plant-based “meat-free meat,” and TurtleTree, which is using microbial cells to develop “precision fermentation technology” to make a milk protein known as lactoferrin that it says “nutritionally enhances not only plant-based foods but every single food product.”
Aletta Schnitzler, TurtleTree’s chief scientific officer, said the company plans to start commercial production of their milk proteins later this year. Their first products, she said, will help cell-based meat companies take a hybrid approach by encouraging them to combine their meat with plant-based ingredients, reducing the costs.
“We expect to see technologies used in combination to bring a range of accessibly priced, hybrid products to market, while giving producers time to scale up,” said Schnitzler, who oversees a research and development team in Beverly.
At Good Meat, one of the California companies that received USDA approval to sell its lab-grown chicken in restaurants, officials acknowledged the industry’s challenges.
“This is barely the first inning,” said Andrew Noyes, a spokesman for Good Meat, which aims to change “the way the world eats . . . without tearing down a forest or taking a life.”
The company is working with the acclaimed chef José Andrés, who has been dressing up its cultivated meat products as “anticuchos de pollo,” which are slathered in a Peruvian sauce made with yellow chile peppers, parsley, cilantro, garlic, olive oil, and salt and vinegar. Andrés, a member of Good Meat’s board, has also been holding a weekly tasting menu at China Chilcano, his restaurant in Washington, D.C.
Noyes declined to comment on how much it costs the company to make its cultivated chicken, but he said “our production costs are quite still high” and added that “we are not making a profit on anything we sell to restaurants.”
The company aims to produce tens of millions of pounds of meat before the end of the decade, Noyes said, and expects to do so with more than $250 million it has raised to build large-scale production plants. So far, they’ve sold less than 5,000 pounds of their chicken, he said.
By comparison, in 2020, nearly 60 billion pounds of broilers — chickens bred for food — were sold in the United States, according to the USDA.
At Tufts’ Center for Cellular Agriculture, which received a $10 million grant from the USDA to find ways to advance the field, Kaplan’s team of scientists has been working for the past seven years on finding ways to address many of the industry’s challenges. They have already spun off some of their research to start a company called Wanda Fish, which is developing cultivated fish fillets that they say have “the nutrition, taste, texture, and mouth feel of real fish.”
Kaplan, too, acknowledged the challenges facing the industry, but he scoffed at the naysayers.
“It’s not a question of whether we can do this; it’s a question of when and at what scale,” he said. “In the long run, this is how food will be made in the future.”
David Abel can be reached at david.abel@globe.com. Follow him @davabel.
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