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Food

BIO 4730/5730 Environmental Biology Topic 6

NourishmentThere are two kinds of food insufficiency. Both areworldwide problems:

Undernourishment: lack of sufficient energy in available food Lack of sufficient energy to work or move Often leads to famines and dramatic population decreases

Malnourishment: lack of specific nutrients in food, e.g.,proteins (amino acids), vitamins, mineral nutrients Long-term and insidious: people may not die outright, but are less

productive May suffer from mental and physical disabilities, e.g., marasmus

(progressive emaciation from lack of protein and calories);kwashiorkor (failure of normal neurological development due tolack of sufficient protein); chronic hunger (enough food to survive,but no excess for activity or normal reproduction)

Sources of Food: PlantsMore than 250,000 species of plants

Only about 3000 tried as crops Only about 300 grown for food Only about 100 grown on a large scale

Most of world food supply is provided by only 20species: Wheat, rice, corn - major source Together with remaining small grains: barley, oats, sorghum,

millet, and rye, this is the bulk of the food supply Remaining foods are more regional: potatoes, sweet potatoes,

cassavas, soybeans, sugar cane, sugar beets, peanuts, field beans,chickpeas (‘garbanzo beans’), pigeon peas, bananas, and coconuts

Also important are forage crops for livestock Alfalfa, sorghum, grasses (hay) 14 million ha in U.S. planted in alfalfa (50% of world’s total)

Only 11% of Earth’s land surface is considered arable (suitable for plantcrops)

About 25% of the land(190 million ha) in theU.S. is arable 80% of this (including

all of the best land)was in production bythe mid-1970s

Additional 300million ha was inpasture and rangeland

Amount of both isdecreasing About 1 million ha/yr

due to urbanization,highways, soil erosion

Additional land added by irrigating dry areas, draining wetlands Net loss is about 1.5 million ha/year

Arable Lands

6

7

8

9

10

11

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

2000 2020 2040 2060 2080 2100

Per capita Land Area (ha/pers)Arab

le L

and

Area

( bi

llion

ha)

Num

ber o

f Hum

ans

(bill

ions

)

“Buy land, they ain’t making any more of the stuff.”–Will Rogers

Approaches to Agriculture Resource-based agriculture

Production limited by availability of resources andeconomic demand usually exceeds production

Introduced about 10,000 Y BP Low (or no) use of mechanized technology Resource conservation (land, water, energy) important Often dependent on biologically-based technologies

The world as a whole is moving from a resource-based toa demand-based agriculture Production determined by economic demand, and is limited

by that demand Accompanied Industrial Revolution Based on highly mechanized technology High demand for resources (land, water, energy) Little use of biologically-based technologies

Other Uses for CroplandsNot all croplands produce food. Extensive acreages are diverted to produceother human commodities (cash crops) that have little or no caloric value,including:

Fibers (e.g., cotton, rattan, hemp) Drugs (e.g., poppies, coco) Beverages (e.g., coffee, teas, beers,

wines) Timber and pulpwood plantations Fuel (e.g., plant oils, methanol) Herbs and spices Remove land from other

production, but may providelocal residents with important income

May have positive or negative environmental impacts Production of some of these (e.g., many spices) can be done in natural

ecosystems However, modern methods of increasing yields (e.g., machine tillage, pesticide

application) are increasingly employed in the production of some of theseproducts

AgroecosystemsModern farming creates abnormal ecosystems that differfrom natural ecosystems in several important ways:

Ecological succession is haltedStopping succession takes time, energy, labor, money

Biological diversity decreasesClearing land and resulting plowing disturbs soil like nothing else:

causes loss of soil flora (that produce nutrients for crop plants) andsoil fauna (that convert detritus into organic soil)

Large areas often planted with a single species or even a single strain(‘monocultures’). Increases nutrient depletion and potential severityof disease outbreaks.

Communities are simplified and ‘food webs’ are more linear Crop plants are regularly spaced in rows

Increases erosionProvides easy access to pests

Agroecosystems have much lower primary productivitythan the natural ecosystems they replace!!!

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Food

BIO 4730/5730 Environmental Biology Topic 6

Habitat destruction: especially deforestation, plowing, and overgrazingPlowing (tillage) is one of the mostdestructive of all human activities:Disturbs soil like nothing else!!!Results in loss of the very soil flora

and fauna that form new soil!!!Soil depletion: removal of

essential nutrient elements Results in increased need for…Fertilization: addition of

limiting nutrients Nitrogen generally most limited nutrient in terrestrial ecosystems Over-fertilization produces similar effects to soil erosion on aquatic

ecosystems, also kills soil organismsPesticides and herbicides: removing the competition Very destructive to non-target species Residues in food can be mutagenic or carcinogenic Biomagnification of pesticides/herbicide residues or breakdown

productsIntroduction of exotic pathogens and pests

Environmental Impacts of Agriculture Soil Erosion: Removal of soil particles by wind and water

(topsoil loss exceeds topsoil formation) Deforestation, poor agricultural practices, and

overgrazing are all contributing factors Worst effects occur on slopes used for

agriculture, where soilconservation practices are not implemented Further damages or eliminates normal soil flora and

fauna May change successional state (or even the biome

type) Runoff damaging to aquatic ecosystems, due

to increased turbidity, infilling with silt,and/or nutrient eutrophication

Causes loss of productivity in both naturaland agricultural ecosystems

Increases particulate air pollution Human practices have caused massive soil

erosion over historical time

Runoff from soil erosion: BetsibokaRiver into Indian Ocean (Madagascar)

Gulf Sediment Agricultural runoff and otherpollutants flow into the Mississippi River andinto the Gulf of Mexico where they nourishphytoplankton, creating, in effect, a dead zone forfish.

Irrigation and Soil Salinization Irrigation in arid and semiarid regions often results in high soil

concentrations of mineral salts Irrigation water contains small amounts of dissolved salts When the water evaporates, salts are left behind Many years of irrigation causes gradual accumulation of salt in soil, eventually

reaching toxic levels

How soil salinization affects plants Water diffuses from areas of high to low concentration (concentration

of water depends on amount of dissolved solutes) When soil water contains

greater amounts ofdissolved solutes thanplant tissues, water movesout of the plant’s root haircells by osmosis

The root hair cells shriveland die. Without them, theplant can no longer absorbwater and minerals, and theplant dies

Types of Animal Foods

Whole animals: small arthropods, some molluscs, small vertebrates Muscle tissue: mammals, fishes, mollusks, large arthropods Internal organs (e.g., liver, kidneys): primarily mammals, some other

vertebrates Milk and milk products (whey, cheeses, yoghurt): mammals only,

primarily ruminants (cattle, sheep, goats, and reindeer), and horses Blood: primarily cattle, some fishes Gonads

• Mammal testes (cattle, pigs)• Gonads of fishes and sea urchins

Sex cells• Eggs of poultry, fishes, and sea urchins• Sperm (milt) from fishes

But Man is a carnivorous production,And must have meals, at least one meal a day;He cannot live, like woodcocks, upon suction,But, like the shark and tiger, must have prey;Although his anatomical constructionBears vegetables, in a grumbling way,Your laboring people think beyond all question,Beef, veal, and mutton, better for digestion.

George Gordon (Lord Byron), Don Juan

Influences on Choice of Animal FoodsCultural influences• Religious dietary prohibitions (e.g.,

cattle by Hindus, pork by Muslimsand Jews, shellfish by Jews)

Prejudice• ‘Classism’: eating some foods seen as a sign of poverty or “lack of breeding”• Avoid eating animals that are recognized as “special”, e.g., pet species• Avoid eating unfamiliar animals or animal parts• Avoid eating “recognizable” animals or animal partsEthical issues• Avoid eating animals or animal parts because “eating animals is wrong”,

“eating animals harms the environment”, etc.Genetic reasons• Lactose intolerance in many African and Asian populationsHealth issues• Avoid eating animals or animal parts because of concerns about cholesterol,

saturated fat, prion diseases (“mad cow”, chronic wasting disease), etc.

If you dine with pretentious people, here are someitems that are sure to impress: diced yak, badgergumbo, jackal tartare, loin of chipmunk, curriedwoodpecker, penguin scallopini, sweet-and-sourloon heads, wombat souvlaki…

George Carlin, Brain Droppings

Which Animals Do You Eat?Kile nyama nyama tu. (“Every meat is meat.”)

-Swahili sayingMammals (cows, pigs, sheep, goats, horses, camels, deer,carnivores, opossums, seals, elephants, whales, rabbits,rodents, primates)?Birds (chickens, turkeys, ducks, geese, ostriches, emus,grouse, pheasants, quail, doves/pigeons, starlings)?Reptiles (turtles, crocodilians, snakes, lizards)?Amphibians (frogs, salamanders)?Bony fishes (tuna, billfishes, salmon/trout, catfish, carp,tilapia, flatfishes, perch, ‘orange roughy’, ‘Chilean seabass’, redfish, bass, mahi-mahi, snapper, grouper,monkfish, eels)?Cartilaginous fishes (sharks, skates, ratfishes)?Jawless fishes (lampreys, hagfishes)?Echinoderms (sea cucumbers, sea urchins and their roe)?Arthropods (shrimp, lobsters, crabs, crayfish, insects,centipedes, spiders, scorpions)?Molluscs (bivalves, cephalopods, snails)?Annelids (earthworms)?Cnidarians (sea anemones, jellyfish)?

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Food

BIO 4730/5730 Environmental Biology Topic 6

What Animal ‘Parts’ Will You Eat?Skeletal muscles?Skins?Feet?Tails?Tongues?Hearts?Lungs?Pancreas?Livers?Stomachs (“tripe”)?Intestines (“chitterlings”)? Mesenteries?Lymph nodes (thymus glands, AKA“sweetbreads”)? Spleens?Gonads, eggs, sperm?Kidneys?Milk?Blood?Bones?Brains?Eyes?

People who love sausage and respect the law shouldnever watch either one being made.

Otto von BismarckThe point here is, many of these “pieces-parts” are perfectlyedible, but are “waste products”, as far as you’ve beenacculturated.

Sources of Food: HuntingMany animal species have been extirpated by humans:

Giant tortoises, mammoths, mastodons, and Irishelk hunted to extinction by early humans 1000’s ofyears ago

Moas and other giant ratite birds hunted toextinction by Maori (by 16th century) andAborigines (date unknown)

Despite conservation attempts, the dodo washunted to extinction by Europeans in the 16thcentury

Passenger pigeons and heath hens were hunted toextinction by Americans in 19th Century

Coastal populations of all species of whales andseals have been essentially wiped out

What is “Domestication”?Domestication is a population-level process, in which natural section pressuresupon members of a wild population are removed or modified, and artificialselection is introduced (taming happens to individuals)

According to Brisbin (1977), members of a wild population may naturally enter a“pariah complex”, gravitating toward humans who may partially, but notcompletely, influence reproduction (1)

Members of the “pariah complex” that becomeassociated with humans (2) may be recruitedinto domestic population(s)

‘Escapees’ from domestication mayreturn to the pariah complex (3), orform a “feral population” (4), thatonce had human influence over itsbreeding, but no longer does

Feral organisms may interbreed with membersof the pariah population (5, 6), or may ‘return tothe fold’, i.e., reenter the domestic populationvia the pariah complex (2). The wild populationmay eventually be replaced by the pariah and/orferal members

In extreme cases, e.g., the California condor, a wild population may bypass thepariah status and enter the domesticated state directly (7)

Africa Near East

East Asia Europe N. America Pacific I. S. America

sorghum

tef

pearl millet

finger millet

cow pea

African rice

yam

oil palm

watermelon

okra

wheat

barley

pea

chickpea

fava bean

lentil

carrot

safflower

olive

fig

date

rice

millet

buckwheat

soybean

adzuki bean

turnip

Chinese radish

canola seed

apricot

peach

water chestnut

cucumber

sesame

oat

rye

beet

hazelnut

plum

apple

cabbage

almond

pear

lettuce

carob

onion

grape

corn (maize)

common bean

lima bean

chili pepper

sweet potato

tobacco

sunflower

papaya

pumpkin

tomato

bottle gourd

squash

breadfruit

sweet potato

taro

arrowroot

coconut

lemon

grapefruit

orange

mango

banana

eggplant

sugar cane

quinoa

common bean

manioc

squash

cacao

sweet potato

potato

avocado

cashew

pineapple

papaya

peanut

Domestication of Plants(List includes crops grown for food, not spices, herbs, etc.)

Desirable Characteristics for DomesticationValue to humans Useful as a source of food or fiber, in work,

or in hunting

Diet Large herbivores offer substantial energy use (and safety) advantages over carnivores

Growth Rapidly attain their desired size

Breeding Must breed in captivity

Disposition Amenable to human lifestyles and tractable, little tendency to panic when startledSociability Herding social structure and hierarchy that favors domestication

Africa is a ‘Pleistocene environment’, with many largeherbivores that have never been domesticated, including

ruminants such as cattle (e.g., the cape buffalo andwildebeest), antelopes/gazelles, and camels (giraffe and

okapi). In this predator-rich environment, herbivorestend to be large, fast, wary, aggressive, and non-social,

and thus not very good candidates for domestication!

Domestication of Animals One of the pivotal technologies in human cultural evolution

• Neanderthals had control of fire and used tools, but only modern humans havedomesticated animals and plants

• Products from domesticated animals were more reliable, less laborious anddangerous to obtain, and of better quality than those obtained from the wild

• Domesticated animals have become essential sources of: food (e.g., meat, milk,eggs), clothing (e.g., wool, leather), and hundreds of other commodities (e.g.,makeup, gelatin, fertilizer)

• Domesticated animals are still used in transportation and employed as workanimals in the production of plant crops and other-labor intensive activities

Keeping livestock allows humans to occupy areas where plant cropscould not be produced (e.g., the tundra, deserts)

Consumption of milk by humans provides food without killingvaluable animals and has influenced human evolution (milk-dependent peoples need to be able to digest milk in post-adolescence,i.e., they must be genetically “lactose tolerant”)

As humans evolved culturally, domestic animals took on many newroles, e.g., recreation and entertainment, assisting the disabled

However, domestic animals have spread diseases to native animalsand humans of other cultures, and introduced domestic animals oftenbecome serious pests in outside their natural environments

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Food

BIO 4730/5730 Environmental Biology Topic 6

Sources of Food: LivestockExtremely important sources of food (protein- and lipid-rich

meat, milk, and blood)Ruminants (cattle, goats, sheep, reindeer, camels and llamas)

convert cellulose (Earth’s mostabundant organic compound,but indigestible by humans)into human food Bacterial fermentation and

digestion occurs in multi-chambered stomach

In addition to cellulosebreakdown, there occursamino acid and B-vitaminsynthesis

Bacteria are also digested bythe ruminant as food whenthey reach the abomasum(true stomach)

Environmental Impacts of Livestock ProductionDeforestation Cattle ranching and soybean production for animal feed is a primary

cause of deforestation in the Americas. One quarter- pound hamburger,if the beef is imported from Latin America, potentially requires theclearing of 5 m2 of rainforest and destruction of 75 kg of living things,including 20 to 30 different plant species, 100 insect species, 10s ofvertebrates, and who knows how many others? Since 1960, >25% of all Mesoamerican forests have been cleared for pasture Nearly 70% of deforested land in Panama and Costa Rica is now pasture Some 100,000 km2 of Amazon forest were cleared for cattle ranching and other

commercial development between 1966 and 1983. Brazil estimates 38% of itsrainforest has been destroyed for cattle pasture

Overgrazing Grazing, browsing, and trampling greatly damage or eliminate normal

flora and fauna,decreasing biodiversity Grazing tolerant exotic grasses replace native annual plants Thinning of plant cover and trampling increases wind and water

erosion May great change community structure (e.g., encouragesgrowth of shrubs rather than grasses)

Arid and semiarid lands have low productivity and are vulnerable toovergrazing

Damage to aquatic systems Disruption of water flows Physical damage to riparian zones Animal waste released into water produces eutrophication Exotic

diseases (e.g., rinderpest, hoof-and-mouth)Competition with or predation upon native species Ruminants (especially cattle) destroy riparian species, cause

community changes in plants community composition Swine root up and eat vegetation, eat eggs and young of ground-

nesting birds and reptiles, as well as other animals Poultry eat vegetation and beneficial insects Grazing, browsing, and trampling greatly damage or eliminate

normal flora and fauna, decreasing biodiversity. Grazing-tolerantexotic grasses replace native annual plants, shrub lands increase. Thinning of plant cover and trampling increase wind and water erosion and

may greatly alter community structure. Arid and semiarid lands have low productivity and are particularly

vulnerable

Algal “Blooms” from Nutrient Imbalances“Red Tides” or “Brown Tides”: diatoms and dinoflagellates

Caused by seasonal shifts in nutrient levels (‘algal succession’) Normal patterns disrupted by nutrient imbalances Nutrient runoff from agroecosystems and other pollution into

oceans via rivers (problems often worst in estuaries)Usually exist in a benign form (or in low abundance), but can

be stimulated to produce neurotoxins when nutrient levels arehigh and/or fish secretions are present Water or airborne Algae consumed by filter-feeding animals Some of these toxins can biomagnify in aquatic

food chainsAppear to be increasing in number and effect

About 10 nasty species known 10 years ago,more than 60 known today

Also, many areas never recorded before as havingthese blooms (e.g., Central and South America,Indonesia, New Guinea, and Philippines now have them

Pfiesteria piscicida

Toxic Effects of Algal Blooms Depress appetites of protozoans and molluscs. Kill fishes and marine

mammals More than 1 billion fishes in Chesapeake Bay, Albemarle and Pimlico

Sounds since 1990 14 million fishes off Texas in September 1997 158 (10% of population) of Florida manatees during one 18-month bloom 162 dolphins in Gulf of California Pfiesteria piscicida, a normally benign dinoflagellate discovered in 1988 in

has caused several major fish kills in NC, Chesapeake Bay, and MD– When stimulated by fish secretions it actually chases fish and kills them w/in minutes– People coming into contact with the organism develop oozing sores (like fishes), but also

neurological symptoms (mental impairment and memory loss)– Five such toxins isolated in rat studies

Also cause numerous human illnesses and deaths: Pseudo-nitzchia diatom (amnesic shellfish disease: seizures disorientation,

memory loss, coma) Atlantic, Pacific, and Gulf Coasts) Gynodinium, Alexandrium, Pyrodinium dinoflagellates (paralytic shellfish

poisoning): death w/in 24 h by respiratoryarrest (Alaska to west coast of U.S.) Gynodinium breve dinoflagellate (neurotoxic shellfish poisoning): respiratory

and neurological problems (Texas to North Carolina)

0

2

4

6

8

10

12

Chi

na

Peru

Chi

le

Japa

n

U.S

.

Rus

sia

Indo

nesi

a

Indi

a

Thai

land

Nor

way

S. K

orea

10

30

50

70

90

1950 1960 1970 1980 1990

To

tal

Mar

ine

Fis

h C

atch

(MT

/yr)

Sources of Food: Fisheries

Marine life is increasingly sought for protein Humans first exploited coastal fishes, the result of commercial overfishing is that

many once common species are now commercially extinct “By-catch” (wasted fish or inedible marine life caught along with target species)

has also increased. Up to 90% of biomass caught is wasted, e.g., Sea turtles, jellyfish, etc. caught in shrimp trawls “Shark-fin soup”: rest of shark tossed overboard

(alive) Long lines, gill nets catch seabirds, seals, whales, etc. Reefs are damaged by trawls and anchors (e.g., sea

cucumber fishing, shrimping). Dynamite and cyanideused to collect reef fishes kill corals Cutlassfish are commonly

caught in shrimp nets

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Food

BIO 4730/5730 Environmental Biology Topic 6

Fishing TrendsAs traditional fisheries declined, we exploited other species, such that:Fisheries increasingly exploit species once considered “trash fish” Marketing these has produced amusing “image makeovers” (change the name and don’t

show the whole animal to the consumer!). Bycatch also used in aquaculture andlivestock production

Fisheries have moved farther from the coast 200-mile territorial limits have led to an increase in (often state-sponsored) pelagic

(open ocean) fishing fleets (modern factory ships do not need to return to port except tounload their catch). Coastal fishing communities have suffered severe economic losses

Fishing occurs at increasingly greater depths Decline in epipelagic catches has increased exploitation of

mesopelagic species formerly considered ‘trash fishes’, e.g.,‘orange roughy’, which lives at over 1000 m depth, whereit grows slowly (it lives for 150 years). They are taken in hugenumbers where they congregate around sea mounts (New Zealandstocks have collapsed, Tasmanian stocks are declining)

There is increasing dependence on lower trophic levels Cod (Gadus morhua) literally drove the colonization of

of the New World (for 100s of years it was salted anddried as a provision for ocean voyages: the Vikingsreached N. America ca. 1000 years ago looking for cod). As cod began to disappear, otherspecies (e.g., hake and pollock) replaced them.

Many top predators (e.g., swordfish, tuna, sharks) are depleted. Fishing for lower-levelconsumers (e.g., squids) has increased.

Sources of Food: Aquaculture Provides only a small amount of the world’s food supply Increasingly important protein source for many nations,

especially in Asia and Europe: Mollusks (‘shellfish’): mussels and oysters (worldwide); snails Arthropods: krill and shrimps (including freshwater sp., Asia); crabs;

lobsters and crayfish (U.S.) Fish: carp (China); Tilapia (Africa, Israel, and other counties), trout,

salmon and catfish (U.S.), milkfish, plaice and sole (Great Britain);eels (worldwide); sturgeon (U.S. and FSU); yellowtail tuna (Japan)

Can often be grown in communities, along with edible aquaticplants (e.g., rice), and can control pests In China, leaves from mulberry trees are used to feed silkworms,

leaves and silkworm feces fertilize ponds and grow algae. Algaefeed fish. Fish pond sediment fertilizes mulberry trees

Hot water effluents from power plants can allow year-roundproduction in colder climates

Environmental Impacts of Aquaculture Damage to aquatic systems

Disruption of water flowsPhysical damage to freshwater and coastal

marine ecosystemsOxygen-demanding animal wastes released into

water produces eutrophication Introduction of exotic diseases Introduction of non-native

species Introduction of genetically-

engineered organisms

Sustainable Yields Maximum sustainable yield - amount of a crop produced per

unit area that can be sustained indefinitely withoutdecreasing the ability of the crop to sustain that yield

Optimum sustainable yield - amount of a crop produced perunit area that can be sustained indefinitely withoutdecreasing the ability of the agroecosystem, as well as thecrop, to sustain that yield

Most modern agriculture is not sustainable We have little idea as to how much, or how to improve it Rapid development of crops, food processing, etc. make it difficult

to view this in a controlled context Most environments are not optimal for every crop (or even

one crop) Need fertile soils, lots of sun, moderate temperatures, adequate

rainfall (distributed throughout growing season), etc., etc.

High fossil fuel and water consumptionaccompanies modern food production

Energy investedFood Source Energy in food producedPelagic ‘factory’ fishing 12Feed lot beef 10Fish protein concentrate 6Grass-fed beef 4Coastal fishing 2Intensive poultry production 2Milk from grass-fed cows 1Range-fed beef 0.5Intensive corn or wheat 0.5Intensive rice 0.25Hunting and gathering 0.10Traditional wet-rice culture 0.05Shifting agriculture 0.02

On average, the production of meat costs up to14.7× more energy than that of vegetable foodThe amount of energy in 1 kg veal is the sameas that contained in 100 kg of potatoes (1:100),a normal pasture field producing about 330 kgof meat could yield 40,000 kg of potatoes(1:121 or 20% more calories!)

Producing 1 kg of animal protein requires>111 T of water, about 100× as much asproducing 1 kg of grain protein

Technology Applied to Food ShortagesCan genetic engineering counteract the effects of humanpopulation growth and the environmental degradation thataccompanies more intensive use of arable land?

No selectively-bred or genetically-engineered has everapproached even doubling yieldHuman populations will increases by 75% in the next

century Selectively-bred and genetically-engineered crops are

expensive and difficult to produceOnce successful, they are quickly adopted, and the genetic

diversity of the crop species as a whole tends to decreaseTo protect the companies’ investment, crops are often

engineered so that their seeds are sterile (ensuring that newseed be purchased for each crop)

The overall decrease in genetic diversity increases thelikelihood of epidemic diseases and pest outbreaks

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Food

BIO 4730/5730 Environmental Biology Topic 6

Production of Animal Foods by HumansAt any given moment,

there are 1.3 billioncattle, nearly 1 billionpigs, 1.8 billion sheepand goats, and 13.4billion chickens onEarth

Worldwide, 211 MT ofmeat was produced in1997, a nearly 5×increase since 1950

This is equivalent to36 kg per capita (2× the1950 level)

About 470 MT of raw milk is produced each year: about45% is produced in Europe (60% in Europe and NorthAmerica combined)

Per capita U.S. meat consumption in lbs.(source: American Meat Institute)

Production of Animal Foods in the U.S.In 1999, the U.S. produced >21 MT of meat: 12 MT of beef,

8.8 MT of pork, 106,000 T of veal, and 112,000 T of lamb andmutton

U.S. Poultry production in 1999 was 16.2 MT (13.8 MTchicken, 2.4 MT turkey)

Per capita consumption of meat in the U.S. in 1999 was 235lbs (a record), or 3× theamount produced percapita worldwide, andconsumption of milkproducts, eggs, andseafoods are also ator near record levels

International Trends in Animal Consumption Meat consumption is concentrated in a relatively few countries:

• The U.S., China, Brazil and the 15 EU countriesconsume >60% of the world’s beef, >70% of thepoultry, and >80% of the pork

• Of the 10 most populous nations, five (China, theU.S., Brazil, Russia and Japan) consume meat inquantities ranging from 40 kg (Japan) to 123 kgper capita/year (U.S.), while India, Indonesia,Pakistan, Bangladesh, and Nigeria) each consume<5 kg per capita/year

• Overall, per capita meat consumption is 3× as highin developed countries as in developing countries(people in the U.S. obtain 39% of their caloriesfrom animal sources, compared with 21% forEuropeans), however, increasing affluence in rapidly-industrializing nations(e.g., China) has led to a 2× increase in per capita consumption of beef, pork,and chicken over the past 10 years

Milk consumption also varies widely: highest in Europe and NorthAmerica to lowest in Asia

Besides their own land, most developed countries use large areas ofdeveloping countries for the production of feed (e.g., corn, cassava,soy)

Resource Consumption by Livestock Rangeland: livestock free-range and graze on native and/or introduced

plants: provides food for animals without plowing or sowing (butovergrazing is a problem worldwide)

Pastures: must plow and plant field (can’t grow human food, althoughcrops like alfalfa can recharge soil nitrogen)

Cropland production: grain for animal feed• 43% of the world's grain harvest (735 MT) is fed to livestock (if fed directly to

humans, this would be enough to sustain almost 2.5 billion people, about thenumber that are mal- or undernourished)

• 70% of the grain (mostly corn) produced in the U.S. is used to feed livestock, andmost cattle are entirely grain-fed

• Each bushel of corn requires 1.8 gallons of oil to produce (on average, the productionof meat costs up to 14.7× more energy than that of vegetable food)

• Four kg of vegetable protein (cattle feed) on average yields only 1 kilogram of animalprotein

• Producing one 57-g egg requires 151 g of chicken feed Livestock also require a water source

• Producing 1 kg of animal protein requires >111 T of water, about 100× as much asproducing 1 kg of grain protein

• Goats require less water, but are less efficient milk/meat producers than cattle• Producing one 57-g egg requires 300 g of water

Industrial Livestock Production Some livestock, e.g., pigs, chickens, and ducks, are natural

foragers, making them well-suited for ‘free-range’production• This type of farming is still important in many countries, but has been

overtaken in more developed nations by intensive farming practices(“factory farming”)

Since 1986, the number of U.S. hog producers hasdecreased by 247,500 (72%)• Of the remaining hog operations, 2% have 50% of the hog inventory,

and almost 75% of all pigs are raised on farms with 5,000+ animals• Smithfield Foods is the largest hog producer in the world (12 million

animals/yr: 12% of the US market) and is >3× the size of its nearestcompetitor

Four meat-packing companies control an estimated 79% ofU.S. cattle processing

98% of all poultry is produced by large corporations(Perdue is the largest)

Criticisms of Industrial Food Production Maintenance of animals at high

population densities (100s to 100,000s ofanimals) confined to cages or small spaceswith little or no access to sunlight, freshair or natural movement

Use of hormones, antibiotics, and otherdrugs to control disease and promotefaster growth

Mutilation of animals (e.g., debeakingpoultry, clipping pigs’ tails and pullingtheir teeth, and docking cows’ tails,castrating males, and removing hornswithout anesthesia)

Processing of animals while they arestunned, but alive

“Corporatization” of food production,leading to loss of family farms ordelegation to a subcontractor role, withthe corporation controlling all aspects ofraising the animals, leaving the farmerwith the overhead, waste, and losses fromdead animals

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Food

BIO 4730/5730 Environmental Biology Topic 6

Animal Lovers: Stop Reading NowNasty, brutish, and short: the normal lifespan of cattle is 18-25 yearsBeef Cattle Production: After being weaned by the breeder and spending

their first six months on rangeland, most beefcattle in the U.S. are rounded up and shipped longdistances to feedlots, where they are kept in smallenclosures (about 1.3 m2 of space per animal)• They are “finished” (fattened to market weight

and condition) in another 8 months (range-fedcattle require 3-4 years to finish) by being fed amore- concentrated diet (mostly corn and soy)than grass

• Cattle do not have the stomachs for this rich dietand, without the use of antibiotics, can’t toleratethis type of feed

Once finished, they are stunned with electricity,and killed (one hopes) with a pneumatic hammer

Their throats are then cut, and they are suspended upside down tobleed the carcass

Animal Lovers: Stop Reading Now!The “Veal World”: Male calves born on dairy farms are taken from their mothers and

confined in wooden stalls, tethered by a chain around their neck torestrict movement (to prevent muscle development and speed weightgain)• The calves are maintained in this way for the next 13 to 15 weeks on a low-

iron diet (anemic calves produce pale flesh), and are then slaughteredMilk Production: Dairy cows must be pregnant for them to begin producing milk

• Cattle have the same nine-month gestation period as humans, so dairycows must be made to give birth every year to continue production

Additionally, growth hormones, and milking machines are used toincrease milk production• As a result, many dairy cows are under constant stress, and often develop

health problems, including: metabolic disorders, mastitis, joint disorders,and “milk fever” (hypocalcemia)

• During one lactation cycle, a typical dairy cow’s milk solids total 1.4 to 1.7×her body mass

The lifespan of a dairy cow is 4-6 years

Animal Lovers: Stop Reading Now!Pigs and horses:Factory farmed pigs spend their lives in intensive confinement, often

restricted to a crates that are only 18 to 24 inches wide•Pigs are as intelligent as dogs, and under these conditions, they bite each other,

generally each other's tails (to prevent this, farmers cut off their tails and pull theirteeth, and boars’ noses are broken to keep them from fighting)

Sows are artificially inseminated when they are 6-8 months old.Pregnancy lasts about 4 months, yielding litter of about 12 piglets

•Sows are natural nest builders, but must tend their young in a pen on a bare cementfloor. The piglets remain with their mothers for a only a few weeks. They are thentaken from her and she is impregnated again, producing five to eight more littersbefore slaughter.

•The natural lifespan of a pig is 10-15 years. Brood sows generally live for 3 to 4 years.Most pigs live only a few months before being slaughtered.

Although illegal in the U.S., horsemeat is still eaten in many parts ofthe world (e.g., in France)

•About 62,000 horses are slaughtered in the U.S. each year for human consumption,mostly for the European market (another 25,000 are exported to Canada for slaughter)

•Many of these are riding or race horses no longer wanted by their owners•About 40,000 foals born each year to mares producing PMU (a source of estrogen

used to make Premarin) are also sold for slaughter

Animal Lovers: Stop Reading Now!Poultry Production: 100s to 10,000s of chickens and turkeys live amid dust, feces, and high

levels of methane and ammonia fumes All aspects of their environment (lighting, amount of food and water)

are controlled in order to make them grow faster on less feed• Crowded conditions cause fighting, with birds pecking at, and sometimes

killing and eating, each other (to prevent this, the birds are “debeaked”:the distal end of the beak is cut off)

“Free-range” chickens (allowed to roam freely) and their eggs are oftena marketing hype• The “USDA requires only that growers sign an affidavit that they will

provide free-range chickens with access to the outdoors, and submitdrawings or photographs with arrows pointing to the coops’ doors… … ‘Ifthe door was open only one day . . . or maybe even for an hour or 15minutes, and no bird chose to go outside, it’s still free-range as far as theUSDA is concerned.’” (Consumer Reports)

Americans like white meat, so chicken and turkey legs are primarilysold to Russia. The feet are sold to the Chinese for soup. Feathers areconverted into animal feed

Animal Lovers: Stop Reading Now!Egg Production: A shed of laying hens may contain 250,000 birds or more

• Laying hens are crammed into stacked tiers of cages about 1 foot square: three tonine birds to a cage

• The cages have a sloping wire floor to collect the eggs, but this cuts into anddeforms the hens feet and makes it uncomfortable for them to stand (the skin ofthe hens’ feet frequently grows around the metal wiring). Their wings are alsorubbed raw by the wire walls

240 million laying hens produce about 50 billion eggs each year in theUnited States (laying hens commonly lay 300 or more eggs in a year)• At this point, they may be killed and sold as food or fed back to the flock• Alternatively, they are given in a “forced molt” treatment, in which they are

deprived of light and food for one to two weeks, to get them to resume laying(1/3 do not survive this process)

Male chicks are of no use and are discarded or converted into feed• About 400 million per year are thrown in garbage bags, gassed with CO2, and

crushed or ground (sometimes alive) into feed The natural lifespan of a chicken ranges from 7-20 years. Laying hens

live about 18 months, and broilers for seven weeks

Are Factory Farms “Better”? The cost per unit for large commercial operations is no better in larger

than in family farms• The optimum efficiency for raising hogs is attained on a “farrow-to-finish”

operation of only 150 sows Factory farms add many hidden costs through increased use of fossil

fuels, drugs, environmental damage, and health threats• In general, hog factories displace three times as many jobs as they create,

while smaller farms generate a higher number of permanent jobs, a greaterreduction in unemployment rate, and account for a greater increase in localsales per capita income than hog factories

Specialization by factory producers on a few strains (which in thefuture may be predominant;y genetically-engineered stock) acceleratesdeclines in family farms that breed heritage livestock:• Threatens fertility as livestock are increasingly inbred• Results in the loss of genetic diversity, potentially increasing the threat of

epidemic diseases Large, concentrated livestock operations would be an attractive target

for terrorists• Many livestock diseases are highly communicable, easy to transfer and

administer, and not infectious to humans

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Food

BIO 4730/5730 Environmental Biology Topic 6

Crop Production Only the U.S., Canada, Australia, Argentina,

and New Zealand are net exporters of crops,the rest of world’s nations are net importers

Total world grain production about 1.5 billionT/yr

Developing countries (with half the world’spopulation) produce only 400 million T of this

Great increase in grain production in 20thcenturyGrain production nearly doubled (631 million to

1.237 billion T) between 1950-1971 aloneRate of increase in production has since declined

Measures of Food AvailabilitySupply of grain on hand, measured in days

Famines decrease the supply even more U.S. has more then 1/2 the world’s surplus grain and 4 MT for

emergency relief Sufficient stockpile to prevent shortages would be about 10-20 MT

or about $2 billion. Maintaining this would cost about $200million/year

Per capita food production Both population and food supply have increased, with rate of food

increase more variable No average increase in availability

Per capita demand - economic demand per person Demand for food - the amount of food that would be bought at a

given price if it were available. Increases with population and per-capita income

Demand for variety increases along with amount

Food Production and Availability Great increase in human population has driven an

equivalent increase in food demand Demand exceeds production in most places Inadequate distribution networks aggravate problem

Food production depends on environment: amount of andvariability in sunlight, temperature, moisture, pests

World food supply is influenced by social disruptions andattitudes, which affect the environment and in turn affectagriculture

Agriculture changes the environment: solutions toenvironmental problems can create new onesOf all human activities, agriculture has by far the greatesteffect on the environment: possibly more than all othereffects combined

Ways to Increase Food Supply New crops - replacement of existing crops with species better-

adapted to local conditions Genetic engineering - development of new food organisms

(e.g., self-fertilizing or pesticide resistant strains) Irrigation - increases yields, but could be much more efficient

and waste less water Drip irrigation - wastes less water, but expensive to set up

Increase amount of agricultural land More use of marginal lands (alone or w/ new crops or strains) Hydroponics -grow crops indoors in water- and nutrient-filled tanks

Eat lower on the food chain Improve food distribution

In many places, inefficient distribution and/or low incomes, are theproblem, not production

Limits to Food ProductionEven with new crops, genetic engineering, morefertilizer and water, there is a limit to food productionon Earth

If populations continue to grow at present rates, foodproduction must double or triple by 2010 for all people to befed Many crops are already at their maximum production from fertilizer

application Increases must therefore come from new higher producing crops or

“superstrains” of existing ones that do not yet exist Climate change is more likely to decrease than to increase

yields Areas with the best soils also have the best climates for agriculture.

Changing this climate (or increasing its variability) will decreaseyields, as will shifting crops to poorer soils

Water supply and infrastructure, transport, etc. all will have to bechanged

Realistic Ways to Stretch the Food SupplyEat lower on the food chain Improve food distribution Improved irrigation to waste less water and reduce

salinization Increase production in sustainable

ways, including development of“new foods”: replacing existingcrops or livestock with species thatare better-suited to local conditions

Genetic engineering (butemphasizing development ofself-fertilizing strains overpesticide-resistant ones)

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Food

BIO 4730/5730 Environmental Biology Topic 6

Substitutes for Animal Foods

soybeans

grains andvegetables

fungi

Vegan DietsLower cholesterol and fat, higher-fiber vegan dietresults in decreased risk of some illnesses:including heart disease, diabetes, obesity, andcolon cancerDecrease in wasted energy when producingfoodDecreased ecological impact whenproducing foodDecreased exposure to growth hormonesand antibiotics used in production ofanimal foodsDecreased exposure to some bacterial (e.g., E. coli) and viral (e.g., hepatitis inshellfish) diseases. No known exposure to prion (“mad cow”) diesases.Decreased exposure to biomagnified toxicants (e.g., metals, PCBs)No ‘animal cruelty’ involved in producing your food

Care must be taken to ensure diet is complete (all 20 amino acids, essentialfatty acids, vitamins and minerals), especially when pregnantRestricts dietary choices (e.g., at many restaurants)No more hot fudge sundaes! Ever!