1 “this…is the world that has been pulled over your eyes to blind you from the truth.“ -...
TRANSCRIPT
Ch. 9 Food and Agriculture
1
“This…is the world that has been pulled over your eyes to blind you from the truth.“
- Morpheus, the Matrix (1999)
Producing enough food has become a greater challenge as the human population reaches passes 7 billion.
Food energy is measured in calories.Undernutrition occurs when someone does not
eat enough calories (2200 kcal* is the norm).Adults need on average 1000 calories per day to simply
survive.Average of 2200 calories needed for a normal, healthy
life.
*kcal vs “cal”2
Feeding the World
3
3 Types of Nutrients
Chronic Hunger and Food SecurityAbout 925 million people are considered
chronically undernourished or malnourished.Most of these are in developing countries.This is about 13% of the world’s population.Poverty is the greatest threat to food security -
ability to obtain sufficient food on a daily basis.Theoretically, there should be enough food to supply
about 3000 kcal/day to everyone.
4
NUTRITION AND FOOD SUPPLIES
5
Hunger Around the World
A famine is when large-scale undernourishment occurs in a population.Most of the population is eating less than the
daily minimum calories needed (1000 calories)Drought causes more than half of famines.
Other significant causes: war and bad governance.Ex: North Korea was reluctant to request foreign
assistance after severe flooding in the 1990s.
6
Famines
Aid from rich countries often can help alleviate famines in the short term.Drawbacks to foreign assistance:
Population must crowd together in “food camps” to receive supplies.Lack of sanitationQuick spread of diseases
Foreign aid tends to be short-lived as people’s attention moves elsewhere.Ex: Indonesian tsunami of 2004, Hurricane Katrina of
2005, Haiti earthquake of 2009, Pakistan floods of 2010
7
Famines and Foreign Aid
8
Australia Drought of 2006-2009
9
Australia Drought of 2006-2009
10
Australia Drought of 2006-2009
11
Australia Drought of 2006-2009
Malnourishment - nutritional imbalance caused by a lack of specific dietary components or an inability to absorb or utilize essential nutrients3 billion people suffer from vitamin,
mineral or protein deficiency.Results in illness, reduced mental
capacity, developmental abnormality, stunted growth, death
12
We Need the Right Kinds of Food
Undernutrition – Insufficient caloric intake.Malnutrition - Nutritional imbalance caused by
lack of specific dietary components.Overnutrition – A daily intake of calories that is
too high, leading to obesity.The most common dietary problem in wealthy
countries.Up to 64% of all adult Americans are overweight.
13
Types of Malnutrition
Iron deficiency is the most common dietary imbalance in the world.Leads to anemia – insufficient oxygen
transported to the brain, muscles, and organs due to low red blood cell count.Symptoms include fatigue, dizziness, headacheIncreases risk of death in childbirth
Good sources of iron: Red meat, eggs, beans, and some green vegetables (spinach, broccoli)
14
Malnutrition Examples
Iodine deficiency is another very common type of malnutrition, especially in rural developing areas. Iodine is required for
production of thyroid hormones, which control the body’s rate of metabolism.
Chronic lack of iodine can slow all parts of normal development, including body size and brain function.
Lack of iodine can also cause a goiter, or a swollen thyroid gland.
Good sources of iodine: seafood and plant crops from iodine rich soils.
15
Malnutrition Examples
Source: Miller Environmental Science, 13th Edition
16
Protein Deficiency DiseasesKwashiorkor - occurs
mainly in children whose diet lacks high-quality proteinReddish-orange hair,
bloated stomach
Marasmus - “To Waste Away” - caused by a diet low in protein and caloriesVery thin, shriveled
People in rich countries eat too much meat, salt, sugar and saturated fat and not enough fiber, vitamins, and minerals.
On average, we consume 33% more calories than we need.62% of Americans are overweight.
Obesity is spreading around the world as other people adopt Western lifestyles.
17
Overnutrition
Overnutrition
An estimated 90% of the world’s food calories come from 14 species of plants.
Three of those crops deliver a majority of world’s nutrients: wheat, corn, and rice.Main nutrient component of these foods is
carbohydrates.The major food staples are all plants.
Cheaper and easier to produce.Why? Remember the energy pyramid?
19
9.2 KEY FOOD SOURCES
20
Ecological Energy Pyramid
21
World Food Production
Meat and dairy products are all high in protein, iron, and come from animals.As incomes rise in developing countries, food
choices shift towards higher-quality and more expensive foods.60% of production occurs in lesser developed
countries.
Meat requires a high amount of grain to produce.15 pounds of grain to produce 1 pound of meat.CAFO’s – concentrated animal feeding operations. Produce tremendous amount of waste. Requires constant antibiotics.
22
Meat and Dairy
Much of the food produced in the developed world is the result of industrialized agriculture.Dependent on the use of heavy equipment, fuel,
fertilizers, pesticides, and irrigation.Most food is grown as a monoculture, or single-
crop farming.
23
Industrialized Agriculture
Factory Farming and LivestockThe industrialization of agriculture applies to
the raising of livestock, both for meat and dairy.The traditional method of raising animals in
open pasture is now largely a relic of the past, replaced by highly-mechanized large-scale operations.
24
Dairy cows are special breeds chosen for high milk production.
About half of the U.S. dairy cows are raised in confined indoor pens.
As with other mammals, cows only produce milk for about 10 months after giving birth.Must be continuously impregnated to continue
milk production.Female calves are kept within the herdMale calves are usually sent to veal crates.
25
Dairy Production
The advantage of raising dairy cattle indoors is that all aspects of their growth, feeding, and behavior can be monitored and controlled.Cows leave their pens twice a day to be milked
mechanically.
26
Dairy Production
The disadvantage is the rapid spread of disease due to the crowding and high amounts of waste manure.
To prevent this, antibiotics are commonly administered to the cattle.Nearly half of all antibiotics used in the U.S. are
used in farm animals.Farms may also inject their cattle with Bovine
Growth Hormone (BGH) to increase milk production.
27
Dairy Production
There are significant consequences to the use of additive hormones and antibiotics in cattle feed.
Overuse of antibiotics is increases the risk of bacteria evolving resistance to the antibiotic. When this occurs, the antibiotic becomes unusable.
The use of BGH has multiple effects:The overall health of the cows is affected:
Increased likeliness of mastitis (infection of the udders)Increased rate of lamenessReduced fertility
There are also effects on the milk itself:Increased growth hormone in the milkIncreased pus in the milk, causing it to go sour more
quickly 28
Antibiotics and Hormones
Layer Hens – Egg ProductionThe majority of hens (~95%) that supply eggs are
raised in battery cages.These are small cages with slanted floors to drain waste.Hens are confined within small cages their entire life.USDA recommendations for cage size:
Cages are usually 16 inches wide and contain 4 hens.
The highly restricted movement of the hens leads to unusually aggressive behaviors.Beaks are cut or seared off to prevent fighting. 29
Layer Chickens – Egg ProductionChicks that are hatched are sorted by gender;
females are kept; the males are killed and discarded.
The layer hens are subject to near constant light to encourage greater egg production.
Fatigue and mineral depletion are common .Egg production begins to decline when the hens
reach about 12 months.At this point they are slaughtered and used in
processed foods (soup, flavoring, pet foods, etc)The use of antibiotics and growth hormones is
illegal in all poultry.
30
Broiler hens are chickens bred and raised specifically for meat.They have much larger thighs and breasts than
normal; making them very heavy and often unable to stand or walk normally.
Broiler chickens are raised in pens instead of cages to prevent bruising.Beaks and toes are removed to prevent fighting.
The chickens reach their slaughter weight in about 2 months.
31
Broiler Hens
32
Broiler Pens
Pigs are very sensitive animals, prone to sunburn and heat stress.
As a result, they are primarily raised indoors in temperature-controlled “hatch pens”.
Tails are usually cut off at birth to prevent biting – a common issue in overcrowded pens.
33
Pigs
34
Pig Batch Pens
35
Food Additives
The factory farming process makes food much cheaper than conventional methods.
One big downside is an increase in the number of food recalls.
2010 Recalls228 million eggs ( Salmonella )
2009 RecallsNestle Toll House cookie dough ( E.coli )Pistachios ( Salmonella )Products containing peanut butter / paste ( Salmonella
)2008 Recalls
Beef recall ( cattle were not inspected properly )Maple Leaf brand deli meats ( listeriosis ) 37
The Hidden Costs
Cage FreeChickens are not kept
within cages, but may still be high-density indoor pens.
Certified HumaneChickens are uncaged and
“must be able to perform natural behaviors such as nesting”.
Free RangeAnimals are kept outdoors
and allowed to roam.
38
Alternative Production MethodsOrganic
No unnatural feeds or feed additives given to animals.
No additives in the final product.
Does not address treatment of animals
Seafood is the biggest protein source in many island and coastal countries.Annual catches of ocean
fish rose by 4% annually between 1950-1988.
Many areas of ocean are now so overharvested that large-scale fishing is unsustainable.
If current practices continue, the world’s fisheries will be exhausted by 2048.
Nearly half of seafood harvested is now farmed. 39
Seafood
Aquaculture supplies food, but ituses wild populations to stock and feed
captive populationsdestroys mangrove forests and wetlands
used as nurseries for all marine speciesallows the spread of diseasereleases large quantities of feces,
antibiotics and other pollutants
40
Seafood
41
Food Consumption Differences
42
Food Consumptions Differences
43
World Food Consumption