Activities for Module III Fur, Feathers, and Fins
- Animals in our food
Activities for Section C: Animals
in the Agro-ecosystem
1: Water and Numbers
Part 1. How much water does it take to produce
a pound of beef?
Part 2. How much water do you use at home?
Part 3. Concluding discussion
Purpose: Students will explore
the impacts of animal agriculture on water, consider
regional differences in water use, and begin thinking
critically about statistics.
Part 1. Print out the Part 1 handout. Make enough
copies for all the small groups.
Part 2. Print out the chart for estimating water
use from National Geographic water use calculator and make copies. Ask students to bring in copies
of their water bills if they are on public water
Part 3. Print out “Water Facts and Figures”
Estimated time: Part 1: 20 minutes,
Part 2: 30 minutes, Part 3 (concluding discussion):
Background information: One
common criticism of meat production is that it
uses a lot of water compared to other agricultural
Estimates of how much water meat production takes
vary widely, but even conservative estimates make
beef a pretty water-intensive food.
Part 1: How much water does
it take to produce a pound of beef?
Divide the students into small groups. Give each
group the three water use estimates. Have each
group discuss and answer the questions in this
worksheet (MS Word document).
Key to discussion questions in above worksheet
- Which calculation do you think is
the right one?
All three estimates may be roughly
valid, since they are measuring different things.
It depends on how they are used.
- What difference does it make whether
the water to grow the feed comes from rainfall
If the water comes directly from rainfall,
then how it acts in the environment is not
changed that much by the fact it is helping
food for cattle to grow, especially if the
food is well managed pasture, not treated
with fertilizers or pesticides. If the water
is irrigation water, then its use will have
much greater environmental impacts.
Much of the forage and grain fed to beef
produced in the western US is grown using
irrigation. Some of this irrigation water
is pumped from aquifers at unsustainable rates.
Some is diverted from river systems, altering
aquatic communities and reducing the water
available for other uses. For example about
85% of the water taken from the Colorado River
in California, Arizona, and Nevada is used
for agricultural purposes. Long before the
Colorado River reaches its historic outlet
to the ocean in Mexico, it has completely
dried up, because its natural flow has been
diverted for agricultural use. Some of the
water withdrawn goes to fruit and vegetable
production, but livestock production is a
major water user (see Land Use History of North America)
In Wisconsin and Iowa, in most years rainfall
is adequate for forage production, and very
few farmers irrigate pastures, hayfields,
or feed crops. However, farmers do withdraw
water from streams and wells to provide drinking
water for their animals, as well as water
for washing milkrooms and other animal production
facilities. This agricultural use can have
impacts on some local water supplies or aquatic
Does it matter how the irrigation is
handled? Why and how?
How the irrigation is handled matters a lot.
For the environment it matters how much water
is withdrawn from natural water courses and
how efficiently the water is used. For example,
if half the water is lost in transport (not
uncommon), then actually double the amount of
water used for irrigation had to be taken away
from a river or stream. If the irrigation water
is applied in the same small watershed that
it was taken from, at least some of it will
be returned to the river or stream. If it is
applied in a different watershed, all the water
is lost to the original water source. It also
matters for social reasons. For example if upstream
users take all the water they want, there may
be none left for downstream users.
- Why do you think the Cattlemen’s
association publicizes the figure of 435 gallons?
Why do many environmental organizations use
the higher figure estimated by Pimentel? Why
does it matter how much water it takes to produce
a pound of beef?
The National Cattlemen’s Beef Association
wants people to think that beef production is
environmentally benign, so they choose the lowest
estimate. In addition, the association may wish
to protect certain regional interests. Using
a national average obscures the differences
in environmental impact caused both by geography
and by the production system.
Environmental organizations want people to
realize how high the environmental costs of
beef production can be, so they use the higher
figure. Unfortunately, by doing so, they imply
that all beef production has a level of environmental
impact that in fact only some producers have.
The amount of water used in beef production
is important when it has negative impacts
on the environment or on access to water for
other uses. Of course, livestock production
can damage the environment in other ways than
- These estimates were all calculated
at least ten years ago. Do you think water requirements
for beef production have changed? Why or why
Since there are no newer estimates, we can’t
be sure whether or how water use for beef production
has changed. However, it is likely that it has
not changed much, if at all. Agriculture’s
use of water for irrigation has been fairly
stable over the last 10 years, though there
are some annual fluctuations due to weather.
While there have been some improvements in irrigation
technology, there has also been an increase
in the acreage under irrigation, perhaps due
to climate change. (See USGS estimates)
Part 2: How much water do you
use at home?
The purpose of this part of the activity is two-fold:
First, students will get a sense of household
use of water, which they can then compare to agricultural
water use, and especially that needed for beef
production. Second, students will realize how
difficult it is to estimate water use, and how
much use varies.
Have students use the water bill information to compute average weekly household use. (Take number of days covered by billing period and divide by 7 to get the number of weeks in the billing period. Then take the figure for total water use and divide that by the number of weeks in the billing period.) Compare the information on the water bills with the students' estimates from the water use charts.
Note that the estimated amounts on the chart
make assumptions about the efficiency of appliances
and about how people use them. If students have
better information about their own household appliances,
they can use the more accurate information.
Have students use the water bill information
to compute average weekly household use. (Take
number of days covered by billing period and
divide by 7 to get the number of weeks in the
period. Then take the figure for total water
use and divide that by the number of weeks in
billing period.) Compare the information on the
water bills with the students’ estimates
from the water use charts.
Down the Drain Project personal water use chart provides
guidance for estimating your water use and
comparing it to other students, mostly
in the US.
Part 3. Concluding discussion
Share the water facts and figures with the students.
Discuss the questions from Part 1 of this activity
with the class, along with the questions below,
in light of what students learned from doing their
own water use assessment and in light of the information
in the water facts and figures.
How does use of water for beef production
compare with other food production? With other
Even using a more conservative estimate, beef
is an intensive water user compared to other foods.
However, where and how the beef is raised can
make an important difference in how much water
Although industry uses water too, agriculture
accounts for more use, and unlike industry, most
agricultural use is not returned to the same watercourse.
What can we learn about numbers and statistics
from this exercise?
First, it is not easy to generate accurate statistics.
Second, averages obscure significant variations.
Third, it is important to know what assumptions
were made in generating a number in order to know
how that number should be used.
How could you design a beef production
system that would have relatively little impact
on water supplies?
A system that relies on non-irrigated pasture
and feed will have comparatively little impact
on water in the environment and water supplies.
Water Facts and Figures
According to the American Water Works Association:
The average US household uses about 127,000 gals
water / year. About 40% or 50,800 gals are used
indoors. The rest is used outdoors. The average
US individual uses around 100 to 180 gallons per
day. (Average use tends to be higher in dry areas,
mainly because of landscape watering.)
- In households not utilizing water-efficient
fixtures, toilets used the most water on a daily
basis (20.1 gallons per person per day). Clothes
washers were the second largest water users
(15 gallons per person per day) and showers
were third (13.3 gallons per person day).
- In households that utilized water-efficient
fixtures, clothes washers assume the role of
top water user (15 gallons per capita per day),
followed by faucets (10.9 gallons per capita
per day), showers (10 gallons per capita per
day) and toilets (9.6 gallons per capita per
day). NOTE: The REUWS study group did not contain
a significant number of homes with water conserving
How is Most Freshwater in the US Used?
In 2000, about 346,000 million gallons per day
of fresh water was withdrawn from our surface-
and ground-water sources, such as rivers, lakes,
reservoirs, and wells. Two uses, irrigation and
thermoelectric-power production, accounted for
about 79 percent of water used in 2000. Here's
the breakdown by water-use category:
- Irrigation: 40 percent
- Thermoelectric power: 39 percent
- Public Supply: 13 percent
- Industry: 5 percent
- Livestock, aquaculture: less than 1 percent
- Domestic (self-supplied): 1 percent
- Mining: 1 percent
The large amount of water used for power production
(electricity) is mostly used to cool the heated
power-production equipment. The vast majority
of the water used by power plants is returned
to the environment, and thus is available for
other uses. In contrast, irrigation water is
available for other uses.
In Wisconsin, however, the breakdown of water
use is a little different:
- Thermoelectric: 79 percent
Industrial: 8 percent
Domestic: 4 percent
Agricultural Irrigation: 3 percent
Public Use: 2 percent
Non-irrigation Agriculture: 2 percent
Commercial: 2 percent
(Source: Implementing the Great Lakes Compact: Wisconsin Conservation
and Efficiency Measures Report, UW-Madison Dept. of Urban and Regional
Planning, p. 4, accessed March 2010 at http://urpl.wisc.edu/people/genskow/URPLconservationefficiency2009.pdf )
(US Geological Survey)
The average American individual uses 80 to 100
gallons of water at home each day.
The average individual from Uganda or Ethiopia uses less than 5 gallons
of water each day
(statistics taken from U.S. Geological Survey water facts website
and page 34 of the 2006 UN Human Development Report “Beyond scarcity: Power, poverty, and the global water crisis."
Water required to produce one pound (lb.)
of California foods:
- 1 lb. lettuce: 23 gallons
- 1 lb. tomatoes: 24 gallons
- 1 lb. wheat: 25 gallon
- 1 lb. carrots: 33 gallons
- 1 lb. apples: 49 gallons
- 1 lb. chicken: 815 gallons
- 1 lb. pork: 1,630 gallons
- 1 lb. beef: 5,214 gallons
(according to Soil and Water specialists, Univ.
of Calif. Agricultural Extension, working with
livestock farm advisors Schulbach, Herb , et.
al., Soil and Water, No. 38, Fall 1978, retrieved
from Food Revolution.
"The conclusion of a 2000 report by the
World Commission on Water predicts that the increase
in water use in the future due to rising population
numbers will 'impose intolerable stresses on the
environment, leading not only to a loss of biodiversity
(species extinction), but also to a vicious circle
in which the stresses on the ecosystem (will)
no longer provide the services for plants and
people." ("A Water Secure World: Vision
for Water, Life, and the Environment," Reported
in Mittelstaedt, Martin, "World Water Use
to Soar to Crisis Levels, Study Says," The
Globe and Mail, March 14, 2000)
"In California, the single biggest consumer
of water is not Los Angeles. It is not the oil
and chemicals or defense industries. Nor is it
the fields of grapes and tomatoes. It is irrigated
pasture: grass grown in a near-desert climate
for cows... The West's water crisis --- and many
of its environmental problems as well --- can
be summed up, implausible as this may seem, in
a single word: livestock."
(From Cadillac Desert by Marc Reisner)
"Nearly half the water consumed in this
country is used for livestock, mostly cattle."
(Audubon Magazine, Dec. 1999)
2. Ecological pawprint analysis
Purpose: Students will apply
the ecosystem concepts they have learned to animals
in their own lives. .
Estimated time: 15 to 20 minutes
Place students in small groups, making sure each
group includes at least one student who has one
or more pets. Use the four agro-ecosystem questions
to evaluate the ecological impact of their pets:
Where do key nutrients come from?
What does the pet eat? Where does the food come
from? What happens to the pet’s waste?
What are the sources and sinks of pollutants
in this system?
Does the pet cause pollution? What is the cumulative
impact of dog and cat feces in this community?
What about in different types of communities (urban,
rural)? What is the recommended method of disposal
of pet wastes? What are the impacts of this method
of disposal? What about pest management, medications,
and grooming products for your pet? Do these products
get into the environment?
How do the living organisms in the system
How does the pet affect diversity? Does it hunt?
Do escapees of its kind hunt or displace native
species? How was it bred? (Some exotic fish, reptiles,
and birds are caught in the wild and such exotic
pet trade can put added pressure on rare species.)
What are the energy flows?
Does the pet require extra consumption of fossil
fuel? (Think about producing, processing, and
transporting its food, waste disposal, transportation
costs for large animals such as horses, heating
Have students discuss possible ways the ecology
of pet management could be improved.
*Note that the Animal Protection Institute report
on pet foods suggests that using processed slaughterhouse
waste for pet food is a bad thing. However, from
a nutrient cycling point of view, it is better
than disposing of those wastes in a landfill and
using premium meats to feed pets. Also, unprocessed
meat would require refrigeration, using more fossil
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