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Teacher Guide ContentsBackground Information . . . . . . . . . . . 2

Activity Plan . . . . . . . . . . . . . . . . . . . . 5Reproducible Blackline Masters . . . . . . 9Additional Teacher Resources. . . . . . . 12

Milk from Cow to YouProgram Componentss Teacher Guides Posters Student Handouts

Program ObjectivesThe Milk from Cow to Youprogram

has been designed to help studentsachieve several objectives including:

s Understanding the importanceof dairy products in the diet

s Understanding the steps inproducing/processing milk

s Describing the safeguards forkeeping milk fresh and clean

s Recognizing interesting factsabout cows

Breeds of CowsThere are nearly10 million milk cows inthe U.S. today. About 90% of them areHolsteins. The major breeds are:

s Holsteins (black and white)s Jerseys (yellowish-brown)s Guernseys (tan and white)s Brown Swiss (dark brown or gray)s Ayrshire (white with reddish spots)

Vital StatisticsCows are large animals.The following statistics are givenfor the average Holstein:

Gender FemaleHeight 5512 feet

Weight 1400 lbsBody temperature 101.5F

Weight of udder 2560 lbs

Amount of milkheld in the udder 2550 lbsAverage herd size 5075 cows

Vo-Cow-Bulary

CudFood swallowed by the cow but notchewed thoroughly until later

Dry OffPeriod when cow is not being milked

HomogenizeTo blend milk so that butterfat particlesare evenly distributed throughout

Let Down

Condition when cow is ready to bemilked because the teats are filledwith milk

PasteurizeTo heat milk to a high temperaturefor a short time to protect its purity

SilageA chopped mixture of green corn,grass, and legumes stored in a silo

TeatOne of the 4 nipples on the cows udder

where milk comes out

UdderPart of the cow where milk is stored

TEACHERS BACKGROUND INFORMATION

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0324NNATIONAL DAIRY COUNCIL, Rosemont, IL 60018-5616.

All rights reserved. Printed in the U.S.A.

3 2004, Copyright 1995, 2nd edition.


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Bovine Eating HabitsCows are big eaters. Each day,

they eat approximately:s 40 lbs. feed and hays 50 lbs. silages 2550 gallons water

nearly a bathtub full!

Ninety pounds of food equals480 hamburgers. In comparison,the average American eats onlyabout 4 pounds of food a day.

A 4-Part StomachCows have a unique digestive system:

s Cows swallow food quickly withoutchewing it well.

s The food goes into the first andsecond stomachsthe rumen andthe reticulum.

s When the cow has eaten her fill, sheburps up a small amount of foodcudto chew again.

s After chewing her cud thoroughly,she swallows it and it goes into the3rd stomachthe omasum.

s From there it moves on to the4th stomachthe abomasum

where digestion actually occurs.s Cows spend about 612 hours

a day eating.s A cows body uses part of the food

to grow and stay healthy. Her bodyuses another part of the food to

make milk in the udder.s It takes the cows body about 2 days

to process her food into milk.

Cows as Milk ProducersCows have been called natures own

milk factory on four hooves.s All cows are females. Like humans,

they cannot produce milk until theygive birth.

s Cows usually have their first calfwhen they are 2 years old. Thegestation time for a calf is 9 months.9597% of the pregnancies resultin one calf.

s Cows are usually milked for 305days (10 months) after giving birth.

s Then they are allowed to dry offfor about 2 months until their nextcalf is born.

s To dry off a cow, the farmer stopsmilking her. This gives her body thecue to stop producing more milk.

s Most cows are milked for about7 years.

Each well-fed cow produces an averageof about:

s 25 pounds (45 cups) of milk inone milking.

s 50 pounds (90 cups) of milk per day.s 15,000 pounds (28,000 cups) of

milk in a year.s 107,000 pounds (200,000 cups)

of milk in a lifetime. Thats enoughto fill the average classroom 2 feetdeep with milk.

If a cow eats only grass, it producesonly about13.3 pounds (24 cups) ofmilk in one milking. So you can see,good nutrition pays off for cows as

well as people!

Milking CowsCows respond best to patient,

kind handling and regular, routineprocedures. They are milked 2 or3 times a day.

First, the cows udder and teats arewashed before she is milked. This isdone to:

s Keep the milk clean.s Send a signal to her brain to

let down the milk.

Then a milking machine is attached to

the cows 4 teats.s The milking machine doesnt hurt

the cow.s The vacuum of the milking machine

gently squeezes out the milksimilar to the action of a suckingcalf or a baby sucking his thumb.

s It takes about 5 minutes to milka cow.

s On many farms, computers keeptrack of how much milk a cowproduces at each milking.

s The first milking machine waspatented in1894. With milkingmachines farmers can milk about100 cows an hour.

s Before then, cows were milkedby hand. A farmer could milk about6 cows an hour by hand.

s If a cow misses a milking, the milkbuilds up in her udder. She will havelots of milk in her next milking andmight even begin to leak.

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Storing MilkOnce outside the cow, milk is

never exposed to air because it hasno protection from contaminants.That is why clean equipment andsanitation are so important.

Pump It

s Sanitized pipelines carry milkstraight from the cow and milkingmachine to the cooler.

s Milk is never touched byhuman hands.

Cool It

s Milk comes out of the cow warmat the cows body temperature.

s It is quickly cooled in refrigeratedstorage tanks to 45F or lower tokeep it fresh and good tasting.

s Milk is stored in the refrigeratedtank until the tank truck comes.

s Tank trucks come every day ortwo to pick up the milk.

s Milk is pumped into the insulatedtank truckwhich is like a giantThermos bottle on wheels.

s The tank truck keeps milk freshand cold on its way to the dairyprocessing plant.

At the Processing PlantMilk samples are first tested in a lab to

ensure that only the purest milk is used.Milk that isnt top quality or that hasntbeen kept cold enough is not processedfor people to drink.

Homogenize

s The milk is then homogenized tobreak the butterfat particles intotiny, uniform globules.

s Homogenizing ensures that thebutterfat particles are uniformly

distributed throughout the milk.s If milk wasnt homogenized,

the cream would rise to the top.So you would have to shake orstir the milk before serving.

Pasteurize

s In 1856, Louis Pasteur, a Frenchscientist, discovered that heatingliquids to high temperatureskills bacteria.

s Today, milk is pasteurized by quicklyheating it to161F for 15 secondsand then rapidly cooling it.

s Pasteurization protects the purityand flavor of milk without affectingits nutrient value.

Milk is made into a variety of products,including:

s White and chocolate milks Buttermilk

s Cheeses Cottage cheeses Yogurts Ice cream and frozen yogurts Butters Cream, sour cream, and

whipped cream

At the GroceryIt takes about 2 days from the time milk

leaves the cow until the time it reachesthe grocery store. At the grocery, milkis kept refrigerated at 40F or lower.

Handling Milk at HomeConsumers can help keep milk pure andsafe by following the 3 Cs:Keep milkcleanKeep milkcoveredKeep milkcold

s Store milk in its own container orin a clean pitcher. Do not touch thepouring lip of the container.

s Keep the milk container coveredor resealed when done pouring.Milk quickly picks up flavors ofother foods in the refrigerator.

s Because milk is perishable, it mustbe refrigerated at 40F or colder.Store milk in the coldest part of

your refrigerator.

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What MilkDoes for YouOne delicious cup ofice cold milk provides:

%Daily

Value

30% calciumfor strong bones and teeth

24% riboflavinfor healthy skin

16% proteinto build strong muscles

10% vitamin Afor night vision

Students age 6 to 10 need at least3 servings from the Milk Groupeach day to get the nutrientsthey need.

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