Description of a process. Final work for Passive voice unit

2. Dairy cows typically spend their days eating, sleeping,
and ruminating or chewing their cud. Cows in some dairy
farms wander around and eat fresh grass (i.e. grazing).
In other farms, they are grain-fed, hay, or silage
(conserved forage) and remain all day in close quarters
known as confined animal feeding operations (CAFOs),
some of which house thousands of animals. Many large
dairy farms utilize growth hormones and antibiotics
during the rearing process to artificially increase a cow's
milk production and to decrease the spread of infectious
diseases among their cows.

3. In the Past: A cow is ready to be milked when her udder is full. The
farmer has some flexibility when making a schedule of cow milking
times. Usually, cows are milked in the early morning and again in
the late afternoon. It is possible to milk a cow by hand. However,
milking a whole herd of cows twice a day in this manner would take
a great deal of time and energy. Before the invention of milking
machines, people milked their dairy cows by hand by squeezing
gently on the cow's teats using the thumb and forefinger. Some
people continue to milk a little by hand today.
Today: Cows are normally milked at least twice a day. Milking time
takes about five minutes per cow depending on the type of machine
and the amount of milk the cow is producing. Most dairies have
enough machines to milk more than 20 cows at one time. Milking
machines mimic the action of a young calf by creating a pulsating
vacuum around the teat, which causes the milk to be released from
the udder.

4. Milk storage vats or silos are refrigerated and come in
various shapes and sizes. Milk is usually stored on the
farm at 39 degrees Fahrenheit, or colder, for no more
than 48 hours. Vats and silos are agitated to make sure
that the entire volume remains cold and that the milkfat
does not separate from the milk. After milk has been
collected, storage vats and stainless steel pipes are
thoroughly cleaned before the farmer milks again.

5. Milk is collected from the farm every 24 or 48 hours. The
tankers that are used have special stainless steel bodies
which are heavily insulated to keep the milk cold during
transportation to the processing factory. Milk tanker
drivers are accredited milk graders, qualified to evaluate
the milk prior to collection. Tanker drivers grade and if
necessary reject milk based on temperature, sight, and
smell. A representative sample is collected from each
farm pickup prior to being pumped onto the tanker. After
collection, milk is transported to factory sites and stored
in refrigerated silos before processing.

6. Samples of milk are taken from farm vats prior to
collection and from the bulk milk tanker upon arrival at
the factory. Samples from the bulk milk tanker are tested
for antibiotics and temperature before the milk enters the
factory processing area. Farm milk samples are tested
for milkfat, protein, bulk milk cell count and bacteria
count. If milk does not meet quality standards it is
rejected. Most farmers are paid on the quality and
composition of their milk.

7. Whole milk, once approved for use, is pumped into
storage silos where it undergoes pasteurization,
homogenization, separation and further processing.

8. •Pasteurization: Involves heating every particle of milk
to a specific temperature for a specified period of time
and cooling it again without allowing recontamination.
Homogenization: Involves pushing the raw milk through
an atomizer to form tiny particles so that the fat is
dispersed evenly throughout the milk, stopping the fat
from floating to the top of the container.

9. Separation: Involves spinning milk through a centrifuge
to separate the cream from the milk. After separation,
the cream and remaining milk are remixed to provide the
desired fat content for the different types of milk being
produced. For "whole milk," the cream is reintroduced
until the fat content reaches 3.25%. For "low fat milk,"
the fat content is 1%. For "skim milk" (sometimes called
nonfat milk) the fat content is .05%.
Further processing: Includes micro-filtration, increasing
the storage life by ultra high temperature (UHT)
treatment, and mixing or culturing milk for flavored and
yogurt products.

10. Now the milk is ready to be packaged for delivery to the
stores. The milk travels through pipes to the automatic
packaging machines that fills and seals the milk into
paper cartons or plastic jugs. As the containers move
through the assembly line, a date is printed on each of
them to show how long the milk will stay fresh.

11. After packaging, the milk is finally ready for the
customers, and it is stored in a big, refrigerated room
until it is delivered to stores to be sold.