cattle. In India people let cattle roam
freely throughout the cities and the
countryside. This is because followers of
Hinduism consider cattle to be holy.
Physical Features and Breeds
There are many different breeds of
cattle. Cattle of the same breed have a
similar color and size. Their coat of hair
may be black, white, gray, yellow,
brown, or red. Cattle may also have
spots or areas of different colors.
Depending on the breed, bulls weigh
from 1,000 to 4,000 pounds (450 to
1,800 kilograms). Cows weigh from 800
to 2,400 pounds (360 to 1,000 kilo-
Saint Colman’s Cathedral in Cobh, Ireland,
towers above the surrounding buildings.
Gauchos, or cowboys, herd cattle in the
Patagonia region of Argentina.
BRITANNICA STUDENT ENCYCLOPEDIA Cattle 61
grams). Many breeds have horns, but
some do not.
People raise some breeds mostly for their
milk and others mostly for their meat.
Cattle raised for milk are called dairy
cattle. The most popular dairy cattle in
the United States include the Holstein-
Friesian, Brown Swiss, Jersey, and
Guernsey breeds. Cattle raised for beef
include the Angus, Shorthorn (or
Durham), Hereford, and Brahman
breeds.
Many domestic breeds originally came
from Europe. Some originally came
from Asia. For example, Brahmans originally
came from India. Brahmans look
different from other domestic cattle.
They have a hump over their shoulders
and neck, curving horns, and drooping
ears.
Behavior
Wild and domestic cattle eat grasses and
other plants. After they swallow their
food, they bring it up from the stomach
to chew and swallow it again. This process
is called chewing the cud. It helps
cattle to digest tough plants. Farmers
may also give special feed to domestic
cattle to make them fatter.
Cattle and Humans
Cattle are very important to the economies
of many countries as well as to
small farmers. Cattle provide people
throughout the world with meat, milk,
cheese, and butter. People also make
cattle hides into leather goods. In addition,
cattle help to plow farmers’ fields
and haul heavy loads.
#More to explore
Bison • Buffalo • Mammal • Yak
Cave
A cave is a natural hollow space under
the ground that has an opening large
enough for a person to enter. Caves
range in size from tiny passages to huge
systems of connected “rooms” and tunnels.
The world’s longest cave system is
Mammoth Cave, in the U.S. state of
Kentucky. It is more than 350 miles
(560 kilometers) long. Large caves are
often called caverns.
Types of Caves
Most caves are called solution caves.
Solution caves most often form in places
where there is a type of rock called limestone.
Limestone is a soft rock that dissolves,
or breaks down, easily in water.
Cattle tear
grass out of
the ground
with a sideways
movement
because
they have no
upper front
teeth.
Huge stalagmites are a highlight
of Carlsbad Caverns in New
Mexico.
62 Cave BRITANNICA STUDENT ENCYCLOPEDIA
As water flows through small cracks in
the limestone, the limestone dissolves
and the cracks get bigger. Over a long
time these cracks become large enough
for people to enter.
Not all caves form in limestone. They
can form in such rock as gypsum,
marble, and dolomite. Caves may also
form when melted rock, called lava,
flows from volcanoes. The lava on the
surface may cool while the lava beneath
flows away. When this happens a cave is
sometimes created. Caves may also form
when earthquakes cause large cracks in
solid rock. Ocean waves sometimes form
sea caves along the coast. The action of
the waves removes soft rock and forms
hollow spaces.
Some caves do not form in rock. Glaciers,
or huge areas of ice that move over
land, can form ice caves. As water melts
on the glacier’s surface, it flows into
cracks in the ice. The water then carves
out caves beneath the surface of the ice.
Cave Features
After a solution cave is formed, water
continues to drip into it. Minerals in the
water are slowly deposited on the ceiling
and floor of the cave. Over time those
mineral deposits, or crystals, build up
into large formations. Those that hang
down from the ceiling are called stalactites.
They look like icicles. Stalagmites
point up from the floor. They usually
grow under dripping stalactites. Sometimes
stalactites and stalagmites join
together to form columns.
Cave Exploration
Cave explorers are people who like to
find and explore caves. They are also
called cavers or spelunkers. Sometimes
they wiggle through tiny passages just
big enough to get through. Other times
they walk through passages that are tall
Water dripping into a cave contains minerals that build up on the ceiling and the floor.
Over time the minerals may form stalactites, stalagmites, and columns.
BRITANNICA STUDENT ENCYCLOPEDIA Cave 63
and wide. Sometimes they need ropes
and special gear to cross or go down
deep holes.
Cave exploration can be dangerous.
Cavers are well trained to know how to
explore safely. A person should never
enter a cave without experienced cavers.
Cave-dwelling Animals
Caves are the home of many different
animals. Some, such as bats, live in caves
but come out at night to feed. Other
cave-dwelling animals live their entire
