Domestic cow

Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Genus and Species: Bos taurus taurus
  • Brown cow with white head and chest standing in a muddy field
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Domestic cow

Cattle are important domesticated animals that provide meat and milk. Many breeds exist, some emphasizing beef production, some emphasizing dairy production. The Smithsonian's National Zoo exhibits a polled Hereford, which is a beef breed.

Physical Description

Domesticated cattle belong to the genus Bos and the two species taurus and indicus. All breeds of British and European cattle such as Angus, Hereford, Holstein, Shorthorn and Simmental belong to the taurus species. The humped cattle of the tropical countries, such as Brahman and Africander, belong to the indicus species, also called Zebu or "eared" breeds.

In most species, the bull is much larger than the cow. Breeds can be either polled (genetically hornless) or horned. Both male and female wild cattle species have horns, with the bull's horns larger and thicker than the cow's.

Cattle have panoramic vision, which means they can see almost all the way around themselves without moving their heads. Their depth perception, however, is only focused in a small forward view. This means that, while a cow might be able to see you standing at its side, it cannot necessarily judge how close or far away you actually are. This might explain why a cow can be startled when you approach even though you have been in its field of vision for some time.

Beef cattle have been bred and selected primarily for the production of meat and many breeds have been developed or adapted for special conditions. There are over 60 breeds of beef cattle in North America. Major registered breeds, listed in order of numbers, are Angus, Hereford, polled Hereford, Charolais, shorthorn, Brahman, Brangus and red Angus. The various breeds of beef cattle also differ in mature size, growth rate, gestation length and birth weight. Beef cattle differ physically from dairy cattle; they have a broader, heavier set body, with a shorter neck and legs than dairy cattle. There is no "best" type or breed for beef production because of extensive variations in climates, production conditions and market requirements.

The Zoo exhibits the polled Hereford breed of beef cattle. Warren Gammon developed the polled Hereford breed in Iowa in 1898. Polled Herefords were developed from the horned Hereford breed, which was founded in the mid-18th century by the farmers of Hereford County, England. Among the horned Herefords, an occasional calf would be born that did not develop horns. These cattle soon came to be called "polled," which means naturally hornless. In 1901, Gammon established the polled Hereford breed registry and today the registry is combined with the American Hereford Association. Polled Herefords are generally docile.

Polled Herefords are medium-sized cattle with a red body color. The head and front of the neck, the brisket, underside and switch are white. They have well developed forequarters, a deep brisket, broad head and stocky legs.

Dairy cattle are those breeds that have been developed primarily to produce milk. In North America, the major breeds of dairy cattle are the Holstein-Friesian, Guernsey, Jersey, Ayrshire, brown Swiss, and milking shorthorn. The Holstein-Friesian is the largest breed and produces the largest volume of milk. The Brown Swiss, Ayrshire, Guernsey and Jersey follow Holsteins in size. Breeds also differ in color; volume of milk produced, and milk composition.

In 2008, the average dairy cow in the U.S. produced about 20,461 pounds of milk. Individual cows may produce several times this average amount. Milk is recorded as pounds instead of gallons because dairy producers are paid by the weight of the milk. Dairy cows normally give milk for five or six years, but some continue to give milk at the age of 20 or older. (Dairy cows only develop an udder and produce milk after becoming pregnant. A dairy cow that never is pregnant will not produce milk.

The origin of Holstein cows can be traced back over 2,000 years to the north region of Friesland in Holland. It is believed that migrating herds of black cows and herds of white cows intermixed and the breed was born. When first imported to the United States in 1852, they were called Dutch cows. The reason for including the name "Holstein" is uncertain. Nine out of ten dairy producers milk Holsteins.


Polled Herefords, a breed of beef cattle, are medium-sized cattle. Mature males may weigh up to 1,800 pounds (817 kilograms), while mature females may weigh around 1,200 pounds (545 kilograms). The average height of bulls is 4.5 feet (1.37 meters) at the hip, with cows reaching about 4.25 feet (1.30 meters). 

Native Habitat

Modern domestic cattle evolved from a single, early ancestor, the auroch. It is believed the last surviving auroch was killed in 1627 in Poland. Early cattle served a triple purpose. They provided meat, milk and labor to their owners. In many cultures, cattle have spiritual, economic or political importance far beyond the monetary value of the animals themselves

Food/Eating Habits

Cattle are ruminants, eating hay, corn, soybeans, grass, wheat and silage (fermented feed). The ruminant's complex, four-compartment stomach enables it to digest and convert these types of plant material into energy and important "building blocks" of the body. Cattle can make use of low quality, or non-productive rangeland, but must be properly managed to avoid causing damage to the environment.

Cattle are herbivores. A typical cow or calf's diet consists of hay or roughage (80 to 90 percent of total dry matter), some type of commercial feed that includes grain, vitamins and minerals, and water. Proper feeding of cattle can be complicated and requires a combination of scientific knowledge, creativity and good management skills. The amounts and types of feed that a single cow, calf or bull is fed depends on how much he/she weighs, how old he/she is, how much milk she gives (for cows), and where she is in her gestation cycle. Cattle spend approximately 6 hours a day grazing and another 8 hours ruminating.The Zoo's Hereford heifer receives mixed grass hay twice daily. She is also given leafeater biscuits for enrichment and training purposes.

Social Structure

Domestic cattle are social animals and live in groups called herds.

Reproduction and Development

Females reach sexual maturity at approximately one year, having their first calf around two years of age. Breeding can continue to around 12 years and can occur year round. Estrus (heat) is the period of time when a cow or heifer is sexually receptive and signals that an egg is about to be released. It normally occurs every 18 to 24 days. The average time a female is in standing heat is about 12 to 18 hours. A female in standing heat allows others to mount her as she stands. Ovulation follows standing heat. Breeding can be natural or through artificial insemination.

Usually one calf is born after nine months of gestation. Labor usually lasts two to four hours, with the calf presented front feet first with the head tucked between the legs. Occasionally a cow may have twins. If the twins consist of a male (bull) and female (heifer), the heifer calf is usually infertile (called a freemartin heifer). Infertility in freemartin heifers occurs due to a transfer of hormones or cells from the developing male calf, causing the female's reproductive tract to be underdeveloped.

Calves are born well developed, able to stand and walk within an hour after birth. When the calf is first born, it needs to drink milk within the first few hours. This special milk is called colostrum and has antibodies that help the calf fight off disease and stay healthy. Cows produce colostrum for the first 72 hours after calving. Calves are weaned at about 6 to 7 months old.

Kids’ Farm is home to one Hereford cow named Rose. Rose is red and white with a long curly coat in the winter and a short sleek coat in the summer. Rose is a beef breed.