There are three types of domestic goats—those used for dairy, meat and fiber—and more than 200 recognized domestic breeds.
Some goats are polled, or genetically hornless. Others may have scimitar- or corkscrew-type horns, but many are dehorned at an early age to prevent injury to other goats and handlers. Certain breeds have straight noses, while others have convex or slightly dished noses. Their ears may be erect or drooping and vary in size.
Their short or long hair can be curled, silky or coarse. They may also have beards and wattles on their necks. Goats come in many colors: solid black, white, red, brown, spotted, two- and three-colored or blended shades. They may also have facial stripes or black-and-white saddles.
Goats’ eyes have rectangular pupils. Eye color varies, but yellow and brown are the most common. Goats will often browse at night, and it is believed that they have excellent night vision.
The Zoo exhibits two different goat breeds: Nigerian dwarves and San Clemente Island goats. Nigerian dwarves were first registered by the International Dairy Goat Registry in 1981. They are the only true miniature goat breed of the dairy type and have features similar to those of other dairy goat breeds, only smaller. Their face is straight or slightly dished, and their ears are upright and alert. They have straight, short-to-medium length hair and come in many colors, the most common being black, brown and gold. White markings, spots and other color combinations are also common.
San Clemente Island goats developed naturally when domestic goats were allowed to run feral on San Clemente Island, located 68 miles (110 kilometers) west of San Diego, California. Though the exact genealogy of San Clemente Island goats is a puzzle, researchers believe they were brought to the island from neighboring Santa Catalina Island in 187,5 and it was from these Spanish goats that the San Clemente Island goat developed.
In 1934 the U.S. Navy took ownership of San Clemente Island, and a 1972 census found that 15,000-18,000 goats were living on the 57 square mile (91.7 square kilometer) island. These feral goats were causing devastation to the island’s natural ecosystem.
In order to restore the natural habitat, the Navy began goat-eradication programs that would continue until April 1991 when the island was completely goat free. During this time, some 6,000 live animals were returned to the mainland to be re-domesticated. However, many of the males were neutered, so only a small breeding population survived. San Clemente Island goats are one of the rarest domestic animal breeds in the world. There are estimated to be only about 250 San Clemente Island goats worldwide, and they are designated as critically endangered by the American Livestock Breeds Conservancy.
The San Clemente Island goat is a small breed, with males, or bucks, averaging a height of 23.6 inches (60 centimeters) and females, or does, a height of 22.4 inches (56.8 centimeters). This small size is likely the result of insular dwarfism from adapting to island life. These goats have a tan to dark-red coat with black markings. They are lean and have graceful movements that are considered “deer-like.” Both males and females have horns, and it is not uncommon for females to exhibit supernumerary, or extra, teats on their udders.
The goat is one of the smallest domesticated ruminants. Goats vary from as little as 20 pounds (9.1 kg) in weight and 18 inches (45.7 cm) tall in the mature female dwarf goat, to 250 pounds (113.5 kg) and 42 inches (106.7 cm) in height for Indian Jamnapari, Swiss Saanen, and Alpine.
Domestic goats are members of the Bovidae family, which includes gazelles, African antelope, bison and other domesticated species, such as sheep and cattle. Goats, along with sheep, were among the earliest domesticated animals. Goat remains have been found at sites in western Asia dated around 7,000 B.C.
Domestic goats are primarily descended from the Bezoar goat, Capra aegagrus, except for the Angora, Cashmere and Damascus breeds, which descended from the Markhor, Capra falconeri.
Like other ruminants, goats have a four-compartment stomach. Their digestive system works nonstop throughout their adult life. While some animals have digestive organs and secretions that alternate between periods of stress and inactivity, goats must continually produce digestive juices and enzymes 24 hours a day.
A goat’s intestinal canal is about 100 feet (30.5 meters) long, which allows better nutrient absorption from grass and other roughage. It takes 11 to 15 hours for feed to pass through a goat’s digestive system.
A goat’s lips, teeth and tongue are its primary grazing tools. Its lips help it selectively grab feed. Because a goat’s upper jaw is wider than its lower jaw, it can only use one side of its mouth at a time to grind food. This causes an accentuated sideways movement of the jaws while chewing, which in turn sharpens the molars into a point on the inner edge of the lower teeth and the outer edge of the upper teeth.
Goats require more nutrients than larger ruminants and are good browsers, feeding on a variety of shrubs, woody plants, weeds and briars. Unlike sheep and cattle, goats can also survive on bushes, trees, desert scrub and aromatic herbs.
In a pasture situation, goats are “top-down” grazers. They begin by eating seed heads or the tops of plants, then progressively forage down, which results in uniform grazing. They do not like to graze close to the ground. Grazing goats have also been observed selecting grass over clover, preferring browsing to grazing, grazing along fence lines before the center of a pasture, and refusing to graze forage that has been trampled and soiled.
At the Smithsonian’s National Zoo, goats eat mixed grass and herbivore feed.
Many goats are seasonal breeders, influenced by the length of daylight. Goats typically reach sexual maturity at 6 months of age.
In temperate zones, females begin to cycle in the late summer and show signs of heat (estrus) for one to two days about every 21 days, through January. The strongest heat cycles occur from November to January.
Nearer the equator, goats come into heat throughout the year. In these areas, it is possible for a goat to have more than one litter per year, because the length of pregnancy is just five months.
Female goats weight between 3 and 9 pounds (1.36 to 4.1 kilograms) at birth. Twins will typically be 1 pound lighter and males 0.5 pounds (0.23 kilograms) heavier. It is not unusual for a goat to give birth to twins. There is also a high percentage of triplets.
Kids’ Farm exhibits two Nigerian dwarf goats and two San Clemente Island goats.
The Nigerian dwarf goats, sisters Fiesta and Fedora, were born on April 10, 2015. Fiesta is white with black spots, and Fedora is brown and black.
The Zoo’s San Clemente Island siblings, male Mortimer and female Marla, were born on May 30, 2008.