A pig has a snout for a nose, small eyes, and a small tail,
which may be curly, kinked, or straight. It has a thick body and
short legs. There are four toes on each foot, with the two large
middle toes used for walking.
Pigs are omnivores, which means that they consume both plants and small animals. Pigs will scavenge and have been known to eat any kind of food, including dead insects, worms, tree bark, rotting carcasses, excreta (including their own), garbage, and other pigs. In the wild, they are foraging animals, primarily eating leaves and grasses, roots, fruits and flowers. Occasionally, in captivity, pigs may eat their own young, often if they become severely stressed.
A typical pig has a large head with a long snout which is strengthened by a special bone called the prenasal bone and by a disk of cartilage in the tip. The snout is used to dig into the soil to find food and is a very sensitive sense organ. Pigs have a full set of 44 teeth. The canine teeth, called tusks, grow continually and are sharpened by the lowers and uppers rubbing against each other.
Pigs that are allowed to forage may be watched by swineherds. Because of their foraging abilities and excellent sense of smell, they are used to find truffles in many European countries. Domesticated pigs are commonly raised as livestock by farmers for meat (called pork), as well as for leather. Their bristly hairs are also used for brushes. Some breeds of pigs, such as the Asian pot-bellied pig, are kept as pets.
A female pig can become pregnant at around 8-18 months of age. She will then go into heat every 21 days. Male pigs become sexually active at 8-10 months of age. A litter of piglets typically contains between 6 and 12 piglets.
Pigs do not have functional sweat glands, so pigs cool themselves using water or mud during hot weather. They also use mud as a form of sunscreen to protect their skin from sunburn. Mud also provides protection against flies and parasites.
Domestic pigs that have escaped from farms or were allowed to forage in the wild, and in some cases wild boars which were introduced as prey for hunting, have given rise to large populations of feral pigs in North and South America, Australia, New Zealand, Hawaii and other areas where pigs are not native. Accidental or deliberate releases of pigs into countries or environments where they are an alien species have caused extensive environmental change. Their omnivorous diet, aggressive behaviour and their feeding method of rooting in the ground all combine to severely alter ecosystems unused to pigs. Pigs will even eat small animals and destroy nests of ground nesting birds. The Invasive Species Specialist Group lists feral pigs on the list of the world's 100 worst invasive species and says about them:
“ Feral pigs like other introduced mammals are major drivers of extinction and ecosystem change. They have been introduced into many parts of the world, and will damage crops and home gardens as well as potentially spreading disease. They uproot large areas of land, eliminating native vegetation and spreading weeds. This results in habitat alteration, a change in plant succession and composition and a decrease in native fauna dependent on the original habitat. ”
Pigs harbor a unique (when compared to other domestic animals)
range of parasites and diseases that can be easily transmitted
to humans. These include trichinosis, cysticercosis, and
brucellosis. Very commonly, pigs are also known to host large
concentrations of parasitic ascarid worms in their digestive
tract. The presence of these diseases and parasites is one of
the main reasons why pork meat should always be well cooked or
cured before eating. Some religious groups that consider pork
unclean refer to these issues as support for their views.
Pigs are extremely susceptible to pneumonia, usually caused by weather. Pigs have small lungs in relation to body size; for this reason, bronchitis or pneumonia can kill a pig quickly.
Pigs can be aggressive and pig-induced injuries are relatively common in areas where pigs are reared or where they form part of the wild or feral fauna.
Domestic pigs are often inbred, leading to the expression of recessive traits. Congenital malformations are common. One such malformation is the duplication of a pig's head.
This Pig Page is Copyright The Animal Web Guide © 2004 - 2009 Chuck Ayoub