DESPITE being almost without government subsidy, the swine industry is the second leading contributor to Philippine agriculture -- after rice.

The strong growth in demand for pork has the potential to increase income opportunities and alleviate poverty among rural and agricultural households in the Philippines, where rural poverty remains high.

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Pig production is the largest contributor to meat output in the country. As of January 1, 2008, the country's swine total inventory was estimated at 13.7 million head, up by 1.80 percent compared to the previous year’s level.

About 71 percent of swines are raised in backyard farms while 29 percent are in commercial farms. "In almost every rural household in the Philippines, hog-raising is a very popular enterprise," said Roy C. Alimoane, director of Davao-based Mindanao Baptist Rural Life Center (MBRLC) Foundation Inc.

After all, no other backyard animal has the same versatility as the swine.

Swine is not only a good source of high quality red meat but it is also an important source of essential and useful by-products derived from every part of the animal.

In the past, a farm family almost always invested their wealth in a pig.

After all, out from pigs you can get pork, bacon, and sausage. They also act as refuse bin, eating all the scraps and family’s leftovers.

When asked if the head of the family had any money, he would reply: "No. All my money is in the pig."

When people stopped raising pigs, they made a replica where they could "put their money in." In time, the practice of saving money in a pig came into existence and it got called the "piggy bank."

Swine is not only for eating and a possible solution to financial woes. In fact, pigs are very important in medicine. Their heart valves, especially treated and preserved, can be surgically implanted into humans to replace heart valves weakened by disease and injury.

Pig pancreas glands are an important source of insulin hormone used in the treatment of diabetes.

Despite its economic importance, the pig industry has its shares of problems.

Last year, the Bureau of Animal Industry (BAI), a line agency of the Department of Agriculture (DA), spearheaded the depopulation of 6,000 hogs in a Bulacan farm to prevent the spread of Ebola Reston virus.

It also placed under surveillance thousands of backyard swine farms across Luzon as part of long-term measures to rid the country of the infection.

Last April, another big blow came when a never-before-seen strain of swine flu went deadly, killing infected people in Mexico and the United States.

Immediately, the National Federation of Hog Farmers Inc. issued a formal statement assuring the public that local pork is safe from swine flu and they can continue to eat pork.

After all, swine flu viruses are not transmitted by food. "There is scientific evidence to show that when you cook pork well, all viruses present in it will be killed," the federation said in a statement.

"Eating properly handled and cooked pork or pork product is safe," assures the US Centers for Disease Control and Prevention (CDC) based in Atlanta, Georgia. "Cooking pork to an internal temperature of 160 degrees F kills all viruses and other food-borne pathogens."

As a precautionary measure, the government banned the import of hogs and all other pork products from the US, which accounted for 27 percent of the 109.36 million kilograms of pork products imported last year.

Mexico, however, is not a major source of pork products for the country.

Besides the temporary ban, Agriculture Secretary Arthur Yap ordered the BAI to make easily available to farmers vaccines against swine flu.

"I have ordered that the restriction on the use of swine influenza vaccine be lifted and I encourage hog farmers to regularly vaccinate their pigs against swine influenza as the vaccine will be readily available," he said.

Swine flu (shorter term for influenza) is a highly contagious acute respiratory disease of pigs. It is caused by a virus, a pack of protein and DNA that lacks the capacity to self-reproduce. So it infects a cell, hijacks the inner machinery, and uses it to reproduce. The virus reproduces until there are so many copies that the cell bursts and the virus spills out, spreading to other healthy cells.

"The (swine flu) virus may live indefinitely in the respiratory tract, but the virus does not persist in the body, and the disease is caused only by their combined action," informs the book, A Reference Unit to Hog Production.

"However, the lung worm harbors the virus and transmits to its egg, which is passed from the hog through the manure. Then earthworms eating this manure ingest the lungworm eggs containing the virus, and these eggs hatch inside the earthworm with the lungworm larvae remaining there. When a hog roots up the earthworm and eats it, the hog is then infected with the virus. This provides the opportunity for the disease to recur."

Among pigs, swine flu is characterized by the sudden prostration of a large part of the herd. The first symptoms noticed are usually loss of appetite and a rapid jerky type of breathing accompanied by high fever. When the pigs are aroused from their beds, they are listless and often have violent coughing spells, sometimes vomiting stringy mucus. The eyes may be red, swollen, and watery and there may be a discharge from the nose.

"The disease usually runs its course in about one week," the book states. "The death rate is very low and infected animals that survive for 4-5 days usually make a complete recovery in a few days. The mortality rate from swine flu is usually 2-5 percent."

Flu viruses are classified as A, B, or C. The A viruses, which infect ducks, chickens, pigs, and whales, as well as humans, are the most dangerous. They are divided into groups based on two proteins -- haemagglutinin (HA) and neuraminidase (NA), which spike out from their surfaces.

Scientists have identified 16 subtypes of HA and nine of NA. This means there are 144 possible combinations of A viruses.

Swine flu viruses, which are touted to be "the trickiest known to medical science," are most commonly of the H1N1 subtype, but other subtypes are also circulating in pigs (example: H1N2, H3N1, H3N2).

Pigs can also be infected with avian influenza viruses and human seasonal influenza viruses as well as swine influenza viruses. The H3N2 swine virus was thought to have been originally introduced into pigs by humans.

"The virus is spread among pigs by aerosols, direct and indirect contact, and asymptomatic carrier pigs," explains the Geneva-based World Health Organization (WHO). "Many countries routinely vaccinate swine populations against swine influenza."

Swine flu viruses do not normally infect humans. However, sporadic human infections with swine flu have occurred. Most commonly, these cases occur in persons with direct exposure to pigs (e.g. children near pigs at a fair or workers in the swine industry). In addition, there have been documented cases of one person spreading swine flu to others.

Dr. Eric Tayag, chief of the National Epidemiology Center of the Department of Health, said the swine flu virus is spread via aerial droplets and could be passed from pig to human or human to human.

People may also become infected by touching something with flu viruses on it and then touching their mouth or nose.

The infectious disease specialist said infected individuals could exhibit symptoms of the illness three to five days after being infected. The symptoms of swine flu in people, according to the CDC, are similar to the symptoms of regular human flu and include fever, lethargy, lack of appetite and coughing. Some people with swine flu also have reported runny nose, sore throat, nausea, vomiting and diarrhea.

The CDC points out that swine flu in humans is most contagious during the first five days of the illness although some people, most commonly children, can remain contagious for up to 10 days.

An advisory from the health department said people should cover their nose and mouth with tissue when coughing or sneezing, wash their hands regularly with soap and water, especially after coughing or sneezing, and avoid close contact with sick people or crowded places.

Flu viruses can live on surfaces for several hours, like a doorknob just touched by someone who sneezed into his hand.

A sick or feverish person should be closely monitored and stay at home to limit contact with others. When the fever and flu persists, doctors should be consulted immediately. “Refrain first from kissing or shaking hands with one another,” urged Dr. Tayag.

The WHO referred to the current swine flu epidemic as a "public-health emergency of international concern."

Its director-general, Dr. Margaret Chan, however, admitted the outbreak “has pandemic potential” because it is apparently being transmitted from human to human. But she added it is far too early to predict whether a pandemic will occur.