The Asian Pig Veterinary Society (APVS) meeting was recently held in Thailand. Unfortunately, it was scheduled at exactly the same time as the AASV meeting – which precluded us from attending both meetings. In this message, I will write about what was on the minds of our colleagues half a world away during the first week of March. The conference did occur before the natural disaster in Japan. I am certain that today, the hearts and minds of those in Asia, and the rest of the world, are focused on concern for the Japanese people.
The first general session of the APVS was dedicated to pig production statistics and the disease concerns and control programs from each Asian country represented at the conference. Pork is the meat of choice in Asian countries. People in the Philippines and Vietnam consume 14.7 and 21 kg of pork per person per year, respectively. Production in Japan and the Philippines cannot supply the demand for pork, but their industries wish to build to the point where the need for imports is eliminated. Japan and Korea each have approximately 7000 farms, whereas Thailand has 15,000. The numbers of farms in these countries are decreasing as herd size increases. However, much of the pig production in the Asian countries occurs on smallholder or backyard farms. By country, the proportion of farms using this traditional method of pig rearing represents 71% (Philippines), 85% (China), 80% (Vietnam), and 80% (Thailand) of farms, respectively. These smallholder farms have fewer than 10 sows or 50 growing pigs. In Thailand, 80% of farms produce 24% of the pigs, while 1% of the farms have at least 5000 pigs and produce 34% of the pigs. Pig production in China represents 41% of the world’s pork production. Vietnam has had an annual increase in pig inventory of 5% per year since 2007. There is concern that some of the local, more disease-resistant breeds in Vietnam are being replaced by improved breeds that are not as robust when raised under local conditions.
There are several major concerns with respect to disease control and biosecurity. The smallholder farmers typically cannot access veterinary assistance and cannot afford disease-control programs such as vaccination. In the Philippines, the government subsidizes porcine reproductive and respiratory syndrome (PRRS) vaccination on these farms. In China, there is mandatory and subsidized vaccination against PRRS, foot-and-mouth disease (FMD), and pseudorabies. The modified-live PRRS vaccine used in China is produced and distributed by the government. Pigs move between farms and from farm to farm through the markets or a middle man. Dr Hien Le is a PhD student at the University of Guelph working with Dr Zvonimir Poljak and myself. His work in Vietnam found that factors associated with clinical signs due to highly pathogenic PRRS virus included purchasing pigs from the local market, keeping sows, and raising ducks on the farm. Among the Asian countries, spread of highly pathogenic PRRS was tracked by time and geographical spread. Incursion of the disease into each country was explained by movement of pigs across the borders. Loss of production due to this highly pathogenic strain of PRRS was extensive.
Although the Philippines is free of FMD, most countries continue to struggle with the problem due to either endemic problems or outbreaks between 2006 and 2011. Japan stopped vaccinating in February 2011, continues extensive testing, and hopes soon to be free of FMD. Their pseudorabies eradication program also appears to be succeeding. In February 2011, FMD killed the majority of suckling pigs in Korea. Since then, Vietnam began vaccinating sows twice a year and China has compulsory vaccination. Thailand has ongoing surveillance for FMD. Classical swine fever (CSF) also continues to plague many of these countries. Korea has an eradication plan for CSF and pseudorabies. Vietnam considers CSF endemic.
Streptococcus suis was mentioned as a significant public-health problem in China and Vietnam. Many farmers butcher their own pigs and the spread of S suis from pigs to people is a concern. Co-infection of porcine circovirus type 2 (PCV2) and PRRS with bacterial infections such as S suis and Hemophilus parasuis was mentioned by the speakers from China, Vietnam, and Korea. Co-infection of piglets with agents causing diarrhea, such as porcine endemic diarrhea, Escherichia coli, rotavirus, transmissible gastroenteritis, and coccidiosis, appears to be a concern in many countries.
As with any conference, the hallway discussions were particularly interesting. Veterinarians highlighted the lack of money for smallholder producers to vaccinate or treat their pigs, the movement of sick pigs, and the lack of diagnostic capabilities. One veterinarian from the Philippines asked about the relationship between the enzyme-linked immunosorbent assay and the polymerase chain reaction (PCR) test results when used to understand control of PCV2 in a finisher-pig herd. In her country, she has no access to PCR tests. She told me that Actinobacillus pleuropneumoniae was a significant problem in the herds, and that herds free of both Mycoplasma hyopneumoniae and PRRS were non-existent. She described the difficulty of disseminating information to the smallholder farmers in her country of 710 islands. It left me wanting to visit this country that dots the South Pacific.
The people at the APVS were friendly and welcoming. The APVS banquet ended with everyone showing hope and solidarity by all singing “We are the World.” In Asia, pork is a highly valued meat, veterinarians and farmers struggle with many more pig diseases than we do in North America, and it is difficult to spread veterinary assistance and knowledge to thousands of smallholder pig farmers. The next opportunities to meet with our Asian colleagues will be at the International Pig Veterinary Society Congress in Korea (2012) and at the APVS meeting in Vietnam (2013).
-- Cate Dewey, DVM, MSc, PhD