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Swine Health and Production — News November/December 1997

   

News

November and December, 1997

American Board of Veterinary Practitioners 1998 Application Deadline and Examination Dates

The American Board of Veterinary Practitioners (ABVP) is accepting applications for 1997 examinations. Applications require:

Applications are due in the ABVP office at 5:00 p.m., March 1, 1998. All practice category examinations will be administered in Chicago at the Marriott O’Hare, December 11-13, 1998 for those who qualify. Practice categories now available include:

Application booklets may be secured by contacting:

ABVP
530 Church Street
Suite 700
Nashville TN 37219

phone: 615-254-3687
fax: 615-254-7047
email: abvp@wmgt.org

Checkoff dollars at work for producers and veterinarians

The national pork checkoff program is a producer "self-help" system that has enabled the United States pork industry to secure name brand recognition through the marketing slogan "Pork. The Other White Meat(R)." Growth in pork exports alone in the last 10 years have contributed $2.36 more value per market hog and made the United states a net exporter of pork.

The legislative checkoff program collects funds on all market hogs, feeder pigs and breeding stock produced in the United States as well as imported hogs and pork products.

The National Pork Board–established under the Pork Promotion, Research and Consumer Information Act of 1985–develops plans and budgets, and awards contracts to carry out coordinated programs designed to strengthen the position of pork in the marketplace. The Pork Board oversees $58 million of national checkoff programs.

Access to global markets and maintenance of consumer demand depends on the safety of pork products and the health status of United States herds. The pork industry is allocating more than $2.8 million in 1997 on swine health and pork safety efforts. Next year, the efforts for swine health, meat quality, and food safety will be expanded to nearly $4.5 million.

More than $400,000 is being invested into porcine reproductive and respiratory syndrome (PRRS) research projects this year to better understand its transmission, pathogenesis, epidemiology, and control measures. The Pork Quality AssuranceSM (PQA) Program, another highly successful checkoff-funded program, is an essential marketing tool for quality United States pork around the world.

Beginning this year, a production research program on the maternal sow line will evaluate the sow’s contribution to pork production. It will track reproductive traits of sow longevity, litter size, and milking ability. The program will provide the pork industry with unbiased information that will assist producers in finding combinations of breeds and lines to design hogs for future markets.

Checkoff-funded research projects are underway and cover such key areas as odor, manure management, meat science, pork quality, nutrition, and genetics.

The National Pork Producers Council (NPPC), in cooperation with state producer associations, uses checkoff funds to provide information on timely industry topics through workshops, conferences, satellite broadcasts, and videotapes. For the second year, the NPPC is sponsoring the Swine Health Summit November 12-13. The Swine Health Summit provides producers access to information on key disease and production issues that affect herd efficiency and profitability.

The checkoff program is popular among producers. Ninety-one percent of pork producers surveyed believe the pork checkoff is benefiting the industry, according to a telephone survey. In addition, nearly eight out of 10 producers polled said that the checkoff program–and in particular consumer advertising, export development, and production research–has benefitted them personally. To make these types of programs possible, producers have agreed to assess their sales of market hogs, feeder pigs, and seedstock at the rate of 45¢ per $100 of sales.

Farm-to-farm sales of feeder pigs and seedstock are the most difficult types of sales to monitor for checkoff compliance. Producers or agents for producers sometimes do not understand their responsibilities to remit checkoff.

The United States pork industry has witnessed a resurgence in pork production in recent years through the formation of producer networks. These win-win alliances have, in some cases, involved feed companies and veterinary clinics.

As you assist your pork producer clients with health and management programs, the National Pork Board encourages your help in reminding producers involved in direct farm-to-farm sales of their checkoff responsibilities. Depending on your involvement in producer relationships of marketing or sales, you may also have a responsibility to collect and remit checkoff. For more information and details on the responsibility to collect and remit checkoff, please call the National Pork Board at 1-800-456-7675. Together, pork producers can make pork the Meat of Choice(TM).

Researchers discover first animal strain of hepatitis E virus

Scientists at the National Institute of Allergy and Infectious Diseases (NIAID) in Bethesda, Maryland, have identified a strain of hepatitis E virus in pigs that is very similar to the strain that causes disease in humans. However, there is no evidence that the pig virus causes disease in either humans or pigs. The finding, published in the September 2, 1997 issue of the Proceedings of the National Academy of Sciences, should help advance studies of hepatitis E disease in humans and eventually could lead to the development of a vaccine. "This is a very interesting finding that will open new avenues of research, and contribute to strategies to treat or prevent hepatitis E disease," says Robert H. Purcell, MD, chief of the hepatitis viruses section in NIAID’s Laboratory of Infectious Diseases (LID) and senior author of the study. "Unlike hepatitis A, B, and C, hepatitis E disease almost never occurs in the United States. However, epidemics of the disease do occur periodically in developing nations in Africa and Asia."

Hepatitis E virus is most commonly transmitted to people through contaminated drinking water in areas with poor sanitation. The disease generally affects young adults and usually is not life-threatening, except in pregnant women infected with the virus, for whom fatality rates of 15%-20% have been reported. According to the Centers for Disease Control and Prevention (CDC), virtually all cases of acute hepatitis E in the United States have occurred among travelers returning from areas where hepatitis E disease is endemic. Nevertheless, recent studies have shown that nearly 20% of healthy people in this country–even those who have not traveled abroad–have antibodies to hepatitis E virus or related agents in their blood. Similar evidence of exposure to hepatitis E virus or related agents also has been documented in primates and swine.

To explore the nature of these infections in pigs, Xiang-Jin Meng, MD, PhD, working with Dr. Purcell and their LID colleague Suzanne U. Emerson, PhD, screened swine blood samples with an assay designed to detect antibodies to strains of human hepatitis E virus. Most of the samples, taken from swine herds in the midwestern United States, tested positive for hepatitis E virus antibodies. In a separate analysis, piglets born to antibody-negative sows were found to seroconvert (develop antibodies to hepatitis E virus) when raised in large pens with other piglets. None of the piglets, however, showed any clinical signs of disease after seroconversion.

Using polymerase chain reaction (PCR) techniques, the LID scientists isolated putative hepatitis E virus genetic material from swine blood samples and compared its genetic sequence to that of human hepatitis E virus. They found that the swine virus was closely related to, but distinct from, human strains of the virus. "At the amino acid level, the swine and human strains are about 90% alike," explains Dr. Meng. "Among most human strains of hepatitis E virus, amino acid identity is between 97% and 99%." The researchers say their findings strongly suggest that a previously unrecognized strain of hepatitis E virus circulates in the swine population. "It’s important to remember that the virus strain isolated from the swine in this study is distinct from the strains known to cause disease in humans," explains Dr. Meng. "Still, further studies are needed to determine whether swine hepatitis E virus is species-specific or is circulating in the human population without causing disease. These subclinical infections of humans with swine hepatitis E virus might explain the relatively high prevalence of hepatitis E antibodies in healthy individuals in the United States." If that were the case, says Dr. Meng, the strong immunologic cross-reactivity of the swine and human strains suggests that swine hepatitis E virus could prove useful as a vaccine against the human virus.

The similarities between the swine and human viruses also suggest that pigs might provide an alternative animal model for studying hepatitis E virus infection. Currently, scientists must use expensive primate models to study the virus. "The possibility that swine hepatitis E virus may infect humans also raises a public health concern regarding the use of pig organs in human transplantation," cautions Dr. Purcell. "Nonpathogenic pig viruses could possibly become pathogenic in human transplant recipients, particularly since transplant patients receive immune- suppressing drugs." Apart from these concerns, Dr. Purcell adds, there is no evidence that the pig virus poses any threat to healthy humans or pigs. "Swine hepatitis E virus is probably common throughout the world," he says. "Antibodies to hepatitis E or related agents have been found in healthy swine as well as in several other species of domesticated and wild animals in a number of countries. Similarly, such antibodies have been found in most human populations, even where hepatitis E disease does not occur. Furthermore, the degree of genetic divergence of the swine virus from human hepatitis E virus suggests that it has been around for a long time."

In addition to the NIAID scientists, collaborators on this study include Patrick G. Halbur, DVM, PhD, of the Iowa State University College of Veterinary Medicine; Dale M. Webb, DVM, PhD, of the Illinois Department of Agriculture; James R. Lehman, DVM, of Atlanta, Illinois; and other veterinarians in Iowa and Illinois. NIAID, a component of the National Institutes of Health (NIH), supports research on AIDS, malaria, and other infectious diseases, as well as allergies and immunology. NIH and CDC are agencies of the United States Department of Health and Human Services.

Press releases, fact sheets and other NIAID-related materials
are available on the Internet via the NIAID home page at
http://www.niaid.nih.gov.

–Contributed by Michael Meredith, DVM, PhD