NAHMS new swine reports cover vaccination, antibiotic practices, biosecurity

Fort Collins, Colo.-The National Animal Health Monitoring System (NAHMS) just released a new report that says vaccinating swine to prevent disease is a common management practice among U.S. swine producers.

Table 1 - Percent of sites that vaccinated breeding females for PRRS, Mycoplasma or influenza in the previous six months, by site size

The information was recently gleaned from its national study Swine 2000, which represented 94 percent of the U.S. pig inventory and 92 percent of U.S. pork producers with 100 or more pigs. The study results were from 2,499 swine production sites.

NAHMS says that the choice of vaccines administered depends on the risk of disease, stage of production and age of the animal.

The in-depth look at vaccination practices was coupled with two other NAHMS information sheet releases including pork quality assurance and biosecurity, reports Dr. Eric Bush, a swine epidemiologist with NAHMS.

Vaccination practices

When the 2000 results were cross-tabulated with results from 1995, the study shows a remarkable similarity with vaccination practices against Porcine Reproductive and Respiratory Syndrome (PRRS). The surveys showed that 28.3 percent of operation vaccinated against PRRS, and the 1995 total was 27.7 percent.

"The PRRS vaccine was used more frequently on sites with breeding females (37.1 percent of sites) than on sites with weaned market pigs (5.2 percent of sites). This accounted for 53.5 percent of all breeding females and 6.4 percent of all weaned market pigs," the survey reports.

Additionally, when the data is pulled by the number of breeding females, larger operations vaccinated against PRRS more frequently than smaller sites. (See Table 1.)

Autogenous vaccine was used on 7.4 percent of large sites (500 or more sow and gilt inventories).

Other results of vaccination practices include:

• Forty percent of sites with weaned market pigs vaccinated agains Mycoplasma pneumonia. This accounted for 62.8 percent of all weaned market pigs.

• Only 20.9 percent of sites with breeding females vaccinated against Mycoplasma pneumonia.

Larger sites were also more likely to vaccinate against Mycoplasma pneumonia in comparison to small sites, NAHMS reports.

Of those sites with breeding herds that used SIV vaccine, the majority vaccinated breeding females against H1N1 (71.4 percent) or against H3N2 (75.5 percent) at the time of entry into the breeding herd.

Overall, 11.2 percent of sites with breeding females administerd the H1N1 vaccine to these pigs, NAHMS says, during the previous six months. About 10 percent of respondents administered the H3N2 vaccine. And among all sites either breeding females, 7.6 percent used both vaccines.

Good management

NAHMS also released some data on management practices in the handling and use of animal health products. About 78 percent of the study's participants indicated they had completed the National Pork Board's Pork Quality Assurance (PQA) program. These sites had 87.5 percent of all U.S. pig inventories.

NAHMS says, "Good production practices include keeping accurate records on drug administration so that treated animals can be identified and tracked and proper withdrawal times can be observed." The survey says that two-thirds of respondents kept records on drug use. (See Table 2.) Many more large sites (98.6 percent) and medium sites (89.3 percent) kept records on drug use than small sites (63.6 percent), NAHMS reports.

Table 2 - Percent of sites that recorded information for antibiotics given to grower/finisher pigs

For large sites that used antibiotics to treat diseases in grower/finisher pigs, about three-quarters of respondents recorded drug names, treatment dates and doses. Pen identification was more often recorded than individual animal identification following the use of antibiotics in grower/finisher pigs, the survey says.

Biosecurity

Biosecurity is threatened with the introduction of new animals into a herd. Therefore, isolation of new animals can help minimize risk, Bush says. Two out of three small sites (less than 250 breeding females) either isolated new introductions to the herd "almost always" or "sometimes". The numbers steadily rose by size of operation. For medium sized sites (250-499 breeding females) 78.8 percent isolated almost always or sometimes, in comparison to 84.3 percent of large sites (500 or more breeding females).

Large sites tended to isolate new arrivals longer than small sites. The survey says that new breeding females were isolated for an average of 35 days on small sites as compared to 51 days for large sites.

For more information go to: www.aphis.usda.-gov/vs/ceah/cahm.