It's hard to keep up with the changes and trends in today's pork industry. To help monitor what's happening, the Veterinary Service division of USDA's Animal and Plant Health Inspection Service is releasing its Swine 2000 Study.

State and federal veterinarians and animal health technicians collected data from 2,499 pork production sites, involving 2,328 operations. Included in the study were the top 17 pork-producing states, accounting for 93 percent of the U.S. hog inventory and 92 percent of U.S. pork producers running operations of 100 or more hogs and pigs annually.

Similar surveys have been conducted in 1990 and 1995, as part of the National Animal Health Monitoring System.

During the next several months, Pork editors will work with NAHMS staff to present a series of articles outlining the survey results. Presented in this first installment is a look at nursery productivity.
"The use of separate nursery sites has increased a lot since 1995," says LeRoy Biehl, consulting veterinarian for APHIS. "The same is true with segregated early weaning." The 2000 results show that on average, 50.4 percent of the sites have a nursery production phase. For those sites with a nursery, here's the type of facility that you
will find:

  • Total confinement – 75.9 percent (all sizes).
  • Open building with no outside access 8.2 percent (all sizes).
  • Open building with outside access – 12.3 percent (mostly sites with a total inventory of 2,000 hogs, with a few from mid-sized sites and none from largest group).

Biehl also points out that the survey showed that respiratory problems are the leading cause of nursery deaths. "If porcine reproductive and respiratory syndrome is involved you will have a problem," says veterinarian Daryl Olsen, AMVC Management Services, Audubon, Iowa. "If not, then you're probably dealing with high-health diseases, such as Streptococous.suis and Haemophilus parasuis."

Some producers are fortunate enough not to deal with a lot of respiratory problems. Take for example, Premium Standard Farms. "  treat a lot of E.coli.," ays Lisa Becton, PSF veterinarian, Princeton, Mo. "Once in awhile there's a bout of scours, but we haven't had a lot of respiratory problems."
Becton attributes PSF's lack of respiratory problems to preventive medicine. "We're trying to determine if we can reduce medication expenses and maintain a high-health status," she notes. For starters, Becton administers an oral non-pathogenic vaccine to the pigs when they come into the nursery. (The accompanying chart outlines the major causes for nursery mortality).

"As we focus on PRRS control in the sow herd, it helps reduce it in the rest of herd," contends Becton. "We're striving to maintain high-health herd replacements, which give you stable animals in and stable piglets out." To help find answers for some of the lingering problems in the nation's pork industry, the National Pork Board is helping fund a number of swine health research projects. While overall only 12.7 percent of the sites used early weaning, it was used by almost 70 percent of large sites.

"As more producers go to early weaning, we're recognizing new trends in the industry," says veterinarian Beth Lautner, NPB vice president of science and technology. "We're making early weaning health issues a high priority. We're specifically looking at Strep.suis, Haemophilus parasuis, enteric diseases and PRRS." For 2001, NPB is spending approximately $290,000 on all types of swine health research. This includes porcine respiratory disease complex, enteric disease syndromes, emerging diseases and syndromes, and biosecurity practices.

The average weaning age has dropped since 1995. "More than 92 percent of large sites wean pigs at less than 21 days old, whereas only 13.5 percent of small sites wean at less than 21 days," says Biehl. The national average weaning age for large sites was 18.7 days.

In 1995, the average weaning age was 25.1 days. Although weaning age declined as the site increased in size, age of pigs leaving the nursery was similar across size groups in the 2000 study – the average age was 63.3 days. (The chart above outlines the weaning age breakdown).

As the size of site increases, so does nursery pig mortality. In the 1995 Swine Study, an average of 2.4 percent of all pigs that entered the nursery died. That number rose to 2.6 percent in the 2000 study. Here's the breakdown by site size:

  • Small Site: 2.5 percent
  • Medium Site: 2.6 percent
  • Large Site: 3 percent

Olsen believes there are two issues that may have led to higher nursery mortality rates. The first deals with piglet age. He concurs with the study's findings that weaning ages have declined. "There's a lot of demand to push pigs out of the sow unit," explains Olsen. "When you wean younger pigs, you're creating a piglet that's more difficult to manage in the nursery. Plus, it creates a whole new set of management needs." For instance, a piglet that's 18 days or older has greater survivability and a better immune system vs. one that's less than 16 days old.
The second issue involves all-in/all-out pig flow. More producers are using this production practice, but unfortunately many producers running large sites are using all-in/all-out by room instead of by site. By doing this, producers can't depopulate and disinfect the entire site. Even if single rooms are cleaned and disinfected after each pig group, it doesn't help break a disease cycle if you have a shared hallway between nursery rooms. (The chart below outlines the breakdown of pig flow for the various producer size groups).

One of the keys to a successful nursery is the employees. Both Olsen and Becton focus on employee training. PSF offers intensive nursery classes that stress preventative management and maintenance, including proper sanitation to prevent disease introduction. In addition, Olsen believes it's essential to choose nursery employees with the right personalities to deal with this age of pigs. The employees need to be willing to take the time and work with the pigs, plus be dedicated to detail.
Overall, Olsen believes the industry is solving a lot of the nursery problems. Although, he contends it's still the most neglected area of pork production. Producers tend to concentrate on other areas, such as the sow unit or grow/finish pigs, and many times the nursery phase gets left behind. "A lot depends on the quality of pig that we're putting into the nursery," he says. "If we put in a big, healthy pig and have good management practices, the nursery is much easier to manage."

For more information about the Swine 2000 Study results, call NAHMS at (970) 490-8000 or check out the Web site at: www.aphis.usda.gov/vs/ceah/cahm