A Strategy to Battle Respiratory Complex

STOMP is a diagnostic program that pinpoints when pigs are becoming infected with respiratory pathogens so medication can be placed when it will do the most good.One sure way a veterinarian creates trust and confidence with clients is by establishing a herd health program that keeps pathogens low.David Striegel, DVM, Animal Health Center, Sac City, IA, knows firsthand the frustrations of battling

STOMP is a diagnostic program that pinpoints when pigs are becoming infected with respiratory pathogens so medication can be placed when it will do the most good.

One sure way a veterinarian creates trust and confidence with clients is by establishing a herd health program that keeps pathogens low.

David Striegel, DVM, Animal Health Center, Sac City, IA, knows firsthand the frustrations of battling a tough opponent like Porcine Respiratory Disease Complex (PRDC).

"We have a tremendous number of grow-finish operations in our area," Striegel explains. "PRRS and Mycoplasmal pneumonia are two of our biggest health challenges."

Combine these challenges with the large number of pigs in the area and few geographic barriers, and control becomes even tougher.

"Most of the disease problems I deal with are multi-factorial," says Striegel. "That's why it's so important to have a thorough understanding of the disease dynamics of the herd.

"With this understanding, medication can be strategically placed for more efficient control of the disease complex."

Below the Threshold "Over time, a herd infected with a pathogen such as mycoplasma will shed and transmit pathogens until a threshold level is reached and clinical respiratory disease appears," explains Gary Bosch, DVM, Pharmacia & Upjohn Pork Strategic Business Unit.

In the face of respiratory disease, a control program should be implemented to keep the pathogen load below that threshold throughout the production cycle, he adds.

Figure 1, for example, shows what happens in a herd infected with a pathogen such as Mycoplasmal pneumonia. Over time, pigs shed and transmit pathogens until a threshold level is reached and clinical respiratory disease appears. The goal of the control program is to maintain the pathogen load below the threshold level until the pigs go to slaughter.

Similar observations come from Craig Pfeifer, DVM, Veterinary Medical Center in Worthington, MN.

"It's important to determine the approximate time frame when the disease is occurring," he says. "Then correlate your vaccination and antibiotic schedule to the time of infection.

"The goal is to place medication at or just ahead of the greatest spread of disease, but placing the treatment late enough to remain effective all the way to market," Pfeifer says.

The results, Bosch says, "are shorter treatment periods and reduction in the overall pathogen load, because action was taken prior to clinical outbreak of disease."

Strategic Placement Proper placement of feed medication is crucial in controlling PRDC.

For example, if medication is fed in the early nursery but PRDC occurs in the late finisher, the medication will have little effect. Moving treatment to the later feeding period has greater potential to suppress disease throughout the entire feeding period.

Figure 2 shows two possible intervention strategies. If medication is fed in the early nursery, PRDC can occur in the late finisher, as the disease has an opportunity to build momentum after the medication withdrawal. The later feeding period has better potential to suppress the disease for the entire feeding period.

Another treatment regimen shown to be effective is pulse dosing. Optimally, medication must be given long enough to suppress the disease and frequently enough to prevent the pathogen load from crossing the threshold level.

Figure 3 illustrates the pulse dosing treatment method.

"Putting medication in the right place for the right period of time will give a producer the highest rate of return," Bosch adds.

Targeting Disease Thresholds To enable producers and veterinarians to determine when disease thresholds are occurring, Pharmacia & Upjohn Animal Health has developed Serological Targeting of Medication Programs (STOMP).

"STOMP was designed to encourage pork producers, their veterinarians and animal health consultants to work together to develop a strategy for control of PRDC, especially focusing on mycoplasma within that complex," Bosch explains. "The idea is to investigate the disease dynamics within the pig population and from there develop a plan to place medication in the most strategic position that will deliver the best results.

"Also, we want to target a point where we are seeing the greatest spread or early colonization of the lung - which is not the same time as when we see clinical outbreaks."

Four-Step Strategy Both Pfeifer and Striegel have used STOMP's four-step process:

Step 1: Observe the whole herd for signs of respiratory disease. Conduct a walk-through. Check for clinical signs of disease such as coughing, thumping, decreased appetite and poor performance.

Step 2: Perform individual postmortems. This examination aids in identifying pathogens and determining antibiotic susceptibility.

Step 3: Conduct blood serum tests. Antibody response indicates exposure. To determine the time of exposure to pathogens, samples are taken from pigs in various age groups. Recommended check points are at 6, 10, 14, 18 and 22 weeks of age.

Step 4: Conduct PCR (Polymerase Chain Reaction) tests on a sample of pigs. This information is used to evaluate the interaction of PRRS and mycoplasma and to determine when the actual spread of pathogens takes place.

Four Disease Patterns "The STOMP program has led to the development of a 137-herd database," Bosch points out. "Among these herds, four common patterns of mycoplasma infection have been observed."

The pie chart in Figure 4 illustrates the percentage of these herds with the four common patterns.

Each pattern calls for a different feed medication protocol. The medication is used to control the severity of mycoplasma.

Pattern 1 of PRDC serology: early nursery exposure:

- High rate of sow-to-pig infection;

- Pattern of early circulation of mycoplasma in the nursery; and

- PRDC not a major complaint in finisher.

Feed medication recommendation: pulse dosing, with the first pulse in the mid-nursery phase (5 to 6 weeks of age), and the second dose after pigs move into the finishing phase (10 to11 weeks of age).

Pattern 2 of PRDC serology: mid- to-late nursery exposure:

- Fewer pigs infected in the early nursery, so disease takes longer to spread; and

- PRDC shows up in pigs at 12 to 16 weeks.

Feed medication recommendation: medicate during active transmission and colonization, from late nursery through early finishing.

Or, follow a pulse dosing program with first dose in late nursery and second dose at 13 to 14 weeks of age.

Pattern 3 of PRDC serology: finisher exposure:

- Stable sow herds;

- High disease transmission when pigs are moved to the finisher; and

- PRDC occurs at 16 to 20 weeks (18-week wall).

Feed medication recommendation: treat during the first three weeks of the finishing program.

Pattern 4 of PRDC serology: low exposure:

- Stable sow herds/PRRS negative; and

- No PRDC due to PRRS and mycoplasma.

Feed medication recommendation: Medicating for PRDC may not be necessary, but may be recommended for enteric disease.

Bosch says: "Understanding which pattern is present in a herd and basing the medication program on this observation will give a producer maximum impact for his dollars invested."

Team Effort Rusty Kosky, production manager of Newell Pig Co., a pig management enterprise based in Newell, IA, says: "In the past, we were putting out fires. It was discouraging because we didn't know exactly what disease we were fighting."

He adds: "We started at ground zero 3 11/42 years ago, and today we manage close to 130,000 head of pigs. As a group of independent producers and investors, we knew that to grow and be profitable, we needed to work with our veterinarian, Dr. Striegel, and implement an effective health program."

Striegel says: "Using STOMP seemed like a perfect way to positively identify our challenges and nail down some of the problems we couldn't document with postmortem examinations."

Data Interpretation He goes on to say: "After evaluating the situation, we observed depressed performance in 100% of pigs, specifically the classic 18-week wall. It seemed like we were facing challenges from mycoplasma and PRRS and possibly swine influenza virus."

Serology tests proved his speculations to be correct. Data illustrated a high rate of disease transmission in the early finisher stage, with mycoplasma titers climbing through the 12- to 16-week period.

Also, it was found that 100% of the samples tested positive for PRRS during weeks 20 to 24, and mycoplasma titers spiked dramatically around 24 weeks.

"We knew the health status of the sow herd was stable," Striegel explains. "Now we could pinpoint the exact time of exposure.

"Based on program recommendations, we implemented a Lincomix Feed Medication program into the early finisher ration."

Kosky says right from the beginning they noticed at least a 15% improvement in average daily gain.

"The number of lightweight pigs has dropped from 60 to 80 head per group to 15. Our death loss rate also has significantly improved," he says.

Striegel notes his number one goal with STOMP was to improve the overall consistency of closeouts. And that's what happened.

Proactive Financial Rewards Improved herd performance is a positive. But there are financial rewards, too.

"We spent less money by strategically placing the medication prior to the outbreak of disease rather than merely reacting after we had a problem," Striegel explains.

Pfeifer agrees: "When we factor in the added value relative to increased performance after using this program, we've seen a $3 to $4 return for every dollar spent."

Kosky and his colleagues know that to remain competitive in today's industry, they must closely monitor their margins. It's wise business sense, and more importantly, it's their livelihood.

"Before, we were spending an extra $1.50 to $2.00 per head on various medications, and nothing worked," Kosky recalls. "Now, if we do need to treat, it actually works.

"Half the medication cost, plus the positive results when you do have to treat - that's the real difference."