She and the health team at The Maschhoffs have shown M. hyo elimination can be successful and cost-effective.

The cost of living with M. hyo in a pig herd ranges from $3 to $10 per pig, depending on its stability and its co-infection potential with other health issues, like influenza or porcine reproductive and respiratory syndrome (PRRS). Hensch estimated M. hyo was costing The Maschhoffs about $5 per pig - “and that number would be conservative,” she added.

“Mycoplasma is something we can control,” Hensch said. “You don’t have to keep a herd negative for very long to pay back the money invested.”

In the beginning

In 2015, The Maschhoffs began to eliminate M. hyo in its multiplication herds. The business uses a multiplication pyramid so the health team started at the top and worked its way down to have a negative gilt source for its other herds.

“That’s the ‘Cadillac’ programme,” Hensch said. “We didn’t want to fail or wonder why a herd turned positive three years from now.”

M. hyo elimination is a long process. As The Maschhoffs started to have negative pigs coming out of the multiplication herds, it began stabilising its commercial herds.

“We started to ask, should we or should we not eliminate Mycoplasma?” she said. “That $5 per head was pretty enticing. We took our 220,000 sows at that time and put 90 percent of them on an elimination plan.”

Timeline

• Pre-2015: M. hyo-positive with extremely variable stability.
• 2015-2016: Elimination of M. hyo in the genetic base.
• 2016-2019: Elimination of M. hyo in almost all commercial sows.
  • Identification of elimination failures or re-breaks.
  • Capture lessons learned.
  • Final M. hyo-negative percent after closures (2020 – 92 percent).

A “standard plan” was used, but Hensch said there were variations on that plan across the 60-plus sow farms. It took one to one and a half years before re-breaks began to show up, in about 20 percent of the herds.

“We had a lot of lessons learned from those experiences and have since embarked back on those closures,” she said. “By 2020, we’ll have 92 percent of our females negative. We feel pretty confident this last round of closures will get us there.’’

Follow the steps

Farms were loaded with negative gilts, then those gilts were exposed to M. hyo so they were 100 percent positive, which was an important component of the plan. There were questions at the time on whether a sow farm would use aerosolised exposure (fogging of rooms) to M. hyo.

“At the time, we said ‘don’t do it’ - there were already a lot of positive animals and the herd was already unstable,” Hensch said. “We didn’t see the value in the beginning.”

Herd closure was between 35 and 40 weeks. Some herds were closed for PRRS, and M. hyo elimination took place at the same time.

Vaccination and medication plans - feed, water and injectable, as needed - varied with each facility. But generally speaking, Hensch said that between the sow herd and growing pigs, most herds were vaccinated for M. hyo “at least two or three times” and that all closures received an injectable antibiotic. Some herds were also treated with feed or water medications.

“There are a lot of options and, if you talk to 10 veterinarians, they’ll give you 50 different plans to close a farm, which is why we have so much variation [in vaccination and medication protocols],” she said. “You may not want to do water medication if you have trough waterers because you can’t dose properly and you’ll have too much wastage. Others may not be able to manage it in the feed because of their medication set-up.

“What I feel is a must is to be able to produce pigs as we go through an elimination programme,” she added. “The vast majority of our farms would have had breed projects off-site with negative animals that they would have continued breeding while the farm was closed.”

While details might vary, Hensch said there are certain activities that need to take place on specific days in the programme, so attention to detail is critical. Failed Mycoplasma closures are usually due to execution: “If you don’t execute on the plan, you’re not going to be successful,” she said.

Lessons learned

Producers will learn as much from their failures in M. hyo elimination as their successes, Hensch pointed out. Here are some of the key points The Maschhoffs learned:

• Establish Day 0: This is the day that indicates all gilts are positive. It’s critical because M. hyo can be shed for 240 days, which is 35 to 40 weeks of closure. If a naïve animal enters the herd and just one animal is shedding, that extends the 240-day closure.
• Deep tracheal swab: M. hyo is a difficult bacterium to find without performing a deep tracheal swab. However, this is invasive to animals and difficult to perform. The type of swab used can give different results too.
• Fogging protocol: The Maschhoffs have begun using fogging as a way to better establish Day 0. Lung tissue of a known-positive donor animal is mixed with a media solution and is aerosolised in the barn to ensure all animals are exposed.
• Closure length: Farms that chose 35-week closure were tied to the $10 per sow programme, so Hensch couldn’t say with certainty why some of these herds broke, but she did emphasise that herds choosing a 35-week programme must be “100 percent certain of Day 0.” If the status is unknown, Hensch recommends a 40-week closure.
• Medications matter: Some medications worked better than others on different farms. This is somewhat determined by age, ventilation and filtration systems of the buildings, as well as the level of biosecurity on each farm. The higher the pathogen load, the bigger the return on medications. “If you want to be more successful, you’re going to have to spend a little bit more money [upgrading facilities],” she said.
• Test beforehand: There is value in testing some of your sow herd prior to initiating an elimination programme to determine the herd’s stability.
• Management and buy-in: Identify detail-oriented managers to make sure important steps of the elimination plan are carefully followed. Make sure staff members understand the benefits of disease elimination and are willing to follow biosecurity procedures.
• Determine acceptable risk: Each operation must calculate its own return on investment, Hensch said.

Worth the effort

M. hyo elimination is a learning process, and new technologies like fogging will make elimination easier and potentially more successful by clearly identifying Day 0. The more herds that go through the process, the more the industry will learn about effective elimination protocols.

Hensch said owners/managers shouldn’t expect a 100 percent success rate, but the process is beneficial and cost-effective. “You have to be mentally prepared for the outcome, but even if it’s not completely successful, you’re still going to get a return on your investment,” she said.