How to tackle mortality-causing lameness in finishing hogs

Lameness is now the leading cause of mortality in mid- to late-finishing pigs. How did lameness develop into such a big problem?

Mike Eisenmenger, DVM, Swine Vet Center, and Kathleen Wood, DVM, Christensen Farms, addressed the lameness issue during a recent webinar produced by the Swine Health Information Center. Both shared insights from their experiences managing lameness in finishing hogs.

First, pathogens that used to drag down finishing pigs are under control. “We worked really hard to remove the major pathogens that flow out vertically from sow farms,” Eisenmenger reported. “We want to be able to give the nursery-grow-finish system PRRS- (porcine reproductive and respiratory syndrome) and Mycoplasma hyopneumoniae-negative pigs so we can get the lowest mortality possible.

“In reality, even though mortality has improved, it seems we hit a baseline threshold. It is getting harder and harder to make continuous improvements…and there are a multitude of reasons.”

Lameness caused by bacterial arthritis has become the big reason for mortality today. Eisenmenger credits the infectious “small bugs”— Strep suis, Mycoplasma hyorhinis and hyosynoviae, Actinobacillus suis, Glaeserella parasuis — for the arthritis.

25% to 40% lameness new normal

Industrywide, lameness affects 10% to 25% of hogs in grow-finish. But Wood was stunned to see how much lameness increased during the COVID-19 shutdown.

“It has been on the upward trend in the summer months,” Wood said. “Recently 25% to 40% severe stiffness or lameness is not uncommon. Lameness is the No. 1 cause of mortality in our mid- to late-finish hogs. Unfortunately, it has become the new normal.

“Mild lameness has always been there,” she continued. “We just weren’t recognizing it as an issue because it doesn’t raise red flags as a cause of high mortality. Stiffness and subtle lameness aren’t alarming, and they don’t trigger the need for immediate treatment in the industry. But we need to change that. We need to start reacting to low-level mortalities.”

Back to basics: necropsy it

A focused, coordinated effort to reduce lameness by Christensen Farms started with the veterinary team going into the field and regularly working with service staff on necropsies to help identify causes for stiffness and lameness.

“Our service team is very well trained, but there are still nuances and additional things that they can learn about on causes of lameness and post-mortem exams,” Wood explained. “We started cutting open a lot of pigs with them and getting our team to open pigs on their own. They weren’t confident cutting open joints, so we walked it through with them.

“It’s not always about just the heart, lungs or brain,” she added. “If a pig can’t walk properly, it’s chances of making it to market as primary pig has severely decreased. This means that getting into the bones and seeing what’s going on is an obvious but underlooked necessity.”

The results of the additional training are a game changer for Christensen Farms, she added. It reset what the farm’s service teams expect with lameness.

“Pigs are not supposed to be stiff,” Wood said. “Lameness and stiffness are not normal. Pigs are not supposed to be in pain when walking.”

Treat early signs

The second part of the Christensen Farms plan involves early recognition of lameness, with a priority placed on treatment.

“We have to do what’s right for the pigs,” Wood said. “Treat them. We are limited in our options, especially with anti-inflammatories. But they are equally as important as antibiotics and give pigs pain relief. In our system, we are limited to two, and there are withdrawal times that make it difficult to use them in late-finishing pigs.”

To help caregivers identify when to treat, Wood created a chart with photos of pigs showing three stages of lameness, with the required treatments. The chart helps farms quickly identify when help is needed.

Work with diagnostics

Another part of the lameness fight means working closely with the diagnostic lab. Wood wants all lameness samples sent to the lab with a detailed history and other communications of the problem to help the lab more quickly find the cause.

Also, samples sent to the lab should be the entire limb and not be fluid from an open joint. Conditions in the barns are not sterile enough to collect the fluid, according to Wood.

Other interventions

Wood also works with other departments at Christensen Farms to determine the best treatment options. For example, she suggests working with the marketing group if 5 days are needed to provide medication with a withdrawal time to get on top of a lameness issue.

Another department that can help with lameness issues is nutrition. “Nutritionists are your friends, not enemies,” Wood said. “Ask them what we can do to make this better and be open to their suggestions. Spending time with them in the field is a great way to get aligned on the issue.

“And don’t forget the sow farm,” she added. “What are they selecting for on confirmation? What can we do to knock down their bug load? How about maternal immunity? Everything goes downstream.”

 

 

Time to invest in market-transport biosecurity

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Grow-finish farms are the last segment of hog production to enact strict biosecurity protocols. That needs to change, reports Mike Eisenmenger, DVM, Swine Vet Center, St. Peter, Minnesota.

“We had to stabilize the health in the sow system first,” Eisenmenger said. “Companies invested millions into the sow farm…all to make a really healthy pig that we can flow downstream.

“But now, it becomes critical that we increase the biosecurity of the grow-finish system as we’ve made all those investments in the [sow] system,” he added.

Market-transport issues

A major biosecurity risk for grow-finish farms is the transport of hogs to market.

“We invest a ton of money and effort into getting transportation right when we haul gilts, move sows, haul weaned pigs and haul nursery pigs,” Eisenmenger said. “But when we get the finishing barn off to the market, that’s where we still have a long way to go.”

Increasing biosecurity for grow-finish is tough due to the sheer number of facilities. For example, one sow-farm system may have anywhere from 10 to 40 locations. “Now you branch off into the nursery/grow-finish world and you’ll have hundreds and hundreds of locations that may be scattered across multiple states,” Eisenmenger explained.

“Just the sheer diversity of geography and [being] able to keep your eyes focused on all areas at the same time is a big challenge.”

No-risk trucking

In reality, transporting hogs to market should pose no risk to the farm just like trucks used to transport sows and gilts, Eisenmenger said.

“I have complete confidence that we can take a truck that’s hauled infected pigs, bring it in and get it cleaned up, disinfected, baked and heated; and it’s pathogen-free,” he said. “Now suppose we could do that with all our market trucks.”

Here’s how Eisenmenger envisions it: A clean market truck brought onto a finishing site would be cleaner than the barn. The trucker remains in the cab while the barn employees load the hogs on the truck. The trucker drives to the packing plant, remains in the cab and allows the plant employees to unload the hogs.

The trucker then drives to a truck-wash facility to drop off the trailer and drives the tractor through a car-wash-type facility. At that point, the trucker is ready to pick up another trailer that’s been flushed, power washed, disinfected and baked.

“We know from previous experience and testing hundreds of trucks that we can get them clean after they’ve hauled infected pigs,” Eisenmenger said. “We know how to do it and we know what to build. The last step is who’s going to build it…who’s going to run it, provide oversight and audit the facility?”

Two market-transport scenarios

Two truck-wash strategies appear to be developing in the industry.

“One is going to be the pig farm or company owns it, runs it and controls it,” he said. “Or two, I think you’re going to leave it up to the individual private entrepreneurs who want to build it, and [pork] producers contract with them.”

He envisions a truck-wash facility with a pool of clean trailers ready for truckers to take back to a farm for another load to market.

Of course, there are issues to overcome like turn-around time for the trucker. Currently, trucks can leave a packing plant immediately after unloading and head home to get another load in a few minutes.

Another issue is most contract truckers own their tractor and trailer.

“This would be a completely new concept,” Eisenmenger said. “It’s like you don’t own the trailer. It’s just in this pool of trailers and they’re all the same. Drop off a dirty, pick up a clean and head back out. So that’s another step to clearly overcome.”

Payoff? Better pig health

Eisenmenger remembers when biosecurity in sow systems was poor, which led to poor sow health. After decades of work, biosecurity in sow units is greatly improved and sow health is robust, he adds.

“I still believe that we underestimate the cost of poor biosecurity…on a regular, routine basis in the nursery/grow-finish system,” he said.

Eisenmenger considers grow-finish biosecurity a very important tool in the toolbox to keep “diseases that we currently have in this country out of our finishers. [Then] we’re going to be much healthier, happier and, obviously, use less antibiotics in treatments.”

 

Veterinarian says VFD led to more strategic antibiotic use

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The Food and Drug Administration’s revised rules for antibiotic use in hogs, including the veterinary feed directive (VFD), has led to a reduction in and more strategic use of antibiotics in swine.

But getting to this point required trial and error to determine what was and wasn’t needed, according to Mike Eisenmenger, DVM, Swine Veterinary Center.

Pulled many antibiotics

Eisenmenger and his clients decided to use the new VFD rules as an opportunity to figure out exactly what antibiotics are needed. They removed most antibiotics including those used in nursery feed, routine sow pulses and injectables at farrowing.

“What we found was both good and bad,” he admitted. “Some of those antibiotics were truly needed.”

One example is in the farrowing house where they stopped giving antibiotic injections during processing.

“Over the next 6 months to a year, we noticed in a lot of the systems that preweaning mortality was going up,” Eisenmenger said. “When we went back and explored the reasons, there were a lot of joint infections occurring around the time of those surgical procedures.

“Just like humans going through a surgical procedure, it is appropriate to have some antibiotics on board,” he explained. “We’ve gone back to placing antibiotics at the time of surgical procedures in farrowing.”

Antibiotics used strategically

When the VFD was first announced, Eisenmenger admitted he was concerned. “Am I going to be a veterinarian that’s just signing a bunch of paperwork?” he asked.

“But this was good for us. It made us stop and reflect on all the programs that we’re doing and [understand] which ones were really needed.”

Antibiotics are now used more strategically. In very healthy pig flows, antibiotics are not used. But if mortality starts to creep up or a minor welfare issue arises, antibiotics are introduced.

These decisions are made with clients during quarterly meetings where they review all feed-grade antibiotic programs and other antibiotic needs.

Preserve a precious resource

“We’ve learned that antibiotics are still extremely important to pig health,” Eisenmenger said. “Our job is to take what I would say is a precious resource…and do our best to use it most appropriately.”

Right now, he is not supportive of antibiotic-free hog production, especially with current disease challenges in the hog industry. “I’m hoping we are not forced to go to that direction,” he said.

“We want to preserve the right to use antibiotics, and if we do it in a responsible way, which I think we are under the VFD prescription process, it’s something that can continue in the future,” he added.