Parasites persist in hog production, especially in niche markets

Environmentally controlled hog facilities eliminated most swine parasites. But Ascaris suum (roundworm) continues to persevere on some conventional farms and frequently on farms for niche markets.

“Bringing pigs indoors onto slatted floors has decreased the overall prevalence of parasites in swine,” reported Laura Carroll, DVM, Four Star Veterinary Service in Elizabethtown, Pennsylvania. “But roundworms can still be a problem in conventional swine units.

“Niche production systems where pigs are raised on pasture or on solid floors with bedding are more prone to developing parasitic infections,” she said. In addition to roundworm, these farms can also face issues with Trichuris suis (whipworm).

Roundworm encounters

Roundworms continue to persist in hog systems because they are difficult to eliminate with common sanitation methods, Carroll explained. The adult female can lay up to 2 million eggs a day — eggs that are resistant to disinfectants and chemicals.

The clinical signs of roundworms may include a cough that is non-responsive to antibiotics, thumping, unthriftiness, poor hair coat, decreased growth rates and presence of adult worms in feces. On necropsy, the most prevalent lesions are milk spots on the liver due to larval migration of worms and detection of adult worms in the small intestine.

“Roundworms can cause decreased growth rates and feed efficiency, and increased mortality — particularly in younger animals,” Carroll said. “They can also cause liver condemnation and decreased carcass value at slaughter plants.”

Roundworm treatment

Carroll recommends routine monitoring for roundworm on all sow farms, both conventional and niche. Roundworm eggs can be detected either in fecal samples or oral fluids.

“In our niche production systems, we detect roundworm eggs in probably 75% of the samples,” she added.

“Depending on the severity of the infection and management goals, we may implement a mass herd deworming program or manage with a strategic control program at critical time points based on prepatent period of the worm and type of anthelmintic used.

“At the sow farm level, this could entail administering an anthelmintic to gilts just prior to introduction into the sow herd and deworming sows 2 to 3 weeks prior to farrowing,” Carroll explained. “Sows can transmit roundworms to their piglets…deworming sows a couple of weeks before farrowing prevents them from contaminating their pigs.”

Several anthelmintic products are available for roundworm treatment and control. Carroll recommends working with a veterinarian to determine which one is most appropriate for their herd.

“Anthelmintics can vary in their spectrum of activity,” she explained. “Some are effective at eliminating the mature (adult) worms but not effective against immature worms. Depending on what’s going on at your farm, one product may be preferred over another. If the appropriate product is used and it is administered at the correct timing interval, then generally we have a good response to treatment.”

In addition, increased sanitation and washing sows pre-farrow to remove feces will help reduce the number of roundworm eggs in the environment which may subsequently infect piglets.

Whipworm issues

Niche production systems also are more prone to whipworms than other hog systems, Carroll said. These parasites are more difficult to detect because females are sporadic egg layers. Infected pigs may not be passing eggs when a fecal sample is taken.

The clinical signs are more obvious than roundworms. Young pigs will have mucohemorrhagic diarrhea and exhibit signs of wasting and lethargy; there will also be increased mortality. Diagnosis on necropsy is the presence of worms in the large intestine and cecum.

“If whipworm eggs are found, we implement treatment with an anthelmintic that’s effective,” she said. “There are less products effective against whipworms than roundworms. So it’s important to discuss with your veterinarian what’s effective.

“We also work hard to clean up the facility as much as possible. Disinfect between groups, but it is still difficult to control because the eggs are very persistent in the environment.” The eggs can remain viable for several years in favorable conditions.

“Control can be challenging based on the facility design, solid floor, pastures,” she added. “We do pasture rotation to minimize how many worms are shed into the environment.”

In herds where whipworms are established, Carroll uses an anthelmintic as a preventative to keep whipworm levels lows. All new groups of pigs added to the herd are treated.

“Prevention is the key to parasite control,” she said. “This goes back to having a good relationship with your veterinarian and making sure you have good control programs in place to minimize the transmission and keep the burden level as low as possible.”

 

 

Tools for managing pigs without antibiotics

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Raising pigs without antibiotics requires extra management and different tools compared to traditional commercial hog production, reports Laura Carroll, DVM, veterinarian with Four Star Veterinary Service, Elizabethtown, Pennsylvania. Carroll works with many hog producers who raise pigs without antibiotics for specialty markets.

“We’ve found with antibiotic-free production that the basics are much more important — feed, water and air,” she explained. Things like proper ventilation, access to feed, an adequate supply of water, the right number of nipples for pigs in the pen all become very important.

“Vaccination is another component,” Carroll said. “Commercial and autogenous vaccinations are utilized quite a bit to make sure we’re preventing these disease challenges from occurring.”

Veterinary oversight

While Carroll believes it’s important for all producers to work with their veterinarians, hog farms not using antibiotics will need a little more veterinary oversight.

“We certainly want to make sure we’re on top of any disease challenges as they arise, just because we are limited in the tools in our toolbox that we can utilize,” she explained.

“We have to be a little bit creative in terms of managing pig health and figuring out ways to produce high-quality pigs,” she added.

Adding acidifiers

One tool Carroll and her associates rely on to help baby pigs get a good start is acidifiers. The product is fed on creep feed in the farrowing house.

“We use acidifiers mostly to reduce the pH in the GI (gastrointestinal) tract to make it a more acidic environment,” she said. “Some of the harmful bacteria we deal with like to live in more alkaline, more basic environments. If we can provide an acidic environment to the pigs, then we’re reducing the growth of this potentially harmful bacteria.”

Acidifiers also help newly weaned pigs break down feed in their gut because they lack the ability to produce enough acid to do it themselves.

“If we can provide some acidifiers to the diet or through water, then we’re making digestion a lot easier on that pig,” she explained. “Weaning can be somewhat stressful, and this really helps get these pigs started.”

Prebiotics and probiotics

Carroll uses prebiotics and probiotics to maintain a balance of good and bad bacteria in the GI tract.

“Prebiotics are used to help promote the growth of that good bacteria, almost like fertilizer for the good bacteria in the GI tract,” she explained. “Probiotics are the good bacteria themselves. Lots of times these are live culture or live organisms that we are utilizing.”

Both products are used in times of stress, including enteric disease challenges and weaning, when there’s a disruption in the gut microflora.

Nutritional supplements

“We utilize nutritional supplements in many cases when pigs just aren’t feeling well,” Carroll said. “It could be from the stress of weaning, for example, or when they’re undergoing disease challenges.”

This is especially true for younger pigs who don’t have a lot of energy reserves to use when sick.

“In cases of diarrhea, there could be a lot of fluid loss,” she said. “We need to try to replace those electrolytes, replace the nutrition in these animals and keep them hydrated so we can keep them going. Nursing piglets and weaned pigs require a lot of energy to nurse and to get up to the feeder and drinker.”

Crossover to commercial

Depending on the situation, Carroll prescribes these products in commercial systems, too.

“We utilize a lot of these products, either to replace some antibiotics or in conjunction with antibiotics,” she explained. “They’re a nice supplement.

“And certainly, from an animal-welfare standpoint, I think it improves how we’re handling our pigs when they’re going through some stress.”

Veterinary oversight continues to be important to make sure these products are used correctly, Carroll added.