Fine-tune nursery management to achieve optimal pig performance

By Kate Ayers
Better Pork

 

Meeting new people, trying new food, and exploring a new destination can be exciting but daunting experiences that we encounter. Now imagine combining all three experiences into one day.

It would be justifiable for anyone to feel apprehension about leaving the comforts of home for so much “newness.” Young pigs face new litter mates, feed and environments when they enter the nursery. These stimuli can be inherently overwhelming and stressful.

Fortunately, swine producers work hard to ensure the health of their herds and provide a smooth transition into the nursery.

Success in the nursery can be attributed to supporting the development of “bulletproof pigs that get off to a good start, have a lot of antibodies, and can handle the immune challenges that they face in the nursery. Piglets that have antibodies are often less susceptible to scours at farrowing and post-weaning in the barns,” says Dr. Laura Bruner, a veterinarian at

the Swine Vet Center in St. Peter, Minnesota.

“After weaning, we want the piglets to just focus on eating, not rotavirus, strep or any other diseases. We want them to hit the ground running. So, preparing for the nursery phase is important.”

This month, Better Pork speaks with Bruner, swine nutritionists, and other sector specialists to learn how pork producers can level up their nursery management skills and overcome pig health challenges during this critical production phase.

Before the nursery

Optimizing health and performance in the nursery begins in the farrowing room and, more specifically, originates from sow comfort and milk production.

“This process starts six weeks before the piglets are born. We get the sow ready to produce the highest amount of antibodies that she can and make sure she is in the right condition, so that when the piglets are born, they are set up for success,” Bruner says.

Colostrum antibodies help prepare the piglets for farrowing and then the transition into the nursery.

Once the piglets are born, “make sure sows are eating well and producing lots of milk to optimize piglet growth while they are still suckling,” says Dr. Lee-Anne Huber. She’s an assistant professor in the department of animal biosciences at the University of Guelph in Ontario. Her research focuses on swine nutrition.

Producers can help “piglets prepare for life without mom and the comforts of the farrowing crates,” says Dennis Robles, the production specialist for Swine Health Professionals in Steinbach, Man. The company helps producers develop herd health plans, monitor production progress, and maintain biosecurity targets.

For example, “exposure to small amounts of creep feed after their second week of life will help familiarize the piglets with the first-stage ration that they will get in the nursery,” says Dr. Tim Blackwell. He’s a lead veterinarian in the animal health and welfare branch of the Ontario Ministry of Agriculture, Food and Rural Affairs and is based in Elora, Ont.

Huber agrees that creep feed can help make nursery transition easier for piglets.

Producers can “offer a highly digestible and palatable diet to the piglets that only they can access. The young pigs can then learn how to eat away from the sow.

“Not all piglets will participate and, if they do, it does not always translate to heavier weaning weights. Typically, though, piglets that do eat creep feed will have higher feed intakes after weaning,” she says.

Indeed, “heavier pigs at weaning will reach market weight sooner than lighter pigs,” Huber says.

“An old rule of thumb is that if a piglet weighs 100 grams (3.5 ounces) heavier at weaning, it will reach market weight half to a full day sooner than lighter pigs. This fact motivates us to set up pigs with solid weaning weights.

“In addition to creep feeding, producers can provide piglets in the farrowing room with a water source, such as a cup or nipple drinker that is close to the floor. The drinker teaches piglets that feed and water don’t always come from the same place as it does when they suckle the sow. If you can teach them that aspect ahead of time, you’re already a step ahead,” Huber says.

Weaning age can also play a significant role in the well-being and success of piglets in the nursery.

“Wean age is huge. The older the pig, the better it handles stress of transitioning from farrowing to the nursery,” Bruner says. “And the better the pig takes off in the nursery.”

Traditionally, weaning age is 21 days, but shifting to 24 days, for example, can help piglets put on more weight and thrive in the nursery, says Dr. Crystal Levesque, an associate professor of swine nutrition at South Dakota State University.

In operations that require transportation to another farm location, staff members can help reduce weaning stress through gentle handling, “moving pigs in a calm manner, preventing overcrowding, and loading them into a clean, disinfected and dried or baked trailer,” Robles says.

Clean and chemical-free shavings are better for footing, and trailers should have appropriate covers to protect the pigs from outside conditions, he adds.

Before piglets enter the nursery barn, producers should take extra care ensuring that “the room has been adequately washed, disinfected and dried before a new group of weaned pigs arrives. Farmers should be attentive to the removal of organic materials on floors, walls, pen dividers, gates and pins, and other surfaces,” Robles says.

Producers must use “disinfectants according to manufacturers’ accurate dosages and allow enough time for the disinfectant to work effectively. Also, never underestimate the process of drying the room or barn to provide the new batch of pigs with a truly clean environment.”

As part of pen or barn preparation, temperature is also an important factor to consider. “A day before the pigs arrive, warm the room to the nursery entry temperature, which is between 29 and 31 C (84 and 88 F). This preparation will help them get off to a great start. Indeed, correct ventilation and environmental settings must be in place even before the first hoof steps into the barn,” Robles says.

Solid start

Newly weaned piglets may experience environmental, social, nutritional and physiological stressors during their transition to the nursery. As a result, producers should keep watchful eyes on their newcomers to identify piglets that may get off to a slow start.

“The first two to three days in the nursery are the most critical as the piglets adjust to a new environment,” Blackwell says.

Producers can use qualitative or quantitative measurements to monitor pig health and progress, he says.

“My favourite metric is feed intake. Depending on the weaning age, which is commonly around 21 days, I like to see 400 grams (14 ounces) of feed disappear per pig in the first 48 hours. A little bit more if you wean them later and a little bit less if you wean them earlier,” Blackwell says.

Studies show “that 85 per cent of newly weaned pigs take approximately 35 hours to find water and 90 per cent of them take 30 hours to find feed,” Robles says.

Indeed, some pigs may go without food for a substantial duration, Levesque says. “This length of time without anything going into the gut can increase risks of diarrhea, infections, coughs, or flu. It doesn’t take long for the gut to weaken,” she says.

To ensure that pigs consume enough feed and water as soon as possible after entering the nursery, farmers can use several tactics.

One approach is to wait a couple hours and allow the piglets to settle into their new home before feeding the pigs their first meal.

“When piglets are weaned from litters into bigger pens with multiple litters, there is an enormous amount of distractions for them. They investigate the pen and pen mates and figure out where the water and heat are located,” Blackwell says.

“There are just too many other distractions in those first two or three hours. If feed is already in the feeder, it gets stale and the pigs don’t key in on it because there are so many other things going on.”

Mat feeding can help piglets find feed and become more comfortable.

During “the first five to seven days in the nursery, this feeding strategy allows the pigs to sort through the feed. In farrowing, eating is a social event. So, if pen mates see pigs gathering in one spot, they’ll be curious and want to see what is going on,” Bruner says.

Pigs also become accustomed to a signal at feeding time.

“For the first few days, that signal could be a caretaker coming into the pen to deposit feed. Staff members can then more easily identify pigs that are laying down or not interested in the feed, and you can provide additional support to those pigs,” Blackwell says.

Farmers who closely monitor their herds can identify lighter or weaker pigs and provide the extra care they need to thrive.

“Curious and hungry pigs who ate creep feed will come up to the feeder pretty quickly. They will encourage other pigs to come up with them. This time is a good opportunity for producers to see which pigs do not come up to the feeder and to help them,” Blackwell says.

“If you have a group of lighter pigs, they should go in their own pen. You can keep an extra eye on those animals,” he says.

Feed types

The number 1 factor to get piglets off to a solid start in the nursery is to get them to eat, many experts say. To ensure that piglets consume adequate levels of nutrients, the feed must taste good and be fresh.

Typically, nursery diets are highly palatable with high inclusions of “animal proteins, such as fish meal or milk products, which help piglets transition from a milk-based diet to solid feed that is primarily made up of plant protein,” Huber says.

Producers must examine nutritional, feed and management factors in their operations and identify any gaps or areas that they can improve.

“After piglets are weaned, they often experience a post-weaning growth lag” from stress and changes in diet and the environment, Huber says. “They also have immature digestive tracts. Their stomachs are not as acidic as older pigs, and their digestive enzymes are not as active.

“If you can shorten that postweaning growth-lag period, pigs may reach a heavier weight sooner and could have higher exit weights,” she says.

“Producers can use feed additives to promote nutrient absorption and gut health development. Such products may include acidifiers, prebiotics, and exogenous enzymes. But definitely consult with your nutritionist before making any changes.”

Feeder hygiene and dispensing mechanisms are also important. Producers must ensure feed is fresh and not caked onto the feeder, Huber says. Increasing the frequency of feed delivery can also help stimulate intake.

In addition, “make sure feeder pan coverage is approximately 50 per cent,” Huber says.

“You don’t want the feeder pan to be overflowing because the excess feed could build up in the corners, but you also don’t want the feeder to be too scarce because you want feed to be present when the pigs go looking for it.”

More feeder space for each pig could help smaller and quieter pigs access feed without getting bullied out of the way, Blackwell’s research team recently found.

“An inch and a half to two inches (3.8 to 5.0 centimetres) of feeder space per pig will ensure they do not have restricted feed intake,” Blackwell says.

“One inch (2.5 cm) per pig may be adequate for the first two or three weeks after weaning, but for the next three or four weeks, when the pigs put on more weight, more feeder space is better. Adding another 50 per cent of feeder space costs between $0.05 and $0.10 per pig over the lifetime of the feeder. You easily get that back in added weight – particularly for the quieter and less aggressive pigs who don’t want to push their way in.”

Another strategy producers can use to reduce post-weaning lag growth and feed costs is to take advantage of compensatory growth, a recent study showed. “Healthy pigs can exhibit compensatory growth after a period of feeding them a less digestible diet, such as a corn- or soybean-based ration, instead of a diet with lots of animal protein,” Huber says.

“Their growth will slow down early in the nursery but then their growth accelerates, and they can achieve the same exit weight as piglets fed a conventional nursery diet. This approach can be a way to reduce feed costs in the nursery, too.”

Overcome nursery challenges

Hog producers can use technology and work with their teams to address issues and promote pig performance in nurseries.

“Always have an accurate data recording system and room monitoring datasheets that provide information on the number of pigs in the nursery, date of entry, age of animals, treatment provisions, mortality and incidence of disease,” Robles says.

Producers can also collect information on out-of-feed-or-water events, storms and power outages that pertain to each batch of pigs, he says.

Measure “entry weights of every batch of pigs. Have another weigh-in at the mid-nursery stage to know if they are growing according to the growth curves you expect and project.

“Your veterinarian, feed nutritionist or production specialist can help you understand reasons why the animals may not be growing as projected.

“On exit, knowing how the group performed throughout the nursery can help you compare and improve on subsequent batches you bring into the barn,” Robles says.

Indeed, nursery management is like a “Jenga puzzle. Every time you miss feedback, feed intake, or temperatures in the barns, for example, a block comes out of that Jenga tower,” Bruner says.

“It is crucial to make sure all the pieces are stacked properly” throughout this production stage.

As a result, perhaps the most important piece in the nursery production puzzle is to “maximize feed intake in those first two to three days after young pigs enter the nursery,” Blackwell says.

Overall, “every barn has its own set of challenges,” Robles says.

“But the universal truth about having great biosecurity to prevent entry of diseases, sourcing animals from a high-health-status herd and following herd veterinary guidelines are the main focus areas to work on” to mitigate challenges and promote optimal animal performance, Robles says.

 

View this article in Better Pork, February 2021.

 

 

 

 

Maintain mycoplasma-negative herds with laryngeal swab tests from incoming gilts

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Sow farms that have eradicated Mycoplasma hyopneumoniae (M. hyo) must continue surveillance to keep the pathogen out or the results will be devastating, according to Laura Bruner, DVM, Swine Vet Center (SVC), St. Peter, MN.

“The most common entry is usually gilt introduction,” she said. “Mycoplasma can enter through the air but is less frequent.”

Right test for surveillance

Historically, serology tests were used to see if the incoming gilts were negative to M. hyo. But those tests are six weeks behind the infection, Bruner claims.

“In serology, we’re really looking at antibodies,” she explained. “Mycoplasma is a little bit unique in that we don’t start seeing antibodies in the serum until somewhere 4 to 6 weeks post-infection so I’m going to miss a really acute infection or a recent infection.”

Now she uses laryngeal swabs and M. hyo PCR (polymerase chain reaction) test to look for the actual bacteria in gilts. Bruner’s SVC colleague Alyssa Betlach, DVM, made this determination after conducting research to find the most accurate test and protocol for finding M. hyo in gilts.

“The laryngeal swabs tested for mycoplasma with PCR means we’re actually looking for the bacteria versus the response (to the bacteria) like serology does,” Bruner said.

Sampling techniques

The laryngeal swab requires a speculum to open the mouth and take a saliva sample from the larynx where saliva builds up. Bruner uses a regular spoon with an extension to collect the sample.

“We’re going closer to the respiratory tract and pulling out saliva that we can test for the bacteria,” Bruner said. “Ropes have been used in the past for mycoplasma, but the sensitivity is not very good… It does not pick up infections as well as laryngeal swabs.”

When a group of gilts comes into a facility, Bruner tests 30 animals and pools the tests into groups of three for a total of ten PCR tests.

The results?

Since implementing the test a year ago, she’s encountered a few suspects, but none positive to M. hyo. When she has a suspect test result, she goes back a week later and takes 60 samples, either laryngeal swabs or deep tracheal samples.

Testing for mycoplasma is not limited to gilts. “If we hear coughing on the sow farm, that will prompt us to test for mycoplasma, using the same method of the laryngeal swabs,” Bruner said. The same goes for early- or mid-finishing pigs. If a test is positive, she will go back to the sow farm and do more testing.

Bruner and her colleagues have conducted mycoplasma eradication on nearly 200,000 sows with an 80% success rate. These new surveillance protocols will help keep the successful herds negative.

 

The changing face of PCV: Virus experts compare notes on evolving pathogen in US swine herds

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Clinical disease due to porcine circovirus type 2 (PCV2) has been dramatically reduced thanks to vaccination, but concern remains about the persistence of PCV2 subclinical infection, even in vaccinates, and the virus’s propensity for change.

Furthermore, PCV3, a newly identified porcine circovirus that is genetically different from PCV2, is believed to be widespread in US herds and, so far, there’s no consistent evidence it causes disease.

Darin Madson, DVM, PhD

Those were among the observations shared by SVC’s Laura Bruner, DVM, and academicians, scientists diagnosticians at “The Changing Face of PCV,” a roundtable held at the 2018 Leman Swine Conference.

The panel agreed that new genotypes of PCV2 are expected to emerge, although currently the predominant genotype circulating in US herds is PCV2d, according to Darin Madson, DVM, PhD, Iowa State University, a leading PCV expert who tracks the virus’s evolution.

He explained that PCV2 replicates at a high rate for a DNA virus. PCV2a and PCV2b were major players in the US from 2005 until 2012, when a genetic shift to PCV2d occurred. Additional genotypes that have been identified include PCV2e and PCV2f.

‘Pretty unique’

“It’s pretty unique to have a DNA virus mutate to the level [PCV2] has,” Madson said.

Albert Rovira, DVM, PhD

Albert Rovira, DVM, PhD, a diagnostician at the University of Minnesota, said sequencing of PCV2 field strains in 2017 showed that more than 50% were PCV2d.

“What’s interesting is that about 35% were PCV2a, about 12% were PCV2b and about 3% were PCV2e. So, PCV2d is definitely the main genotype, but PCV2a and PCV2b are not gone; they are still there,” he said.

The pattern in Europe has been similar, said Joaquim Segalés, DVM, PhD, of the Universitat Autònoma de Barcelona, another PCV authority. There were big outbreaks of systemic disease that occurred with the shift in genotype from PCV2a to PCV2b around 2000 to 2001, and now it appears PCV2d is increasing in prevalence.

‘Success story’ but…

Despite the shift in the predominant genotype of PCV2, panel moderator and practitioner Clayton Johnson, DVM, Carthage Veterinary Service, said, “Vaccination against PCV2 has been a success story in the industry…but we always ask if things could be better. Subclinical PCV2 disease remains a problem.”

Joaquim Segalés, DVM, PhD

SVC’s Laura Bruner, DVM, of the Swine Vet Center (SVC), said, “Subclinical PCV2 disease is super hard to find…I wasn’t worried about it before, but I think that’s probably what concerns me the most now…PCV2 wasn’t a big deal at first, then all of a sudden it became a really big deal. I don’t want to [go] back there,” she said.

Similar concern was voiced by Vitelio Utrera, DVM, PhD, a swine respiratory disease specialist with Zoetis, who said subclinical infection may be underestimated. “If the vaccines are working well, that brings the genetic shift into question. If there’s no immune pressure, why is the virus genetically changing?”

He referred to a study in herds with no clinical PCV2 disease that had improved average daily gain and growth performance after PCV2 vaccination. “So, in that way, they showed there was a subclinical infection associated with PCV2.”

‘Incomplete’ cross-protection

Segalés believes current vaccines are controlling subclinical infection and said there’s no need to update vaccines.

However, Meggan Bandrick, DVM, PhD, a Zoetis scientist, said cross-protection is not complete. If heterologous vaccine strains are used — vaccines that aren’t matched to field strains — “we see [more] viremia and fecal shedding” compared to the use of vaccines that match field strains.

“So, you may still see protection against disease where the vaccine and challenge strain are mismatched, but that subclinical disease is still there.”

Clayton Johnson, DVM

As genetic shifts occur, there’s a growing gap between vaccine and field strains, Bandrick maintained. That gap, substantiated with results from epitope analysis, is what prompted Zoetis to develop the first PCV2 vaccine with two genotypes — PCV2a as well as PCV2b. The vaccine is also effective against PCV2d and is expected to provide broader coverage against current and emerging genotypes of PCV2.

Vaccine versus vaccination failure

Several panelists said an important key to successful PCV2 control is proper use of available vaccines.

Segalés acknowledged that vaccination isn’t perfect, “especially if we use a single shot. Try two doses and you will improve results from vaccination, for sure.”

Madson added, “I’m not sure I can singly point to vaccine failure. There’s vaccination failure. There’s a difference.”

Similar experience was cited by Rovira, who said he hadn’t dealt with any cases he thought were real vaccine failures.

Laura Bruner, DVM

“We know that in most cases the vaccines work really well, if we use them well,” but he cautioned about cutting corners at times when the swine industry isn’t as profitable. “When we tried to cut corners on PCV2 vaccination, we started seeing it again.”

SVC’s Bruner said, “Everything starts with the sow herd. If you have a really good PCV2 vaccination program on your sow farm, those instances of vaccine failure or vaccination failure are less just because you started with a lower amount of PCV2 on the sow farm being transmitted to piglets.”

More PCV3 circulating

Panelists emphasized that PCV3 and PCV2 are different viruses. PCV3 appears to be widespread but went largely undetected until recently, they said.

Rovira said there are reports of PCV3 as far back as 1996 in Spain, and in Sweden, PCV3 was found later in a sample collected in 1993. “I think we would all agree this is a virus that has been among us for a long time.”

Vitelio Utrera, DVM, PhD

Jianfa Bai, PhD, a molecular diagnostician at Kansas State University, said in his lab, the PCV3-positive rate has gone up, indicating a close eye should be kept on prevalence changes in the field.

Nevertheless, Bai, as well as Segalés, Madson and Utrera, said that so far, PCV3 is merely a finding and proof is lacking that this virus causes disease. Johnson added, “…it’s the classic question of infection versus disease. I have absolutely found infection. I have not yet found anything I would characterize as a disease…”

Bruner, however, expressed concern about PCV3 and said she’s finding a lot in all types of tissue and in processing fluids. She described a case she had involving a sow herd with a high mummy rate. Lab testing showed high levels of PCV3 in mummy tissue as well as epicarditis and myocarditis. Other pathogens were not found.

‘Very common’

Meggan Bandrick, DVM, PhD

Madson said PCV3 is often seen at the Iowa State Diagnostic Lab, and although it’s been found in higher quantities in reproductive cases testing negative for other pathogens, the causative pathogen may have cleared by the time samples were submitted.

Rovira said his lab is likewise finding PCV3 to be “very common,” now in over 34% of samples that come through. There have been a few myocarditis cases associated with PCV3 from different farms and different clients. “That builds confidence for us that the first reported case was not just a fluke.”

In some of the cases, there was an influx of gilts. It could be that PCV3 is subclinical and does nothing, but if an imbalance of immunity occurs in the herd, problems may occur and then resolve. His overall impression about PCV3 is that it can be relevant in a very small percentage of cases.

PCV3 can also occur along with other pathogens, such as PCV2, reproductive and respiratory disease virus and parvovirus, panelists reported.

PCV3 vaccine?

Because PCV3 and PCV2 are less than 40% genetically similar, Bandrick and others said PCV2 vaccines would not cross-protect against PCV3. That brought up the question of whether a vaccine for PCV3 is needed.

Bandrick said at this time, a PCV3 vaccine would not be of great benefit to the industry, but she stressed the situation needs to be carefully monitored. So far, it’s not been possible to culture PCV3 in the lab, but there are other ways to develop a vaccine if one is needed.

Jianfa Bai, PhD

Bruner said if a PCV3 vaccine were available, she’d probably try it out when there’s a herd with a high mummy rate and the only pathogen that can be found is PCV3. Similarly, Rovira said he believes other practitioners would try a PCV3 vaccine for cases of abortions or mummies if they thought PCV3 was involved.

Despite all the questions that remain about the significance of PCV3, Segales said, “Certainly, PCV3 can be added into the pile of pathogens you are looking for…I would say let’s try to isolate it so we can perform experimental infections.”

Utrera agreed and said for now, “…we need to have the virus, we need to reproduce the [signs] and lesions, and we need to identify any associated cofactors and then record them.”

Editor’s note: For a copy of the roundtable proceedings booklet, click here.