Editor’s note: This is the last in a series of articles. Part 1 was published in the February 2006 issue. Part 2 was published in the March-April issue.

How do you troubleshoot gilt reproduction problems, such as low fertility or breeding challenges?

A panel of experts addressed these issues, among other things, during a roundtable discussion on “Optimizing gilt reproduction and development” held in St. Paul, Minn., prior to the 2005 University of Minnesota Allen D. Leman Swine Conference. Intervet sponsored the roundtable.


Experts agree that the first priority in troubleshooting gilt reproduction and development problems is getting on the farm and taking a first-hand look at the situation.

Indiana swine veterinarian Max Rodibaugh, DVM, moderated the discussion. Other participants included: Joe Connor, DVM, MS, swine veterinarian with Carthage Veterinary Services, Carthage, Ill.; George Foxcroft, PhD, swine reproductive physiologist, University of Alberta, Canada; Roy Kirkwood, DVM, PhD, swine reproductive expert, Michigan State University; and Robert Knox, PhD, applied swine reproductive physiologist with the University of Illinois

“We drag out our real-time ultrasound equipment,” says Knox. “We usually look at a percentage of the gilt populations. We’ll scan a percentage of the animals (in various weight ranges from 180 pounds to 240 pounds) that have either expressed or not expressed estrus.

“We’ll find out what percentage from random selected animals in each range have corpora lutea. And then we try to find out do those animals have an estrus associated with that? Then we’ll go from there. We’re looking at quality of the estrus detection or trying to determine if there is a problem in these gilts expressing pubertal estrus.”

Knox adds that “when there have been problem groups, we’ve also suggested that clients try to find out what their PG 600 response is, so that in any of those particular groups that we may measure within a window of time, you can take a percentage of animals and find out which will express estrus in response to this hormone injection within a five-day period of time.”

Boar exposure
Boar exposure also is something to look at, says Knox. “How often and under what circumstances is physical contact or fence line contact being used?”

Kirkwood agrees that you need to look at gilts’ puberty-stimulation status and their estrus-stimulation management.

“We try to troubleshoot very quickly through the obvious things,” says Illinois swine veterinarian Connor.


Boar exposure is something to look at when troubleshooting gilt problems.

“If records are available, you can determine very quickly if they have the growth and weight targets by looking at slaughter dates,” he says.

Health history
“We also review health history. The genotypes we work with historically cycle very well, so it’s usually a breakdown or a failure in the system. We really think we’ve got to get in the barn and actually heat check with the staff.

“So for us, the real troubleshooting is just getting out there and actually working with them and at the same time getting off the list those things that they would like to blame it on as quickly as possible.”

Connor adds that one of the big challenges is keeping the people who work on the farm understanding what should happen week-to-week. “For us, a key challenge is getting them to understand that we expect a certain percentage to be in estrus this week, and if they’re not in estrus, what’s the next step, rather than waiting for weeks three and four where they accumulate, and then they’ve got a backlog in the system again.”

Kirkwood agrees that the first priority is to visit the farm. “Go and see what they’re doing.”


Illinois swine veterinarian Joe Connor says he tries to troubleshoot gilt problems with clients as quickly as possible.

Canadian expert Foxcroft says: “Our most effective approach nowadays is to get the management to come up to our SwineResearch & TechnologyCenter in Edmonton, because that’s where it usually starts.

“We have a session with the key management people and agree on the key drivers that we will focus on, and the research that supports different implementation programs. A lot of the time you’re working with a unique problem, but in fact the management is not supportive of the protocols adopted, or management doesn’t fully understand the recommendations. We’re tending to take a top-down approach now, and I think we can deliver a fairly comprehensive workshop on gilt development.”

Down to basics
Foxcroft emphasizes that you really have to get down to the basics and get all these things on the table at the start. “There has to be concerted buy-in from the whole system, starting from the very top, if a breeding management program has any chance to succeed.

“Ideally, management should involve thegenetics company. Sometimes they’re aleady working as technical support within the production system, and sometimes they’re not.


Veterinarians and producers need to take a more proactive approach in interventions for improving gilt reproduction and development challenges, says Indiana swine veterinarian Max Rodibaugh.

“However, in our experience it’s fairly useless if you’re talking about troubleshooting gilt development problems, if whoever represents the source of the gilts is not involved.”

Once you get everyone on the same page, Foxcroft says, then you go on to various potential interventions to try and keep the flow of eligible gilts within the design constraints of the gilt development unit. These interventions might include initial boar contact, remixing non-cyclic gilts and the use of PG 600 to produce a flow of opportunity gilts as needed.

Gilt health issues
Roundtable participants also discussed some of the important health-related issues related to gilt development, including vaccination strategies they use to help prevent and control specific health related issues in gilts.

“What we’ve learned over the years is that we want to have the vaccinations or exposure complete before puberty for the general health challenges such as Mycoplasma, PRRS or SIV,” says Connor. “Of course parvo is delayed until later to avoid maternal antibody interference. We’ll always set up our strategies to have that gilt acclimated very early in her life.


Michigan StateUniversity swine reproductive expert Roy Kirkwood believes that more intensive training may be the key in improving gilt reproduction and development.

“We think time is important and it is very herd specific. Some of the herds are going to acclimate for PRRS and a number of the herds will not. We also have to figure out the sequence to do that. Natural exposure may not be enough. Sometimes there is too severe of a health challenge. It’s difficult to get all of that balanced and end up with a healthy gilt that’s growing well to hit targets.”

Connor adds that “we still do a lot of feedback for natural acclimatization. That tends to be in the late developer phase rather than early, unless we’re trying to do exposure because of PRRS. Herds still feedback pre-farrowing and pre-breeding. With breed-to-wean units, common parvo circulates through those herds even though they have been vaccinated.”

Connor says that vaccination protocols would include two parvo/lepto/erysipelas, administered when gilts reach 27 weeks for the first vaccination and 29 to 30 weeks for the second. “There’s probably still a little bit of risk there on maternal antibody interference.”


Boar exposure also is something to look at when troubleshooting gilt reproductive and development challenges, says University of Illinois swine expert Robert Knox.

Connor also says that Ileitis (Lawsonia) is usually handled through one of two strategies. “One is to vaccinate gilts usually at eight to 10 weeks of age. The other is a pulse medication program where we would medicate for two weeks, then no medication for two weeks, and then back on for two weeks. Since most gilt developers have more than one age of gilts, we tend to vaccinate for Lawsonia because of the ease of getting that done correctly versus a pulse program.”

Knox says gilts that move from a standard finishing unit into a gilt development unit or breeding facility may sometimes have digestive problems as they transition from a grow-finish type feed to gestation feed.

“We’ve implemented, at least in a test situation, some antibiotics before they come over. We’re also considering the idea of transitioning them into a gestation diet.”

Knox acknowledges that the herds he deals with “are probably not in the highest health status compared to some of the other facilities out there, so in our scenario, we need to consider better transitioning because our health is not as high. We need to have a better entry program. There are some digestive diseases that may arise when we transition them abruptly.”

Gilt development: There’s still room to be better

Swine veterinarians and swine reproductive experts who participated in a roundtable discussion on optimizing gilt reproduction and development generally concluded that there is still much room for improvement in gilt management and productivity.

“There’s a lot of potential improvement to be had,” says Indiana swine veterinarian Max Rodibaugh.

Among other things, he says: “We need to be more attuned to the lifetime production of our females.”

Further, veterinarians and producers need to take a more proactive approach in interventions, according to Rodibaugh.

“We need to be prepared with interventions, rather than react to problems. If we have those interventions in place, then we’re not as likely to make poor judgments when problems arise.”

Canadian swine reproductive expert George Foxcroft believes that improved staff training and better management leadership could go a long way toward improving efficiencies in gilt reproduction and development. “The staff must be trained and the managers must lead by example.”

Michigan StateUniversity swine reproductive expert Roy Kirkwood believes that more intensive training may be the key. “It maybe comes down to training,” he says. “We know what to do, but we don’t always do it.”

Illinois swine veterinarian Joe Connor believes there is plenty of knowledge available to help make improvements. “We have a lot of science, but to set the programs up, it comes down to implementation and consistency of implementation,” says Connor. “There are some tools, including pharmaceutical products, that can help us to do that. These may need to be looked at more closely.”

University of Illinois expert Robert Knox believes that one simple thing that can be done is to prevent overcrowding of animals.

“One of the things that sticks in my mind is to prevent crowding,” says Knox. Even if things back up, stick with your plan. Don’t crowd gilts in order to compensate. It just snowballs.”