Six years ago, after seeing anywhere from 8 to 12% wean-to-finish mortality on porcine reproductive and respiratory syndrome-negative pigs, Pillen Family Farms decided they needed to scale back, get back to the basics and dig into the root causes of what was happening. The pork production system, which is based out of Columbus, Nebraska, and markets around 2 million pigs per year, decided to remove everything, according to herd veterinarian Christine Mainquist-Whigham.
"We took all of our meds out, kind of just stripped it all down and said, 'all right, we're going to build it back up.' It took a lot of discipline, but we slowly added in different things to try and measure what our interventions did," Mainquist-Whigham said. "It also took a lot of discipline to do one change at a time. As you can expect, you pull all your meds out, you pull everything out, and you're where you're unhappy with 8 to 12% wean to finish mortality, now you're looking at 12 to 16% mortality, so it did take some patience on our end to do that.
During the birth to market livability session at the Allen D. Leman Swine Conference in St. Paul last month, Mainquist-Whigham told attendees the production system decided to focus on diet, sanitation, stressors and technology among other management areas to improve livability.
After pulling all of the medications and other complexities out of the diet, the first intervention was to change feed management. A plasma product was put back in the herd's diet, dramatically improving nursery liability, Mainquist-Whigham said.
"It was about a 2% mortality difference, just putting the plasma back in at that time," she said. "We also put in some antimicrobials, so we had some Mecadox. We then scaled that back to DEN/CTC and now today, we are able to go naked in all of our nursery and finishing diets."
Sanitation was the next intervention Pillen Family Farms addressed.
"We were all in, all out, multiple flows coming in and a four-day turnaround on these nurseries and we realized maybe we weren't getting them as clean as we thought," Mainquist-Whigham said. "We've got hot power wash and a disinfectant, but it just wasn't getting the job done. These are brand new nurseries built within the last five years, plastic floors, state of the art and still seeing reduced performance."
The pork production system decided to implement a new sanitation protocol, adding a detergent step that had not been deployed previously. They looked at several different types of detergents and finally settled on an alkaline product.
"Our sanitation protocol is to remove organic material, apply our detergent. We use a foaming tip and a one to 64 ratio. Let it sit for 20, 30 minutes, come in with a hot power wash, inspect, disinfect. We use, reuse and synergize. Drying downtime might be 12 hours, 24 hours, so we do bake the rooms," she said.
Field data showed promising results. The production system tested Biokleen or Biosolve detergent on 340 barns total with more than 420,000 pigs. While it was about a $0.03 per pig investment, Mainquist-Whigham noted there was a dramatic decrease in mortality.
"So, where we were at 4.4% mortality without the detergent, we dropped down to a 3.2-3.3% mortality with the detergent. So, over 1% decrease in mortality, and all we did was that barn sanitation game," Mainquist-Whigham said. "The biggest difference there is the rotavirus disappeared. When we were starting pigs that first seven to 10 days, we're dealing with rota A, B, C. It was like a light switch overnight, no more rotavirus and still to this day, not dealing with any virus in our nurseries."
The next intervention was to try to eliminate stressors impacting pigs in the nursery. The pork production system’s existing vaccination program at that time was to go in mid-nursery, leaving many pigs depressed, off feed and sometimes an E. coli or parasuis break would follow.
Instead, they decided to get all the vaccinations done while pigs are on the sow, still comfortable and not stressed. They provided a processing vaccination for pigs already picked up at and then a vaccination 24 hours prior to weaning.
"Not only did we do all this before they were stressed with that weaning event, but we also reduced one injection, so we're not having to go back in mid-nursery and give this second shot," said Mainquist-Whigham.
To test out the new protocol, Pillen Family Farms put 328 barns on trial, 187 of them with the late vaccination and 141 with the early vaccination. Prior to the trial, the veterinarian said the system was at a 3.2% to 4% mortality rate, with the traditional vaccinations at three and six weeks.
"The only change we made was the early pig vaccination, and we dropped to a 2.51%, so that was three quarters of a percent decrease in mortality just by switching that," Mainquist-Whigham said. "Now we did do a lot of work on maternal antibodies ahead of time, just to make sure that this was an okay program for us, but we've been doing this now since 2017, no circovirus breakthroughs, no ileitis breakthroughs in finishing and value added, along with the feed conversion benefits that we saw, was about 55 cents a pig."
The pork production system was also giving a PRRS vaccine on arrival in the nursery and within the first seven days they would see the exact same symptoms with pigs stressed, not eating, etc. After removing this vaccination protocol, mortality went from 2.6% mortality to 2.08% mortality just by not giving that early nursery vaccine. The savings from not having that mortality and from not giving that vaccine was about $0.67 per pig, Mainquist-Whigham noted.
After eliminating all medications from the system, including sow farms, the veterinarian said the herd started to have issues with mycoplasma suis and agalactia, which then led to high variability in wean weights and issues starting on feed correctly. They decided to try Pulmotil AC and administered it through the water continuously through lactation. In addition to sow benefits and fewer sow treats, the team also observed a nursery benefit from administering it.
"The striking difference would be dead and pull percentage, over a percent difference in mortality just by running this at the sow farm," Mainquist-Whigham said. "We're trying to be conscious about our antibiotic use and be responsible. We wanted to measure treatment, so we did also drop our treatments per pig in the nursery, just by running this in lactation. There was a wean weight benefit too, so it was hard to tease out whether or not it was the drug or the wean weight, but there was definitely a benefit there."
Another intervention Pillen Family Farms implemented was the installation of cameras in every single room in the nurseries. By being able to view pigs 24 hours per day, the pork production system realized some of the barns were not ventilated properly.
"These are brand new nurseries, and you think everything would be fine, everything's set up correctly, but inlets were in different places, feed lines are in different places, water lines, so it just wasn't consistent to start with," Mainquist-Whigham said.
After further examining inlets, the pork production system found it was drafting pigs in some barns. It was higher humidity, so the pigs were wet, and then heaters would kick on and cold air would be drafting the pigs.
While every barn is different, and needs tweaks to meet all the different settings, Mainquist-Whigham said in this case there was a lot of air dropping down the middle of thebi-fold inlets. They went through and bubble wrapped all of those. Also, the front pens were getting drafted more than the back pens, so weather stripping was added along doors. On really windy days, the attics were getting so pressurized that air was being forced into these nurseries, so some holes were cut in the side of the new barns and relief shutters were added, which Mainquist-Whigham said helped to release the pressure in the attic and no longer forced air through the inlets.
Another intervention was mat feeding, to get pigs up. One mat feeding field trial resulted with a one-pound heavier pig at day 14. In another study, looking at mortality with mat feeding in nursery barns, there was a 2.7% mortality with no mat feeding, while only a 1.9% mortality with mat feeding.
The veterinarian noted it is often said getting a pig started well in the nursery translates to a pretty easy finishing turn, but ear necrosis is one area the pork production system still needed to address.
"We'd get ear necrosis, a flu break in the nursery and two, three weeks later, fairly severe necrosis, maybe 80, 90% of the pigs affected by it," Mainquist-Whigham said. "Then you get into finishing, and we were finding doing postmortems, huge abscesses in the joints with trueperella pyogenes, and it felt like these ears are just sponges for trueperella and it's leading into this systemic issue.
The production system decided to implement an ear tipping protocol on day zero of birth. Because there's very little vasculature development, she said there's hardly any bleeding and the pigs don't seem to notice it. And the new protocol has almost eliminated ear necrosis from the system.
Finally, the last intervention the pork producer examined was stocking density.
"We looked at our stocking density over time and we've gotten tighter and tighter and tighter. I think that's natural, people want to maximize space, but we saw a direct correlation with our stocking density and our mortality," Mainquist-Whigham said. "Some barns where we're stocked at 6.6, 6.7 square feet, we're averaging 7% mortality and then our 7.5 square feet, we're down in that 5% mortality range."
They decided to look at this further and do a field study to examine two different densities, one at 6.7 square feet and one at 7.2 square feet. All barns were PRRS-infected at the time. The 6.7 square feet density had almost a 10% mortality rate, while the 7.2 square feet had an 8.3% mortality rate.
By taking everything out and implementing several interventions along the way, Mainquist-Whigham said the production system is much more judicious with antibiotics.
"In our PRRS-negative flows, our goal for 2022 is that 0.39 grams of antibiotic per pig marketed," she said. "Back in 2019, where we were still having to kind of cover with some feed medications, we were at 10.6, so our PRRS-positive flows are obviously not hitting this, but we are with PRRS negative, and that's our goal and that's our vision."