Since 2004, U.S. pork production has seen a steady increase in sow mortality, now hovering around a 12% average, according to the latest Pork Industry Productivity Benchmark Report released by MetaFarms. To lower that rate, Iowa State University researchers set out to see if identifying at risk sows and aggressively treating could have an impact on mortality.
"So, identifying sows early, be that whether they're off feed, they're lame, treating them early and aggressively to try to keep them in the herd," says Justin Brown, assistant teaching professor in Veterinary Diagnostic and Production Animal Medicine at Iowa State University.
Brown, who also serves as an instructor with the Swine Medicine Education Center, presented the team's latest findings at the 2022 Iowa State Swine Day in Ames. In addition to identifying and treating sows, Brown says the research team wanted to find out the time requirement and additional labor cost to add these extra protocols daily as well as to see if the process could easily be transferred to farm staff to continue.
The team began their research on a 4,000-head sow farm in central Iowa. The farm had three breeding and gestation buildings where all sows were stalled. The sows were mash fed once per day in the morning through drop boxes.
The farm was porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae positive. When the team started the study, the farm had a 17% sow mortality average.
Further examining reasons for sow mortality, from January to October 2021, 30% were due to pelvic organ prolapse. Another third, or 34%, were lameness or downers. Finally, about a quarter were sudden deaths.
Training was conducted June 7- 18, 2021. No evaluation was conducted in farrowing, only in gestation.
"By not looking at farrowing, we're probably not going to impact the pelvic organ prolapses at this level. Most of that's going to occur in our farrowing houses. You might see some of them out in gestation, but a majority's going to occur in farrowing, so probably not going to impact there," Brown says. "But what we could impact potentially were these lameness and sudden deaths that were marked as reasons for the mortalities in that farm."
Identification and training were conducted by one ISU veterinarian and one gestation barn staff member, who walked the breeding and gestation barns as sows were being fed.
"One thing we learned, having somebody in front and behind really helps you with getting the animals up that are down already," Brown says. "They can be kind of stubborn to get up sometimes just by walking the alley, but also hard to see the back legs if you're standing in front of the stall. So having somebody behind, you can pick up on is it a hind limb lameness or is it a swollen hock."
Any females that weren't eating or up at the feeder were flagged by a hanging card and would then be assessed or treated later. Evaluations took 30 minutes per barn/room with the goal to finish identifying sows before they laid down post eating.
"She's pregnant, kind of tired from standing on her feet at that point, she just wants to lay back down," says Brown. "So, you've got to be pretty deliberate with going through, which is why we would just flag them, to come back later, get her up again, to do a more thorough evaluation."
Some behaviors observed during the identification and training period included toe tapping, where the sow couldn't get comfortable enough to put weight on both hind quarters and possibly indicating lameness as well as leaving feed remaining and choosing to lay down.
For follow-up examination and treatment, Brown says it comes down to what works best for farm staff. Some farms may treat during examination while others may choose to do later in the day while other tasks, such as breeding and heat checking, are completed. All treatments should follow farm protocols per symptoms.
Following a two-week evaluation, off feed was the primary clinical sign the ISU team observed. Thirty percent had two symptoms, being off feed as well as lame. Gilts were the primary parity identified as at risk.
After examining 23 weeks of data before and 23 weeks of data after training, the researchers found the farm went from 16.75% to 12.5% in annualized sow mortality, a 4.2% reduction. The farm staff proved the training was productive, as they were able to keep the lowered mortality rate.
What's a 4.25% quarter reduction in sow mortalities worth? Brown says based off of the opportunity costs of losing pregnant females, additional cull sow income, and having to bring in fewer replacement females, it equates to about $50 per sow.
"And if you work that out over wean pigs, you get about $2 per wean pig savings for this farm," Brown says.
For the time commitment, Brown says on average expect it to take two people two hours per day for at-risk identification.
"That can be done while walking the barn, sweeping, dropping feed, doing your barn checks," Brown says. "It's going to vary based on herd sizes though. Smaller farm you can get through quicker, larger farm is going to take longer to get through."
For follow-up treatments, expect one hour per day and ideally, Brown says it would be best if one worker was assigned that duty for consistency.
Since the study, the pork production system has started rolling out the two-person risk identification teams to the 40 other farms in their system. As a system, they were running around 19- 20% for sow mortality and by implementing early identification and treatment of at-risk sows they have significantly decreased sow mortality.
Since this was done in stall gestation, the next question the ISU team wanted to find out was if the same protocol could be replicated across barn types. In May 2022 the study was repeated in a pen gestation farm within the same system. The farm houses approximately 4,000 head with sows in stalls from breeding to about 45 days gestation, then in pens from 45 days gestation to farrowing.
While data is still being collected, Brown says the team has found some tips and tricks for conducting early identification of at-risk sows in group housing. Each farm is going to be different in the amount of time it takes. For example, the process took the team closer to three hours. They also found it worked better to use three to four person teams. One person on each side of the pen and one walking down the middle that can use livestock paint to mark at-risk cases.
Regardless of stall or pen housing systems, Brown says early detection and individual treatments, particularly in breeding and gestation, should be a critical component in sow management.
"By the time we treat them, it might be too late," Brown says. "We really need to be doing this every single day."
He suggests treating individual sow care like individual pig care, treating them as A pigs, not C pigs.
"If we treat them as an A sow, it's more likely to have an impact, hopefully to keep her in the herd and reduce that mortality," Brown says. "And it's easily implementable. Just flag off-feed sows while feeding, sweeping in the a.m., whenever it works, then come back and treat later when that's appropriate."
The 11th annual Iowa Swine Day was held June 30 at Iowa State University. More information on the conference and sponsors can be found here. Videos and presentation files for many of the plenary and concurrent sessions can be found on the Iowa Pork Industry Center YouTube channel.