It is logical while most biosecurity focuses intensely on breeding herd facilities, but a group of Iowa State University researchers are studying growing-pig site biosecurity gaps following porcine reproductive and respiratory syndrome (PRRS), porcine epidemic diarrhea (PED) and porcine deltacoronavirus (PDCoV) infections and investigating a regional Actinobacillus pleuropneumoniae (APP) outbreak
More analysis of the data containing red flags is ongoing, but Derald Holtkamp, who is leading the study, says, “If we ever get ASF or another foreign animal disease in the U.S., and we don’t detect it very, very early, it’s going to spread because of a lack of ability to prevent transmission from one herd to another.”
Of the 75 groups of pigs followed from nursery to marketing in the first study, only two stayed negative for PRRS virus. All were negative for PRRS virus and coronaviruses at placement, SHIC reports.
Interesting Patterns
There are some interesting patterns in the data, Holtkamp says. One thing in particular stands out: how closely correlated the frequency of events (movements, deliveries, maintenance, etc.) are with positive tests for PRRS virus, PED virus, and PDCoV, in both the nursery and finishing phase.
PRRS virus outbreaks occurred primarily in the finishing phase after movement, but coronavirus (ie., PED virus) positive tests were more frequent in the nursery stage. Transmissible gastroenteritis (TGE) was never detected in any of the groups, researchers point out.
Find the Industry Summary of the report at https://www.swinehealth.org/results/ and search for 20-073.
“The larger number of events in bigger groups of pigs, the more likely they were to go positive,” Holtkamp said in a SHIC release.
Livestock Transportation Needs More Diligence
An initial review of results points to livestock transportation as an area needing more diligence.
“The timing of the breaks in the finisher phase for PRRSV were frequently associated with the timing of pig movement events from the nursery to finishing phase sites,” Holtkamp said.
Other analysis surrounding four groups of pigs known to be negative from the sow farm then tested positive very early points to the nursery barns where they were placed, SHIC reports. Previous groups in those barns had tested positive – four for PED virus and three for PDCoV. Researchers noted the pigs picked up the viruses either via transport or in facilities not properly washed and disinfected.
APP Outbreak Study Identifies Biosecurity Gaps
As this study was taking place, an outbreak of APP was identified in a 400-square mile area of central Iowa from late 2021 through early 2022, SHIC reports. Holtkamp leads a team that is currently investigating the spread.
“This was a unique situation when from November through April, the only positive cases for APP serotype 15 were diagnosed in a very small geographic area,” Holtkamp said in a SHIC release.
Further investigation of seven individual groups of pigs affected by the outbreak indicate rendering was likely involved in transmitting the bacteria to several of the groups. In one circumstance, a caretaker removed carcasses from one APP-positive site and later visited another site on the same day without changing boots and coveralls, which then subsequently broke with the bacteria.
More information on the APP investigation will be made available as the study is completed. Both the growing pig biosecurity study as well as the APP investigation provide clear results pointing to the need for better growing pig facility biosecurity, SHIC notes.
“If an FAD is found in this country, we can’t wait until after that to figure out how to do rendering more safely,” Holtkamp said in a SHIC release. “These are red flags telling us we must be prepared so we don’t spread an FAD all over before we realize it.”
More from Farm Journal’s PORK:
PRRS, PED and Biosecurity: What Can Producers Do When Diseases Strike?
A New Approach to Biosecurity in Swine Systems
