When a farm is hit by an outbreak of porcine epidemic diarrhea virus (PEDV), it can take months for production to return to regular levels. Dr. Matthew Turner, a veterinarian with Prestage Farms, discussed the difficulties pig producers have rebounding after a PEDV outbreak during a remote PEDV roundtable discussion hosted by WATT Global Media during the VIV International Pork Production Summit. The summit was held in conjunction with the International Production and Processing Expo (IPPE) in Atlanta on January 29.
PEDV is a similar virus to a more well-known porcine virus, transmissible gastroenteritis virus (TGE). The methods used to treat and disinfect after an infection of the two viruses are also similar. However, the recovery process is far from similar, Turner said.
Historically, it has been relatively easy to get rid of TGEV, Turner said, and the odds of TGEV becoming endemic is rare. Conversely, it is difficult to get rid of PEDV and the odds of it becoming endemic is much more common. The showing of clinical signs during a TGEV recovery is rare, but it is common with PEDV, he added.
In a recent sampling of data obtained from 33 pig farms, it took an average of 14 weeks after a PEDV infection for the number of pigs weaned to return to normal production numbers. The sampling showed sows weaned about 10 piglets two weeks prior to a PEDV infection, but that number dropped to almost none the week of the infection. During the following three weeks, there were no pigs weaned, and it wasn't until the sixth week before weaning levels reached 60 percent of where they were before the PEDV infection.
"It takes about 14 weeks of production after the outbreak before a sow actually starts to wean the number of pigs she should be weaning," said Turner.
While weaning numbers may rebound around the time of the 14 th week after a PEDV infection, it actually takes even longer than that for production to fully recover. "We really don't ever come back to normal production through the full term for a sow farm," said Turner.
Producers are more vigilant after a PEDV outbreak, and abortions and reduced conception rates are more common. An aggressive quality control effort is made to make sure that farms that have experienced a PEDV outbreak don't spread the virus between litters, and they do not do any fostering.
"Those all add up to higher losses pre-wean losses than we normally would expect to see," Turner said.
