January 17, 2014
Impact of PED virus continues to threaten US swine industry
In 2013, an estimated three million pigs were lost due to porcine epidemic diarrhoea (PED) virus which continues to be a very critical health issue for the US swine industry.
The first cases were reported in May, and as of December 1, 2013, there were 1,512 cases in 20 states in the US. The disconcerting news is that this is an increase of 140 new locations from the week before, which is the largest one-week jump in cases. While South Dakota has only two reported cases, there are multiple cases in Iowa and Minnesota, and Nebraska just reported their first cases in the last two weeks.
Outbreaks of PED can be devastating. There is 100% mortality in new-born pigs, and this typically creates a five-week hole in pig flow because there are no pigs to wean. Pigs in the early nursery phase don''t experience the high death loss, but it does cause severe diarrhoea so many pigs are stunted and nursery performance suffers. As pigs get older and their own immune system becomes functional, there is little to no death loss, and most pigs experience just a one week lag in growth performance.
PED virus is not an airborne threat, however, it is very easily transmitted by manure, and if a virus-contaminated piece of manure were to be small enough to get aerosolised, then PED could travel in the air. The main way to prevent PED from getting on your farm, though, is to prevent any manure particles from shoes, trucks, trailers, semis, cars, et cetera from tracking onto your place. Unfortunately, PED is an extremely infective virus and it only takes a minute amount to cause an outbreak. PED can live in manure slurry up to 14 days at room temperature, but more than 28 days in cold slurry so it is not affected by the cold. It can also live in feed up to one week.
When pork producers take their pigs to market, the biggest threat of PEDv occurs as packing plants and buying stations are great commingling places for disease. Before getting out of the cab, producers need to put on a pair of disposal boots and then get the pigs unloaded. Before getting back into the cab when done, they need to take off and discard the boots immediately before entering the cab. Even a small chunk of manure on the floor mat means disaster. Many producers routinely go to truck washes after unloading hogs to clean out their trailer. While this is a good idea, truck washes are also another commingling place where PED is prevalent. Any manure that splashes up on the truck, tires, or boots during the cleaning process probably has the PED virus in it. After cleaning the trailer at a truck wash, it needs to be sprayed with a disinfectant and allowed to dry. Drying and disinfecting will take care of both porcine reproductive and respiratory syndrome (PRRS) and PED when done properly. Producers are encouraged to visit with the veterinarians on which are the most effective disinfectants. If a clean and disinfected truck and trailer can be dried at 160F for 10 minutes, the virus should be gone. If they are dried at room temperature, it''ll take one week to kill the virus.