|
John Gadd
As you in Canada have discovered some time before us, this PCV2 circovirus pig wasting disease is a real beast! With a head start on us, I accept that you may know more about it than we do, but two conversations I had in Alberta in January have suggested that the opinion "You can't do much about it" is as common over here as it is in Europe.
Personally I feel that there are several things you can do both to prevent its ingress and to mitigate the sometimes catastrophic effect should it get into your unit. Shall we try and pool our ideas?
Why is it so prevalent today ?
Many of the "new" viruses attacking our pig herds are virulent, often resistant to treatment and seem to be on the increase. This is probably due to 3 main reasons.
-
Low Grade Immunity: Farmers are still using "old" methods of establishing natural immunity in their sow herds which are insufficient to provide the sows, especially replacement gilts, with sufficient time to acquire natural immunity to these "new" viruses which can then be passed on as maternal protective antibodies to their litters.
In Europe, we've followed with interest the Canadian view that you can breed gilts successfully 3 weeks or more earlier than the 225 to 230 days (125-135 kg) age we recommend here. I admit we've looked askance at our earlier mating advice because some of our skilled breeders, if they get the nutrition of the gilt right and very carefully manage the lactating sow subsequently, have had no problems. But in contrast we find our "ordinary Joes" benefit from our much later breeding advice, especially in the area of longevity and lower culling rates - like 35% to 38% in place of 45% or more, especially in the second and third parities.
Now, along have come these viruses which seem to rejoice in over-hasty induction times, i.e. 3 weeks in place of 6 weeks or more.
Is PMWD a legacy of too-early breeding coupled to too rapid induction and a poorly-planned challenge program? Could be.
-
Using outdated (non-virus specific) disinfectants. These new viruses can be more difficult to kill with traditional disinfectants (lysol, formalin, sodium hydroxide) at traditional dilution levels. An approved oxidative disinfectant like Virkon at specific dilution levels is essential to get through the virus's own protective shield.
-
Not using a farm-specific detergent. The new viruses love organic matter, which gives them added protection against the virucidal effect of an oxidative disinfectant. Failure to remove all faecal and fatty caked-on detritus can allow these new viruses to survive on housing surfaces, equipment, boots and transporter vehicles. Thus a degreasing (farm-approved) detergent (like Biosolve) at the advised dilution and ëcover' recommendations is an essential prerequisite to the subsequent correct use of the right disinfectant.
It is because many farms have not updated their management in all three areas that diseases like PMWS, PDNS, PRRS, Swine 'Flu etc are gaining a hold on their farms.
Indeed, I'm going to be naughty and suggest that all these new diseases can be categorised with just one set of letters - TPFDs or 'Typical Pig Farm Diseases!'
|