It would be best to investigate the time of LVI (live virus exposure) in sow farms, the sows' Shedding time, and how many pigs go to wean to finish and spread the virus (low biosecurity). Then, those viruses would get back to the sow farms. If you have that information on the flow and location of the LVI sow farms and follow the sequence, you will find many answers and reasons why we should not use LVI.
It would be best to investigate the time of LVI (live virus exposure) in sow farms, the sows' Shedding time, and how many pigs go to wean to finish and spread the virus (low biosecurity). Then, those viruses would get back to the sow farms.
If you have that information on the flow and location of the LVI sow farms and follow the sequence, you will find many answers and reasons why we should not use LVI.