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Eradication of Porcine Reproductive
and Respiratory Syndrome
At this time, elimination
of PRRS virus from infected farms is possible by 4 primary methods:
1.Whole herd-depopulation/repopulation
2.Test and removal
3.Herd closure and rollover
4.Production of negative pigs from positive sows
Advantages and disadvantages of each method are
as follows:
1.Whole herd depopulation repopulation
Advantages
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High degree of efficacy
Solves multiple disease problems at the same time
Results in genetic improvement
Vast experience of veterinary industry
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Disadvantages
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Costly
Requires multiple sites for off-site breeding of new clean stock
and finishing out of diseased pigs
Re-infection can occur during repopulation process
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2.Test and Removal
Advantages
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High degree of efficacy
Low risk, due to speed of the testing process
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Disadvantages
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Testing cost can be high if ELISA and PCR are used to test sera
Requires removal of exposed breeding animals
Feasible only in herds with low (<10%) seroprevalence in
breeding herd
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3.Herd closure and rollover
Advantages
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Initial efficacy appears promising
Does not require excessive testing or removal of breeding animals
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Disadvantages
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Requires off site breeding facilities
Requires a long time to complete
Relies on consistent natural exposure of all replacement gilts
and a lack of PRRSV transmission in the breeding herd over time
Questionable if this can be accomplished in all cases
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4.Production of negative pigs from positive sows
Advantages
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Preserves genetics
Can improve overall health status of offspring through the use
of medication or specific vaccinations
Improvements in health and performance of offspring can be significant
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Disadvantages
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Transmission of PRRSV from dam to offspring can result in production
of infected batches of weaners
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