Stochastic Model of PRRS Control Strategies on a US Swine Farm27 May 2016
This article looks at the effectiveness of different combinations of control strategies for PRRS at the individual herd level. The goal is to determine the most effective strategy for PRRS virus control
How is it done?
Stochastic models simulated PRRS outbreaks on a hypothetical small, medium, or large farrow-to-weaning swine farm in the Midwestern United States. Different control strategies were compared in the models: from none to 4 several combinations of immunization, herd closure, and gilt acclimatization. In addition, by combining 3 virulence status of PRRSv and 3 herd sizes, nine different models were simulated.
The goal in each simulation was to have negative PCR results on 3-week old piglets (PRRS stability).
What are the results?
Increasing PRRS virus virulence and herd size were negatively associated with the probability of achieving a stabilized status. Virulence level appeared to have a greater influence on the probability of the farm achieving a stabilized status than did herd size.
For the baseline scenario (no PRRS control strategies implemented), a stabilized status was achieved only in the model for small herd size and low PRRS virus virulence.
Repeated mass immunization with herd closure or gilt acclimatization was a better alternative than was single mass immunization for disease control within a farm.
What implications does this paper have?
For a farrow-to-weaning swine farm, with the goal to reach breeding herd stabilization the recommendation is to implement repeated mass vaccination with a PRRS MLV every 15 also, herd closure appeared to be more beneficial than only gilt acclimatization.
Article summarized by www.prrs.com