Using PRRSV-Resilient Sows Improve Performance in Endemic Infected Farms with Recurrent Outbreaks

Abstract

The selection of porcine reproductive and respiratory syndrome (PRRS) resilient sows has been proposed as a strategy to control this disease. A discrete event-based simulation model was developed to mimic the outcome of farms with resilient or susceptible sows suffering recurrent PRRSV outbreaks. Records of both phenotypes were registered in a PRRSV-positive farm of 1500 sows during three years. The information was split in the whole period of observation to include a PRRSV outbreak that lasted 24 weeks (endemic/epidemic or En/Ep) or only the endemic phase (En). Twenty simulations were modeled for each farm: Resilient/En, Resilient/En_Ep, Susceptible/En, and Susceptible/En_Ep during twelve years and analyzed for the productive performance and economic outcome, using reference values. The reproductive parameters were generally better for resilient than for susceptible sows in the PRRSV En/Ep scenario, and the contrary was observed in the endemic case. The piglet production cost was always lower for resilient than for susceptible sows but showed only significant differences in the PRRSV En/Ep scenario. Finally, the annual gross margin by sow is significantly better for resilient than for susceptible sows for the PRRSV endemic (12%) and endemic/epidemic scenarios (17%). Thus, the selection of PRRSV resilient sows is a profitable approach for producers to improve disease control.

Multiplex Assay to Determine Acute Phase Proteins in Modified Live PRRSV Vaccinated Pigs

“…Thus, pigs that do not raise a viremia (PCR-negative) after 21 DPV are classified as resilient, whereas those with PCR-positive results are considered susceptible to the infection. This classification has been shown useful, for instance, to predict the reproductive performance of sows undergoing PRRSV infection with positive economic effect when selected for . We hypothesized that resilient responses should be associated to low or moderate increases in positive APP such as haptoglobin, pig-MAP, C-reactive protein, and serum-amyloid A1 when compared to susceptible responses.…”

“…This classification has been shown useful, for instance, to predict the reproductive performance of sows undergoing PRRSV infection 17 with positive economic effect when selected for. 18 We hypothesized that resilient responses should be associated to low or moderate increases in positive APP such as haptoglobin, pig-MAP, C-reactive protein, and serum-amyloid A1 when compared to susceptible responses. The reverse would be expected for apolipoprotein A1, a negative APP.…”