PRRS – Swine in Minnesota

Yearly incidence rate of PRRS per MSHMP Participating Production System

This week, the MSHMP team is sharing the yearly PRRS incidence rates in the 39 participating systems.

Keypoints

The average incidence rate for all systems during the entire period described was 0.27 PRRS outbreaks per farm per year.
The incidence rate of PRRS outbreaks within a system varies across years with some participants continuing to have lower incidences.

Understanding whether PRRS viruses in a neighborhood are closely related

This week, the MSHMP team is sharing results from a study looking at how related PRRSv ORF5 sequences from a same area are.

Key Points

28 space-time clustering of PRRSv based on producers’ routine molecular surveillance were identified in the course of 2010-2019.
Being inside or outside a space-time cluster significantly explains the genetic variability of most, but not all cases.
Assessing space, time, and genetic relatedness relationships in PRRSV transmission is complex, and overall trends might miss important case information.

Development of an automated model to capture and analyze whole-herd parameters associated with wean-to-finish mortality

This week, Dr. Linhares’s team from Iowa State University is proposing a model to analyze wean-to-finish mortality based on whole-herd parameters such as farrowing rate, PRRS status or even management factors.

Key Points

An automated model was developed to consolidate multiple data streams from weaning cohorts to their respective closeouts.
Sow farm productivity and health are highly associated with wean to finish mortality.
Sow farm-related data explained 74.1% of the variation observed on wean to finish mortality.

Best of Leman 2019 #3: Three systems views on PRRS decreasing incidence

A few days ago, we shared a report that PRRS incidence decreased in naive breed-to-wean farms. Interesting questions were brought forward by our readers so this month, we are sharing three practitioners’ experiences with PRRS in their systems: Dr. Tara Donova with the Hanor company, Dr. Jay Miller with The Maschhoffs, and Dr. Pete Thomas from Iowa Select Farms.

Comparison of PRRS incidence rate in status IV breeding herds during 2009-2019

This post is from the MSHMP team looking at status IV farms and their PRRS incidence between the years 2009 and 2019. Quick reminder, in 2011, Holtkamp et al. defined status IV farms as PRRS-negative per their shedding and exposure status.

Key points

PRRS incidence rate in status IV farms varied significantly from 2009 to 2019.
The incidence rate in status IV farms during 2019 was one of the lowest on record and comparable to the one observed in 2013 and 2014; the years of the PED epidemic in the US.
PRRS incidence in status IV farms during 2019 was significantly lower than the one of 2015 and 2016 and marginally non-significant lower (p=0.07) than the one of 2018.