Tag: MSHMP

Science page: Troubleshooting poor litter size using the National Swine Reproduction Guide

First, we would like wish you the happiest of holidays from all of us at the University of Minnesota, College of Veterinary Medicine.

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week we are sharing how to troubleshoot poor litter size within a production system using the National Swine Reproduction Guide, a report by Sarah Bloomer at North Carolina State University.

Key points:

  • The National Swine Reproduction Guide (NSRG; U.S. Pork Center of Excellence, Des Moines, IA) is a valuable tool to help producers utilize data analysis to troubleshoot reproductive problems in a herd or farm.
  • Analysis of farrow-to-wean farms within a North Carolina production system revealed extended wean-to-service interval of first-parity sows and poor performance of second-parity sows. NSRG recommendations include reviewing lactation diet composition and first-parity sow lactation feed intake.

Reproductive data from nine farms within one production system from 2011 to 2015 were obtained. Average Total Number Born (TNB) for the production system was 12.4 piglets born per litter, yet litter size was lowest in second-parity sows. Greater than 24% of second-parity sows failed to achieve the decision boundary criteria of 11.5 TNB. Within first-parity sows, 73% of the contemporary groups had greater than 10% of their sows failing to return to estrus within 10 days of weaning.

NSRG recommendations.gif

The following recommendations to improve TNB and reduce Weaning-to-Service Interval  (WSI) were created following consultation of the NSRG:

  1. Limit cross-fostering onto first-parity sows
  2. Review lactation diet composition, particularly amino acid content;
  3. Identify methods to promote first-parity sow lactation feed intake. If economically
    feasible, farms may also consider breeding sows displaying estrus 7 and 8 days post-weaning on their next cycle.

 

Science page: Investigating PRRS summer outbreaks in the US

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week we are sharing an investigation into PRRS summer outbreaks by Dr. Juan Sanhueza and the MSHMP team.

Key Points

  • Each year approximately 3% of the sow farms have a PRRS outbreak during the summer.
  • The incidence of summer PRRS breaks has been constant over the last 9 years.
  • There are geographical areas with higher or lower risk of summer breaks.
prevalence of summer PRRS outbreaks per year
Figure 1. PRRS summer outbreak incidence per year between 2009 and 2017.

A summer outbreak was defined as a PRRS case that happened between June 21st and September 21st of the year. The mean incidence of PRRS summer outbreaks was 3.2% between 2009 and 2017, ranging between 1.6% and 4.4%. The trend was stable among the years. (Figure 1) Not all areas are equal against summer outbreaks. Indeed, the region of Southern Minnesota – Northern Iowa is more at risk of outbreaks than others like Southern Iowa or Eastern North Carolina. (Figure 2)

areas with higer lower PRRS risk in the summer
Figure 2. Geographical areas with higher (red) and lower (blue) PRRSV incidence risk

Biosecurity measures against PRRSV should therefore be a concern all year round for swine producers!

 

Science Page: PRRS eradication efforts in Chile: Current situation and future prospects

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week we are sharing a report on PRRSV eradication efforts in Chile.

Key Points

  • After being introduced in 1999, PRRS was eradicated from the country in 2012.
  • In 2013 PRRS was again detected, sequence analysis suggested this was a new introduction to the country.
  • The Chilean swine industry and the Chilean Veterinary Services (SAG) expect to again eliminate the disease in the near future.

PRRS is a notifiable disease in Chile. It was first detected in 1999, and in 2000 both the swine industry and government joined efforts to eradicate the disease by a series of coordinated events including a mixture of herd closure and depopulation of infected premises. Vaccination was not allowed in the country to control PRRSV infection. The eradication program was completed in 2007 and as a result, Chile was declared PRRSV free in 2012. Nevertheless, on October 2013 clinical signs compatible with PRRSV were reported in a commercial sow farm. Since then, all commercial herds performed surveillance activities according to a risk score based on location and biosecurity measures. From October 2013 to October 2017, approximately 153,000 blood samples have been analyzed.

Chile eradication of PRRSVViral sequences obtained during the 2013 outbreak were compared to sequences from the early 2000s outbreak in Chile. Results showed a large genetic difference between isolates from both outbreaks. Further analyses demonstrated that the Chilean virus was closely related to a virus circulating in the state of Indiana in the US at the time of introduction. These results suggested that the latest PRRSV outbreak in Chile was most likely due to a new introduction into the country rather than a reemergence of a strain previously detected in Chile.

By October 2017, the disease was restricted to approximately 45,000 animals in six commercial farms owned by two companies that currently have eradication programs in place. These six infected commercial sites are clustered in three areas. (See figure above)

Science Page: Monitoring breeding herd production data to detect PRRSV outbreaks

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week, we are sharing a report from Drs. Gustavo Silva and Daniel Linhares and his team at Iowa State University.

Key points:

  • Systematic monitoring of key production performance indicators allowed for early detection of PRRS outbreaks.
  • Number of abortions was the most efficient parameter, detecting outbreaks up to 4 weeks before being reported to MSHMP.
  • Early detection of signals associated with disease outbreaks may help in preventing further spread of the virus to other herds, and allowing implementation of rapid response intervention(s).

Two-years worth of reproductive performance data from a production system with 14 breeding herds (1,512 herd weeks) was gathered. Weekly data on number of abortions, pre-weaning mortality (PWM) and difference between total born and born alive (neonatal losses), were merged with weekly MSHMP PRRSV status. A statistical process control method was used to scan production data for significant deviations from baseline.

Linhares EWMA application to detect significant deviation in abortions.gif
Example of EWMA application to detect significant deviation in abortions, compared to changes in PRRS status over time.

The time-to-detect outbreak, percentage of early detection of PRRSv-associated productivity deviations, and relative sensitivity and specificity of the production data monitoring system were determined relative to the MSHMP.

Abortion signals were detected 1 to 4 weeks before outbreaks were reported to the MSHMP. Most pre-weaning mortality signals coincided with the outbreak date reported to the MSHMP, and prenatal losses signals were detected from 1 to 3 weeks after the MSHMP reported outbreak date. Overall, the models had high relative sensitivity (range 85.7 to 100%) and specificity (range 98.5% to 99.6%) when comparing to the changes in
PRRS status reported in the MSHMP database.

Science Page: Why PRRS elimination doesn’t work in some herds

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week, we are sharing an article by Dr. Amber Stricker from Suidae Health and Production, published in PigHealthToday.com

“Over the years, there’s been considerable progress in the development of strategies aimed at eliminating porcine respiratory and reproductive syndrome virus (PRRSV). I define successful PRRSV elimination as the absence of clinical disease in the breeding herd and, more importantly, the absence of the vertical transmission of virus to weaned pigs. Unfortunately, successful PRRS elimination isn’t always achieved in some herds, and I have several experiences that may help answer why.”
Dr. Stricker then compiles six reasons that, in her experience, led to a failure in PRRS elimination:
  • No break in disease cycle or insufficient herd closure
  • Incomplete exposure
  • Compliance problems
  • Holding back pigs
  • New virus introduction
  • Insufficient diagnostics

Take a look at the full article to read more about each of those facors.