Assessing impact of 1-7-4 on

wean to finish pig health

Daniel Linhares, Ian Levis, Katie Wedel, Carl Betlach, Bob

Morrison

Field epidemiology

• Investigation of acute population problems

• Gathering information (clinical medicine, laboratory diagnostics, basic epidemiology (time/person/place), common sense)

• Data decision tools

Goals

#1 Understand WTF mortality drivers

#2 Assess 174-PRRSv role on

mortality and on profit (loss).

Materials and Methods

• Developed a model* to combine

information from difference sources to

explain a health-associated parameter

(mortality):

– Swine health information (SHMP)

– Sow farm parameters

– Management parameters

– Closeout (growing pig performance) data

* Hierarchical mixed model using SAS University Edition Proc Glimmix

2,080 closeouts7,323,511 pigs41 sources

1,465 closeouts4,431,762 pigs

35 sources

Single source

Wean to finish

462 closeouts2,362,511 pigs

33 sources

Single sourced, WTF flows mortality

Log-transformed Mortality

6.5%

30%1.2%

Summary of effect of parameters on Mortality

Variable Levels Significant?

Feed Mills N=12 YES

Supervisor N=30 YES

Pct Utilization Continuous YES

Sow farm PRRSv status 1, 2v, 4 YES

Start weight Continuous YES

PRRS type (174, other, none) YES

Sow farm PEDv status 1, 2v, 4 TREND

Gilt type Bred vs 270lb TREND

Density Continuous NO

Average Parity # Continuous NO

Herd Parity # Continuous NO

Empty days before start Continuous NO

Positive stable,

ongoing live vaccine

exposure

Positive unstable

~ Stable sow farm

1-7-4 PRRS

“other” PRRSv

Stable sow farms

Positive stable, ongoing program

Positive unstable

~ Negative

Feed Mills

A B C D E F G H I J K L

Feed mill effect

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 1 2 3 4

Supervisors

Supervisor effect

Gilt program type

MULTIVARIATE MODEL

Actual vs predicted mortality (95% prediction ellipse)

Variables. PRRS virus (174, other, none); Weeks on PRRSv status (nested with source); Start quarter (time); Gilt type; Supervisor; Feed Mill; PEDv status; Pct utilization WTF

Act

ual

Mo

rtal

ity

Predicted Mortality

PRRSv 174 adjusted effect

• After adjusting by other significant

covariates,

– No difference between Neg and Other PRRS

– 1-7-4 flows had additional 4.8% mortality

Economic impact

• After adjusting to other significant

variables, 1-7-4 PRRSv flows had a

reduction of $ 2.87 / head on profit (R2

0.78)

Conclusion

• Model accounted for 81 % of observed

variability.

• Wean-to-finish mortality was increased

significantly when:

– Infected with 174 PRRSv = 4.8% additional

mortality

– Infected with 174 PRRSv = reduction $2.87 profit

Thank you

Daniel Linhares, DVM, MBA, PhD

Assistant Professor, Veterinary Diagnostic and Production

Animal Medicine Department

Director of Graduate Education, VDPAM

College of Veterinary Medicine, Iowa State University

O: +1-515-294-9358

M: +1-515-357-1044

linhares@iastate.eduhttp://field-prrs.blogspot.com