Dr. David Baumert - In-Field Research & PCV2 Sow Herd Stability: Our Process

In-Field Research & PCV2 Sow Herd Stability: Our Process

© Copyright Cargill, Incorporated 2012. All rights reserved.

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In-Field Research &

PCV2 Sow Herd Stability:

Our Process

Dr. David Baumert

February 28, 2014

Dallas, Texas



Veterinarian’s Oath

• Being admitted to the profession of veterinary medicine, I

solemnly swear to use my scientific knowledge and skills

for the benefit of society through

– the protection of animal health and welfare,

– the prevention and relief of animal suffering,

– the conservation of animal resources,

– the promotion of public health and

– the advancement of medical knowledge.

• I will practice my profession conscientiously, with dignity

and in keeping with the principles of veterinary medical

ethics.

• I accept as a lifelong obligation the continual improvement

of my professional knowledge and competence.

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Questions and thought process

• What is the Infection Chain™ of PCV2 in our herds?

– Clinically, subclinically

– What are our expectations of PCV2 control?

• How does vertical transmission of PCV2 impact our growing pigs?

– Does it matter?

– What tools do we have to determine status?

• How do we intervene to make an impact on PCV2?

– How do we measure impact?

– Is the intervention successful?

– What is the ROI?

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Evidence-based decision making

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Domains that influence evidence-based decision making. Source: Satterfield JM et al.



Example of Cargill Pork flow to put

discussion into perspective

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12 Stand-alone Gilt grower sites; rotational, all-in/all-out fill

Gilt Developer/Breeder

continous flow, multi-source

16 Stand-alone, 700-head sow farms

20,000 head, 6-farm, sow system

Commercial nursery system (multi-sourced) Commercial nursery system (multi-sourced)

Commercial finisher system (multi-sourced) Commercial finisher system (multi-sourced)

INTERNAL NUCLEUS / MULTIPLICATION



Our PCV2 Infection Chain™

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Sampling for Sow Herd Stability

• Pigs/Fetuses

– Fetal Hearts

– Pre-suckle Serum

– PUCS – Placental Umbilical Cord Serum

• Sows

– Oral fluid

– Serum

• Environment

– Swabbing

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Placental umbilical cord blood (PUCS)

Photos courtesy of Tom Fangman, Tyler Te Grotenhuis



Progression of PUCS sampling

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Validation of PUCS

Intra-herd variation

Validation of PUCS


Inter-herd variation

Sampling protocol



PUCS – Placental umbilical cord serum

Baumert, Leman 2013

0

10

20

30

40

50

60

70

80

90

100

Sow Serum Litters ≥ 1 pig pos.

PUCS Enviro. Cloth

Perc

en

t P

osit

ive,

%

Site A Site B

53 PCV2 positive pre-suckle pigs out of 168 pigs tested (31.5% positive)

17 PCV2 placenta positives out of 21 litters tested (81% positive)

Average of 32.1% pigs PCV2 positive/litter (Range 0% to 100% positive/litter)




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Validation of PUCS


Validation of PUCS



Sampling protocol


Sampling protocol

Impact on Performance

Risk Factors



How many sampling periods are needed?

One-way ANOVA Analysis of Variance P<0.001

The variance in the

level of viremia in

positive PUCS samples

over time

is significantly different

30 day 30 day

Farm A



Percent positive PUCS samples per

three 30 day time periods per 6 farms

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0

20

40

60

80

100

A B C D E F

Pe

rce

nt

po

sit

ive

, %

Farm ID

Period 1 Period 2 Period 3



88%

90%

92%

94%

96%

98%

100%

A B C D E F

Live born percent Conception Rate, %

Performance of the herd populations tested

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20%

40%

60%

80%

100%

120%

140%

160%

180%

A B C D E F

Still born, % from mean

Mummies, % from mean

• Conception rates were similar between sites

• B, C and D farms had lower Live Born

(as a percentage of total born) than A, E, F

• B, C, D were 3 highest stillborn and mummies

Stillborn and mummies,

percent deviation from group mean, %

Live born and conception rate

percent, %

* Live born percent = live born mean / total born mean



Can we make an impact on stability?

• Options for making an impact

– Biosecurity

• Internal biosecurity – McRebel™

– Herd Closure

– Gilt Acclimation

– Vaccination

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0%

20%

40%

60%

80%

100%

1 2 3 4 5 6 7

Pe

rce

nt

Po

sit

ive

PU

CS

sa

mp

les

, %

Month Sampled

Farm B Farm C Farm D Farm E

Interventions and the impact

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Closed the herd

Mass vaccination

Mass vaccination

Control herd

no action taken



Where does instability of the sow herd start

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Gilt development and PCV2 – first look

• Initial finding into GDU supplying PCV2 unstable sow herd

– Negative (by serum PCR) gilts are entering the GDU

• Hypothesis: negative or naïve gilts entering the sow herd may be

amplifying PCV2 instability in the sow herd

• Incomplete evidence: herd closure in 1 herd coincided with herd

stabilization

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0%

20%

40%

60%

80%

100%

1 2 3 4 5 6 7

Farm B



Summary – findings and observations

• PCVAD is not a big concern in PCV2 vaccinated pigs in our system

– Vaccination works

• Vertical transmission occurs in all herds tested

– Levels vary

• PUCS sampling is a good sample to test for sow herd stability

– More positives found than with sow serum

• PCV2 was widely present in the environment

• A minimum of 3 sampling periods are necessary

– More might be needed…further evaluation is needed

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Summary – findings and observations (cont)

• In 3 herds that had highest measured PUCS positive samples:

– Similar conception rates

– Fewer live born percentage, higher mummies and stillborns

• Interventions (herd closure and mass vaccination with CircoFLEX®

coincided with detection of stabilization

– Repeatability needs to be tested

• Gilt (in gilt development) surveillance and projects are ongoing

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Summary - beliefs

• Current PCV2 vaccines protect pigs through marketing

– We are only trying to tweak, and optimize PCV2 control

• The Infection Chain™ and vertical transmission with PCV2 is real

• Additional work is required to determine the production and economic

impact, if any, of PCV2 presence at birth

• The risk factors for PCV2 sow herd stability/instability are

unclear to date

• We will continue to work on PCV2 at the gilt, sow and pig levels

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Validation of PUCS


Validation of PUCS




Sampling protocol

Impact on Performance

Risk Factors

Risk Factor Analysis

Research herd inclusion criteria

Documents

Dr. David Baumert - In-Field Research & PCV2 Sow Herd Stability: Our Process