PRRSV control and eradication in Spanish farmsEnric Marco

marco i collell; S.L.

PRRS is possible

• “Test and removal” (Dee and Molitor, 1998),• Closed up of the herd (Torremorell and

Christianson, 2001) • Partial depopulation (Plomgaard, 2001)

Critical points

• Persistence of the virus (Zimmerman, et al., 1992) • 152 days in tonsils of infected animals (Wills, et al.

1997) • 92 days in semen (Christopher-Hennings et al., 1995,

Swenson et al. 1994)• Viremic piglets can shed virus up to 7-16 weeks

(Benfield et al., 1996)

Case 1: PRRS eradication in a small farrow to finish herd

The farm

• Year 2,000• 230 sows farm• Farrow to finish herd.• Batch farrowing every 15 days.• Finishing capacity: 50%• Sows: LD x LW• Boars: Pietrain-Halothane (-) (I.A.)

Sus Scrofa (Cal Rech, Barcelona)

The farm

The farm

The farm –health status

• Aujeszky’s disease• PRRS• Mange• Mycoplasma hyopneumoniae• Actinobacillus pleuropneumoniae• Finishing mortality up to 25-30%

Objective

• Eradicate:• PRRS• App• Mange

Eradication plan

• Switzerland eradicate M. hyo from small herds (Zimmerman, 1996).

• Denmark, the same methods are apply in larger herds (Plomgaard, J. 1998)

BASES:• No animals present younger than 10 month of

age.• No replacement during 6 months.• Nursery and finishing depopulation.• Stop farrowing or move them to other facilities.

• Medicate the remaining stock

Eradication plan

• Medication all remaining animals:• 5 injections of enrofloxacin (2,5 mg/Kg. BW) on days

1, 4, 8, 11 and 14.• 2 injections of Doramectin (3 mg./Kg. BW) 14 days

apart.

• Good cleaning and disinfection of empty rooms.

Eradication plan

• Sows wean outside farm were located in isolation during 15 days• Where received Enrofloxacin and Doramectin.• A.I. during this period.

• Remodelling took place during the eradication time.

Eradication plan

Results

• No clinical signs of mange observe till now. • No mange control is done.• No lesions, no clinical signs of App

observed till now.

Results

• M.hyo is still present on the farm.• Replacement come from a positive

source.• Farm produced PRRS negative stock

until December 2001 when became reinfected.

Case 2: PRRS eradication in a small farrow to finish Boar multiplier by total depopulation

The farm

• Year : 2,002• 300 sows farm• Farrow to finish herd.• Boar multiplier• Batch farrowing every week.• Finishing capacity: 50% (boars and replacement) • Sows: LW and (LW x Pt)• IA in the farm: 5 boars: Pietrain

The farm

The farm

The farm –health status

• Mycoplasma hyopneumoniae• PRRS infected in August 2001

BASES:

• Stop positive replacement during 6 months.• Nursery and finishing depopulation.

Eradication plan

Farm lay out

500 m.

GestationFarrowing roomNurseriesFinishing barnsPoultry barns

Eradication starts. January 2002

500 m.

GestationFarrowing roomNurseriesFinishing barnsPoultry barns

Last PRRS negative replacement moved in

Eradication: March 2002

500 m.

GestationFarrowing roomNurseriesFinishing barnsPoultry barns

Last Replacement PRRS (+)

At 3 weeks piglets are weaned outside

Replacement of all AI boars by PRRS (-)

Eradication: September 2002

500 m.

GestationFarrowing roomNurseriesFinishing barnsPoultry barns

Piglets are weaned again inside

Eradication: October 2002

500 m.

GestationFarrowing roomNurseriesFinishing barnsPoultry barns

NEW PRRS negative replacement moved in

Eradication: December 2002

500 m.

GestationFarrowing roomNurseriesFinishing barnsPoultry barns

All samples Show PRRS negative

results

Eradication: January 2003

500 m.

GestationFarrowing roomNurseriesFinishing barnsPoultry barns

PRRS (+)

Eradication continues

• January 2004: same process is done again• October 2004: Positive animals in Finishing

again• EXTERNAL FINISHING HAS NOT BEEN

EMPTIED

Eradication continues

• January 2005: TOTAL DEPOPULATION• May last PRRS (+) sows farrow• July 2005 first sows farrow• To accelerate the program matings has been done out side.• New stock: • PRRS negative• M. hyo negative

Case 3: PRRS eradication in a 3 sites herd

The farm

• Year 2,003• 1.400 sows multiplier farm• 3 sites herd.• Farrowing every week.• Sows: Lw and Ld x Lw• AI boar stud in farm • 6 Boars: LD and (Lw x D)

The farm

The farm –health status

• Mycoplasma hyopneumoniae• PRRS

Farm lay out

> 10 Km.

GestationFarrowing roomNurseriesFinishing barns: Own replacement

SITE 1

SITE 2

EXTERNALSITE 3

> 1000 Km.

Future farm lay out

> 10 Km.

GestationFarrowing roomNurseriesFinishing barns: Own replacementand gilts to sale

SITE 1

SITE 2

SITE 3

3 Km.

800 m.

BASES:

• Stop positive replacement during 6 months.• Nursery and finishing depopulation. Using the

possibility of new facilities.

Eradication plan

Eradication Plan

• March 2003: Last replacement PRRS (-)• June 2003: Last replacement show titers to PRRS• June 2003: Inside nurseries emptied• July 2003: 4 weeks after, weaned pigs moved to

new sites 3 (wean to finish)• Own replacement and few more to fill up barns.

Eradication Plan

• July 2003: inside nurseries emptied• October 2003: Inside Finishing barn emptied• November 2003: New PRRS replacement located

in new inside finishing barn.• Managed independently.

• November 2003 old inside finishing remodeled to gestation

• December 2003: • Elimination of any gilt or sow PRRS (+) not mated.• Stop using PRRS (+) boars

Eradication Plan

• February 2004: Replacement in new site 3 negative to PRRS is moved to site I.

• March 2004: last farrowings from PRRS (+) sows• April 2004: first farrowing from new PRRS (-) gilts.• April 2004: weaners moved to new Site 2.• April 2004: Old site 2 is emptied.

Results

• Up today all analysis have shown negative results form all sites.

Production gaps

• Form last replacement negative to become positive: 3 m.

• From last replacement negative to first weaners (future replacement on external site) that remain on farm: 4 m .

• From last replacement once positive to new replacement negative: 5 m.

Case 4: PRRS eradication in a 3 sites herd without partial depopulation

The farm

• Year: 2,006• 800 commercial farm• 3 sites herd.• Farrowing every second week.• Sows: Ld x Lw• AI boar stud in farm • 4 Boars: Pietrain

• Own replacement• GP’s external source

The farm

Site 1

Site 2

The farm: site 1

Gestation

Farrowing

Own replacement

The farm: site 2

History

• 400 sows close herd• 1992 PRRS infection• 1998 control PRRS• Own-replacement• Gp’s + F1 acclimatization (contact with viremic pigs)

• 2002 • Change to 3 sites system• Increase population from 400 sows to 750

• 2006• PRRS circulating on site 2 + 3• No circulation on sow herd

The farm –health status

• Mycoplasma hyopneumoniae• PRRS

BASES:

• Stop positive replacement during 1 month.• No nursery depopulation

Eradication plan

Eradication Plan

1. Stop recirculation on site 2 (8-9 weeks of age)• Increase Biosecurity among batches• Different boots per barn• Specific material per barn (syringes, medicines, etc)

2. Once recirculation on site 2 stops (week 0)• Stop introduction of F1 on site 1 (once first batch is

detected negative) one month (two consecutives batches).

• Move negative F1 from site 2 to isolated external finishing and keep them isolated. (week 2)

The farm: site 2

Eradication Plan

3. Control PRRS status on site 2 (week 12)4. Control PRRS status last replacement PRRS positive

still on farm by PCR (week 16).• If PCR negative• Move negative F1 to site 1 (week 20)• Breed negative F1 (week 26)• Keep them isolated from the rest of the sows util gestation is

confirmed (4 weeks)

5. Week 30: Herd come back to normality

Results

• Farm has been PRRS negative up to January 2012

Production gaps

• From last replacement positive to new replacement negative: 1 m.

• But new replacement kept in isolation during 6 months.

Conclusions

• PRRS elimination is possible, but not always easy.

• People on farm have to be involved on the project.

• Replacement and weaners are critical areas for PRRS control.

• Good location and biosecurity are essential to maintain PRRS free status.

Thank you for your attention