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4TH MERIAL FORUM
HAVE WE GOT PCVD &
SWINE INFLUENZA UNDER
CONTROL?
PCV2 serological status of gilts at their arrival in commercial
farms
Dr G. PERREUL, Dr B. BOIVENT and Dr J.-B. HERIN
MERIAL SAS, St Herblon, France
2
Content
• Replacement gilts: why is it important to know their PCV2 status?
• PCV2 gilt status in France: results of a field survey
• Impact of CIRCOVAC vaccination on gilts: a field example
• Conclusion: how to manage PCV2 immunity status in replacement gilts?
3
Context: replacement gilts
• Quarantine is a crucial step for future breeders: –observation –adaptation –growth
• PCV2 antibody titers are indicative of: – immune status –ability to resist to a new PCV2 exposure
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Context: is there a risk to gather in gilts with low PCV2 Ab titers?
• Sarli G. et al., ESPHM 2010, Hannover
– the gilt with the lowest anti-PCV2 antibody titer showed:
• the highest number of positive tissues and fetuses
• the longest lasting viremia
Objective
• To assess PCV2 antibodies level and homogeneity
– level: low – moderate – high mean value
–homogeneity: variation coefficient (VC)
• In different nucleus farms
• In different nucleus companies
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Materials and methods
• PCV2 ELISA test
– SERELISA® PCV2 Ab (Synbiotics)
–Reproductibility
• 30% of variation: «normal» for the test (L. Mieli, LDA22, Pers. Comm.)
• Variation coefficient from PCV2 gilt Ab titers
– CV ≤ 30 % => within the intrinsic variability of the test
– CV > 30 % => means a biologically significant difference
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Materials and methods
• 30 nucleus farms
• Supplying 4 large French pig companies
–25% of French pigs produced
• No PCV2 vaccination on gilts
• 5 gilts/farm sampled per sampling session
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Materials and methods
• SERELISA® PCV2 Ab (Synbiotics)
• Thresholds for the mean Ab levels:
Low Moderate High
≤ 3.2 3.2< <4.0 > 4.0
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Results
• All companies
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% of Nucleus farms by category
Results
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Discussion, conclusion
• Wide variety of average titers, meaning different exposure to PCV2 antigen during the growth period: – among companies
– among gilts in the same company
• Need to improve and homogenize gilt immune status against PCV2 before they face exposure by the commercial sows -> vaccination in quarantine
13
An example from the field
• Materials and methods – farrowing farm expanded from 450 to
800 sows
–150-gilt delivery every 6 weeks originating from a single source
– samples in three consecutive batches (10 gilts)
–gilts raised in a remote site
– reproductive performance individually recorded
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An example from the field
• Results prior vaccination
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An example from the field
• Variations in mean batch titres
– moderate to high
– VC higher in batches with low mean titres
Decision made
to vaccinate gilts at arrival:
CIRCOVAC® 2 x 2ml, IM, 3 weeks apart
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An example from the field
• Effect of vaccination on the Ab titres
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An example from the field: reproduction performance
• Fecundation rate
– 94 %
• Farrowing
– still-born: 9.4 % per sow
–mummies: 2.4 % per sow
–weaned: 11.7 piglets per sow
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Conclusion
• PCV2 immunity in gilts is highly variable and unpredictable
• High and homogeneous titers are beneficial
• CIRCOVAC vaccination in gilts is strongly recommended
–2 x 2 ml in quarantine
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Thanks for your attention!
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4TH MERIAL FORUM
HAVE WE GOT PCVD &
SWINE INFLUENZA UNDER
CONTROL?