Donghuo Jiang, Montse Torremorell, Hui Gong and Ana Carolina Guerrelhas

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SPF and SPR Lines Myths and Realities Are They
Possible in Brazil?
Donghuo Jiang, Montse Torremorell, Hui Gong and
Ana Carolina Guerrelhas SyAqua, Kentucky, USA
FENACAM, March 2006
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Outline

• Introduction
• Myths of SPF Concept Development
• Myths of SPR Concept Development
• Application of SPF and SPR
• Summary

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World shrimp aquaculture production
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World shrimp aquaculture production
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• Shrimp disease has caused economic losses in
  billions.

• Is still considered as the most limiting factor
  in shrimp culture!

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Combat with shrimp diseases

• Prevention
• Site, Species
• High health stock SPF, Earlier diagnostics,
  Biosecurity
• Management Reduced water exchange, Better
  feeding practice

SPF

• Control
• Disinfectants, Immunostimulants, Immunotherapy
  (Vaccines-like)
• Antibiotics, Probiotics, etc.
• Inconsistent results and Costly

• Genetically improved shrimp
• SPR specific strait
• Long-term solution and economical viable

SPR
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Outline

• Introduction
• Myths of SPF Concept Development
• Myths of SPR Concept Development
• Application of SPF and SPR
• Summary

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SPF Specific-Pathogen-Free

• SPF working lists
• Not globally recognized
• Office International des Epizooties (OIE)
• U.S. Marine Shrimp Framing Consortium (USMSFC)
• A Dynamic list
• Criteria for pathogens to be listed
• Excludable
• Available/Adequate diagnostic detection method
• Significant threat of disease and production
  losses.

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USMSFP Working List of Specific Pathogens for
"SPF" Penaeids in US1
1 As of August 2003 OIE listed
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• SPF misconception
• Not disease free, only refer to Specific
  pathogen(s)
• Not a heritable trait, only designate to Health
  status
• Not innate resistance nor susceptibility to a
  pathogen
• Associated with rearing facility, not warrant
  shrimp health status.

• A SPF shrimp can still carry pathogen that is
  not listed or pathogen that is listed but at very
  low prevalence below the current detect limit !!!

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SPF Development
Founder Population
SPF
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• Premium health SPF concept
• Promoted by SyAqua
• Backup by Health Assurance Program
• Both SPF and generally healthy
• Biosecure Shrimp Genetic Nucleus

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Outline

• Introduction
• Myths of SPF Concept Development
• Myths of SPR Concept Development
• Application of SPF and SPR
• Summary

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SPR Specific-Pathogen-Resistance

• Definition
• Resistance to one or more specific pathogen(s).
• Health status can be SPF or non-SPF
• A heritable trait
• SPR vs. General robustness
• High research priority rated by shrimp industry

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SPF and SPR development

• SPF shrimp
• Biosecurity implementation

• SPR shrimp
• Genetic selection for resistance

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Shrimp disease resistance/tolerance

• Species specific

• Environmental influences

• WSSV high temperature, low salinity
• NHP high temperature, high salinity
• Virus interaction IHHNV-WSSV

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SyAqua Genetic selection for disease resistance

• 2003-2004 TSV-C WSSV
• Total 150 families tested
• Two phases 2g and 15g
• Gene expression study

• 2004-2005 TSV-C/TSV-B, WSSV IMNV
• Total 45 families tested
• One phase 3g
• WSSV massive bioassay 174 families

• Global integration know-how, markers,
  germplasm, etc.

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Correlation of TSV resistance at two different
size stages
TSV
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SyAqua Genetic Selection for TSV resistance
Significantly higher TSV survival rate (20)
demonstrated by Selected families (TSV-R)!
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SyAqua Genetic Selection for TSV resistance

• sRNA virus, high mutation rate
• Hawaii strain Type-A
• Mexico-Strain Type- B
• Belize strain Type-C
• Positive correlations

• Current selection strategy is effective, and
  rapid improvement has been achieved!

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Correlation of WSSV resistance at two different
size stages
WSSV
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Gene expression study

• Disease challenge experiments

RNA/DNA samples and data
Marker discovery
Genetic markers
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SyAqua Genetic Selection for IMNV resistance

• Newly emerging disease many unknown

• Not cause massive mortality under laboratory
  challenge test

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Selection for disease resistance -- Breeding
with WSSV survivors from field?

• Lab challenge tests
• lt 0.1 survivors ? No differentiation shown

• Field observations 5-30 survivors

• Claims of success F. chinensis L.
  vannamei

• Questions
• Why are the results from lab tests and from
  field so different?
• Is selection of WSSV survivors from commercial
  production effective?

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2004 Massive WSSV Challenge Test (Bioassay)

• All 174 families
• 120 non-tagged shrimp/Family

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2004 WSSV Biassay Mortality curves

• Tank 34 mass mortality initiated after Day 4
• Tank 12 no mortality till Day 10.
  Re-introduced infection, then mass mortality
  occurred

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Selection for disease resistance -- WSSV-R?

• Current methodology cant differentiate families
  effectively
• Difficult to control infection levels not
  evenly infected
• Horizontal transmissions cannibalism, contact,
  etc.
• Waterborne route equivalent to Oral infection.

• Breeding with survivors
• Select for less-aggressive behavior or WSSV-R?
• Innovative methodology MAS, etc.

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Outline

• Introduction
• Myths of SPF Concept Development
• Myths of SPR Concept Development
• Application of SPF and SPR
• Summary

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Impacts of disease outbreak
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Paradigm Shift

• Switch to different species
• Thailand P. monodon ? L. vannamei
• China F. chinensis ? P. monodon ? L. vannamei
• Mexico L. stylirostris ? L. vannamei
• Monitor seed stock
• Biosecurity concept
• SPF/SPR concept
• High density culture in smaller ponds
• Greater control over variables
• Lower costs of production

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SPF/SPR application example

• SPF stock
• L. vannamei P. monodon
• BioZEST 8 kg/m2
• Biosecure Zero-Exchange Shrimp Technology
• SPR stock
• IHHNV L. stylirostris
• TSV L. vannamei
• Examples
• Thailand, 2002
• Texas, USA 2004
• Venezuela, 2004

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Questions

• How to make a right choice for a given
  environment ?
• Is SPR still needed when SPF postlarvae are used
  ?
• Are Biosecure production systems necessary when
  using SPR postlarvae ?

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SPF /SPR Conflict, Compromise or Opportunity ?
Wild shrimp
Health upgrade
Genetic improvement
SPR
SPF
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SPF /SPR Conflict, Compromise or Opportunity ?
Wild shrimp
Health upgrade
Genetic improvement
SPR
SPF
SPF/SPR
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Outline

• Introduction
• Myths of SPF Concept Development
• Myths of SPR Concept Development
• Application of SPF and SPR
• Summary

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Summary

• SPF
• Not disease free!
• Not heritable!
• Not more susceptible!
• Always reduce risks of production losses !!

• SPR
• Only to one or more specific disease!
• Different from robustness
• Health status SPF or Non-SPF

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SPF /SPR Conflict, Compromise or Opportunity ?

• Choice of SPF or SPR is based on
• Existing production systems
• Intended health management strategy
• Specific disease of concerns
• In general, biosecure facility should stock with
  SPF shrimp open ponds can stock with either SPF
  or SPR.

• Biosecurity important! Even for where SPR shrimp
  are stocked!!

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SPF /SPR Conflict, Compromise or Opportunity ?

• Challenge of disease problems and low shrimp
  price led to a transition period during which
  shrimp business is being consolidated and new
  production strategies are being adapted.
• Global shrimp consumption/demand will continue
  to rise and shrimp industry will emerge and
  expand again, those who can take advantage of the
  opportunity will have a better chance to succeed.
• From a breeding perspective, genetically
  improved shrimp (e.g. SPR) with premium health
  SPF status will soon become the main seed source.

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SPF/SPR Lines Are They Possible in Brazil?

• Challenges of Brazil
• IHHNV
• TSV
• NHP
• IMNV
• WSSV

• Experience/Lessons from other countries!
• Adaptations to face the challenges!

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SPF/SPR Lines Are They Possible in Brazil?
5 shrimp aquaculture
2 shrimp capture

• Aquatec is striving to deliver
  genetically-improved shrimp (SPR) with premium
  health SPF status!

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SyAqua Delivering genetic improvement to shrimp
producers globally
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