Assessing a research project ~ with reference to the big picture.

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Assessing a research project with reference to
the big picture.
Grant Shackell, AgResearch Blue sky to deep
water the reality and the promise ANZCCART
Conference 2008 Auckland NZ
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5,000,000
35,000,000
Pastoral agriculture
5,000,000
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Pithomyces chartarum
Sporidesmin
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Toxicity
GGT
GDH
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Facial Eczema
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Treatment

• 3 clinical 50-95 sub-clinical
• no cure
• Zn prophylaxis toxicity
• breed for resistance
• as increases D/R has to increase

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Where is it?
70 of dairy 60 of beef 40 of sheep
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Susceptible or Resistant?
Finnish Landrace (F) rams
h2 0.4
160 Coopworth ewes per ram
by AI
etc.
3 FxT rams
200 half-sib progeny per ram
Sporidesmin challenge
Measure FE traits of progeny (serum GGT GDH
liver injury)
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The protocol

• 2000 animals challenged
• 0.2 - 0.3 mg/kg liveweight
• blood sampled weekly
• good feed supply
• shade
• welfare commitment

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The results

• 60 GGT gt70 (71- 1185)
• animals with elevated GGT/GDH monitored
• 15 clinically affected
• placed indoors in shade
• 0.5 deaths/euthanasia

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The outcome

• very powerful DNA resource
• augment with natural challenge
• whole genome selection (SNPs)

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Was it justified?
There was some ethical cost

• Refinement
• Reduction
• Replacement
• Rationale

Benefit is improved animal welfare
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Annual Risk