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

~ 5,000,000

~ 5,000,000

~ 35,000,000

Pastoral agriculture

Pithomyces chartarum

Sporidesmin

Toxicity

GDH

GGT

Facial Eczema

Treatment

3% clinical = 50-95% sub-clinical

no cure

Zn prophylaxis – toxicity

breed for resistance as increases D/R has to increase

Where is it?70% of dairy60% of beef40% of sheep

Susceptible or Resistant?

etc.

160 Coopworth ewes per ram

200 half-sib progeny per ram

by AI

3 FxT rams

Finnish Landrace (F)rams

Texel (T) ewes

Measure FE traits of progeny(serum GGT & GDH + liver injury)

Sporidesmin challenge

h2 ≈ 0.4

The protocol

2000 animals challenged

0.2 - 0.3 mg/kg liveweight

blood sampled weekly

good feed supply

shade

welfare commitment

The results

60% GGT >70 (71- 1185) animals with elevated GGT/GDH monitored

15% clinically affected placed indoors in shade

0.5% deaths/euthanasia

The outcome

very powerful DNA resource

augment with natural challenge

whole genome selection (SNPs)

Was it justified?

Refinement

Reduction

Replacement

Rationale

There was some ethical cost

Benefit is improved animal welfare

0

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60

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80

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4-Jan 18-Jan 1-Feb 15-Feb 1-Mar 14-Mar 28-Mar 11-Apr 25-Apr 9-May 23-May

Week ending

% e

lev

ate

d (

>3

0,0

00

/ha

)

2005

2006

2007

2008

Annual Risk