Assessing a research project ~ with reference to the big picture. Grant Shackell, AgResearch “Blue sky to deep water: the reality and the promise”
Jan 29, 2016
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
10
20
30
40
50
60
70
80
90
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