Identifying indicator traits that can be used to breed for breech strike resistance Johan J h Greeff G ff Senior Geneticist LJE J Karlsson, a sso , AC...
Identifying indicator traits that can be used to breed for breech strike resistance Johan J h Greeff G ff Senior Geneticist LJE J Karlsson, a sso , AC C Sc Schlink,, N U Underwood, de ood, N Stanwyck Sta yc Department of Agriculture and Food WA G Lindon AWI
Obj ti Objectives - Scientific S i tifi • Quantify importance of indicator traits for p in breech strike in un-mulesed sheep summer (Armidale NSW) and winter rainfall (Mt Barker WA) regions • Estimate genetic parameters to design effective breeding programs for multi-trait improvement • Assist industry with ASBVs of indicator traits
A national wool R&D technical update June 2010
I d t issues Industry i with ith un-mulesed l d sheep h •
• •
Are un-mulesed sheep selected on breech indicator traits more resistant to breech strike? What impact on income resulted from selecting sheep on breech indicator traits? Are there sheep that are naturally resistant to breech strike?
A national wool R&D technical update June 2010
Australian A t li W Wooll IInnovation, ti DAFWA & CSIRO Breeding g Project j 2005-2010 Group
Purpose
Select A
Intense selection for resistance both rams & ewes
Select B
Demonstrate progress in a commercial flock (rams only)
C t l Control
U Unselected l t d control t l
Mulesing
Comparing Un-mulesed Select A vs Mulesed Control A national wool R&D technical update June 2010
Acknowledgements Contributing Flocks – WA and NSW Mount Barker, Western Australia 2005 drop ewe weaners: • • • • • • • • • •
Billandri Cherry Tree Estate J Coole & Co Felspar Pty Ltd GSARI C D, D N & S H Herbert Kilandra Pastoral Co Majuba I & D Robertson W M & V A Webb
Ewes for 2006 mating:
DAFWA Research Stations: • Badgingarra • GSARI • Mt Barker
Armidale, New South Wales 2005 drop ewe weaners: Auchen Dhu Park Cressbrook Gostwyck Goyarra Poll Hazeldean Mirramoona Quambaloo Poll Ruby Hills Whyworry Park Yalgoo
Sire flocks 2006 mating:
• Calcookara (Cojack) • Centre Plus • Cherry Tree Estate • Cranmore Park • Rylington Merino • Toland • Yeendalong Farm (Abbott) • GSARI (control) Sire flocks 2007 mating • Wallinar • Margan M • Centre Plus WA • Calcookara (Garreth) • Majuba •Rylington Merino
• Calcookara • Centre Plus • Cressbrook • Parkdale • Quambaloo Poll • Ruby Hills • Severn Park • Toland • T13 (control)
A national wool R&D technical update June 2010
Selection of sires used in WA Rylington Merino
Cojak
Cranmore Park
Garreth
Abbott
O’Halloran
Centre Plus
A national wool R&D technical update June 2010
Original design Screened-in Screened in 600 mature and 600 ewe lambs Mulesed
Un-mulesed
Select A
100
100
Select B
100
100
Control
100
100
600 Mature ewes (from Research flocks) 600 Weaner W ewes (from (f Industry I d t flocks) fl k ) Half progeny mulesed, half progeny unmulesed A national wool R&D technical update June 2010
Design change in WA 2008 Mulesing stopped in 2008, all progeny unmulesed More focus on sire differences rather than selection lines Rylington flock (high worm resistant 600 ewes) added Initial Breech strike flock continued Select A 200 ewes Select B 200 ewes Control 200 ewes A national wool R&D technical update June 2010
Management of flocks •Very intensive monitoring of sheep •Fly activity was monitored with traps •No blanket preventative treatments were applied. •WA - Lambs and hoggets managed to “best” identify resistant and susceptible individuals, crutched just before shearing •Mature ewes normal crutch time to minimise risk of lamb loss •Struck St uc ssheep eep ttreated eated immediately ed ate y with t sshort o t act acting g ttreatment eat e t A national wool R&D technical update June 2010
2005 Drop Industry Ewe Hoggets Intense selection
Control
Bio-clipped
A national wool R&D technical update June 2010
Number of animals – Mt Barker WA Number of sires Number of dams Number of progeny 2005 2006 2007 2008 2009 TOTAL
62 1703 678 437 468 1172 1410 (weaned) 4265
Usable records for f this thi presentation t ti Unused records including 2009 drop
4162 2683
(2009 drop will be included in final project analysis) A national wool R&D technical update June 2010
Fleece Weight is not strongly correlated with Breech Flystrike
A national wool R&D technical update June 2010
Message There are differences in breech strike between cross breeds and large differences between sires within Merino breed
progeny tested breech flystrike resistant Merino sires A national wool R&D technical update June 2010
Elucidating the underlying differences
A national wool R&D technical update June 2010
Breech strike and the indicator traits to hogget age
A national wool R&D technical update June 2010
Breech strike and dag g score to hogget age. 1
P=0.001
Dags dominate all other indicator traits at Mt Barker
Inc cidence of breec ch strike
0.8
0.6
0.4
0.2
0 1
2
3
4
5
Dag score
Adjusted for the other indicator traits
A national wool R&D technical update June 2010
Breech strike and breech cover t h to hoggett age 1
P=0.09
Incidence of b breech strike
0.8
0.6
0.4
0.2
0 1
2
3
4
5
Breech cover score
Adjusted for the other indicator traits
A national wool R&D technical update June 2010
Breech strike and wool colour to hogget age 1 0.9
P=0.18
Incidence of bre eech strike
0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 1
2
3
4
5
Colour score
Adjusted for the other indicator traits
A national wool R&D technical update June 2010
Breech strike and urine stain t h to hoggett age 1
P=0.60
Incidence of b breech strike
0.8
0.6
0.4
0.2
0 1
2
3
4
5
Urine stain score
Adjusted for the other indicator traits
A national wool R&D technical update June 2010
Breech strike and breech wrinkle to hogget age 1
P=0.83
Inc cidence of breec ch strike
08 0.8
0.6
0.4
0.2
0 1
2
3
4
5
Breech w rinkle score
Adjusted for the other indicator traits
A national wool R&D technical update June 2010
Contribution of indicator traits (to hogget age) to breech strike for unmulesed 2005-2008 drops
Unexplained 77.5%
Breech wrinkle 0% Wool colour 0.7% U Urine e 1%
Breech cover 1.1%
Dags 11% Year and sex 7.5% Interaction 2.1% A national wool R&D technical update June 2010
The 4 main indicator traits (17%) and known environmental factors such as year, sex and paddock (8%) currently explain around 25% of all the variation between unmulesed animals that were breech struck
Approx 75% of all the variation between unmulesed animals that were breech struck remained unexplained
A national wool R&D technical update June 2010
For the 2005, 2006 and 2007 drop animals to hogget age age, mulesing explained 26% of the variation in breech strike and the 4 main breech indicators 12% and environmental factors 8% Approx 54% of all the variation between the animals that were breech struck remains unexplained. Causes of adult ewe flystrike (crutched at normal times unlike hoggets) is yet to be analysed A national wool R&D technical update June 2010
Additional indicator traits assessed Faecal consistency score D moisture Dag i t score weaning i Dag moisture score spring Tail wrinkle pre-weaner shearing Tail wrinkle p post-weaner shearing g Breech cover pre-weaner shearing Breech cover post-weaner shearing
A national wool R&D technical update June 2010
Contribution of all indicator traits to weaning and d tto hogget h t age (unmulesed) ( l d) b breech h strike t ik
Breech cover preshearing
Weaning
Hogget
2008 and 2009
2008
Unexplained 78%
Unexplained 61%
DAG Interact
YEAR Tail wrinkle marking
Interact
Wool colour Breech cover post shearing p g
Sex
DAG
Tail wrinkle post shearing
Sire Tail wrinkle preshearing
Dag wetness t Breech cover
Tail wrinkle Breech wrinkle Urine
Wool colour
Breech wrinkle Urine A national wool R&D technical update June 2010
Message IN A HIGH DAGS ENVIRONMENT AND VERY PLAIN FLOCK
•The known indicator traits and environmental factors explain approx 20% of the variation of breech strike and mulesing another 25% •55% of breech strike variation currentlyy remains unexplained and subject of further R&D A national wool R&D technical update June 2010
Effect of indicator traits on the number of lambs weaned per ewes joined Breech Wrinkle 1.2
