optimising worm control in prime lamb flocks in south ...13.4 31.3 17.9 lambs from nil ewes 10.7...
TRANSCRIPT
Fred Morley Unit
Optimising Worm Control in
Prime Lamb Flocks
in South Western NSW
Rob Woodgate and Bruce Allworth
Fred Morley Unit
School of Animal and Veterinary Sciences
Fred Morley Unit
• 2012 to 2014 - to determine “Best Practice” (LTL) worm control for prime lamb flocks - lift the limits imposed by worms on sheep meat production
• OPTIMAL ECONOMIC SUSTAINABLE WORM CONTROL
• New England, NSW – UNE (lead) – 6 farms
• Central Tablelands, NSW – LLS – 4 farms
• South Western NSW – FMC CSU – 4 farms
• Victoria – Mackinnon Project (Uni Melb) – 4 farms
• Compare LTL with TYP practice in each region (similar in southern NSW)
Lifting the Limits program
Fred Morley Unit
Fred Morley Unit
• Two trial mobs of ewes on each farm
• Tagged 120 ewes, scanned in twin, in each mob
• 60 ewes were kept ‘worm free’ (SUP) – positive control
• 60 ewes received LTL or TYP treatments
• Weighed, CS, WEC ewes approx. every 2 months (post scan (Apr), pre-lamb (June), lb marking (Aug), weaning (Nov), pre-join (Jan), post scan)
• Recorded lambing percentage and subsequent scanning data
Trial design - Ewes
Fred Morley Unit
Ewe CS averaged 3.2 up to 4.2 at different times over all of the SW NSW farms
Fred Morley Unit
• SUP ewes = ‘worm free’ = production possible from those ewes under their conditions ‘WITHOUT’ WORMS
• Compare DIFFERENCE between SUP and LTL ewes in the same mob
• Compare DIFFERENCE between SUP and TYP ewes in the same mob
• nb. in SW NSW, TYP was close to eventual LTL
Analysis - Ewes
Fred Morley Unit
• Identified to group of ewes at lamb marking
• Tagged – lambs from SUP ewes
• Tagged – lambs from LTL or TYP ewes
• Weighed trial lambs at marking
• Half of each group of lambs was kept ‘worm free’
• Weighed trial lambs again immediately prior to first sale (typically about 8 weeks post-marking)
Trial design - Lambs
Fred Morley Unit
Fred Morley Unit
Fred Morley Unit
Results – Ewes – 2012 to 2014Difference between non-SUP
and SUP over lambing (kg)
Difference between non-SUP+
SUP from initial to last wt (kg)
Year 1 (2012)
LTL farm -1.9 -3.4
Year 2 (2013)
LTL farm -1.2 -1.4
TYP farm -2.4 -1.8
Year 3 (2014)
LTL farm -1.0 -0.7
TYP farm 0.6 -1.2
Ewe WEC typically maximum of 500 to 600 epg during year (unless barber’s pole worm)
Fred Morley Unit
WEC – Year 1 – NSWSWS2
-50
0
50
100
150
200
250
300
350
400
450
21/05/12 04/07/2012* 04/09/12 21/11/12 16/01/2013* 04/04/13
WE
C (
ep
g)
Date of data collection
CAP
LTL
NIL
SUP
Fred Morley Unit
Mean liveweight loss – Year 1 – NSWSWS2
2.7
5.1
12.4
CAP LTL NILSUP
Fred Morley Unit
-30
-25
-20
-15
-10
-5
0
5
10
15
20
21 May-4 Jul 4 Jul-4 Sep 4 Sep-21 Nov 21 Nov-16 Jan 16 Jan-4 Apr
Liv
ew
eig
ht
ch
an
ge (
kg
)
Time period
CAP
LTL
NIL
Liveweight changes – Year 1 – NSWSWS2
SUP
Fred Morley Unit
Weight 1
(kg)
Weight 2
(kg)
Weight
Gain (kg)
Year 1 Lambs from
SUP ewes
13.9 31.8 18.0
Lambs from
NSUP ewes
13.4 31.3 17.9
Lambs from
NIL ewes
10.7 31.3 20.6
Year 3 Lambs from
SUP ewes
15.6 37.1 21.4
Lambs from
NSUP ewes
15.9 38.1 22.1
Lambs from
NIL ewes
15.6 N/A N/A
Results – Lambs
Fred Morley Unit
Results – Lambs – 2012 to 2014• SUP worm treatments (monthly drenching) of lambs
from marking until first sale only had a small and variable effect on lamb weight
• 10 / 17 mobs = < 0.5kg difference in lamb weight gain
• 6 / 7 mobs = SUP lambs 0.7kg to 2.2kg heavier
• 1 / 7 mob = untreated lambs slightly heavier
• Overall mean weight gain was 16.6kg for both SUP and untreated lambs
• Typically untreated lamb WEC averaged up to 200 epg(occasionally 300 to 450 epg on one farm without barbers pole worm)
Fred Morley Unit
Fred Morley Unit
Drench efficacy (DRENCH RESISTANCE)
Farm
½ IVM IVM Mox BZ+LEV BZ+LEV
+OP
BZ+LEV
+IVM
LEV Other Other
SW1 84%* 98% 98% 100% Derq/ABA
SW2 32% 88% 71% 100%
**
79% 48% BZ
SW4* 62%* 100%* 69%* ⅓
Closantel
SW7 83%
****
100% 93% 97% 100% Derq/ABA
SW8 60% 84% 73% 100% 98%
***
SW9 49%
****
88% 92% 100% Derq/ABA
* Haemonchus spp only **BZ+OP and LEV+OP ***Lev x2 **** most spp
Fred Morley Unit
• Prime lamb ewe worm control is a balance between body condition score, nutrition and worm challenge –good CS ewes can be resilient to worm effects
• Effective broad-spectrum pre-lambing worm treatment for prime lamb producing ewes (high stress/risk time)
• must KNOW your drench resistance status
• Lambs generally okay until first draft – monitor WEC and liveweight (> 230g/hd/day +; whp/esi)
• WECs are cheap insurance to avoid production loss and over-treatment (e.g. S/A drench?) - monitor sheep and pasture contamination/worm challenge
Key messages (nb barber’s pole worm)
Fred Morley Unit
• Cooperating farmers
• Industry Advisory Group
• Colin Scrivener
• Student helpers
• Meat and Livestock Australia
Thank You