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