Optimising Worm Control in Prime Lamb Flocks in South Western NSW

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1 Optimising Worm Control in Prime Lamb Flocks in South Western NSW Rob Woodgate and Bruce Allworth School of Animal and Veterinary Sciences

2 Lifting the Limits program 2012 to 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)

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4 Trial design - Ewes 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

5 Ewe CS averaged 3.2 up to 4.2 at different times over all of the SW NSW farms

6 Analysis - Ewes 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

7 Trial design - Lambs 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)

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10 Results Ewes 2012 to 2014 Difference between non-sup and SUP over lambing (kg) Difference between non-sup+ SUP from initial to last wt (kg) Year 1 (2012) LTL farm Year 2 (2013) LTL farm TYP farm Year 3 (2014) LTL farm TYP farm Ewe WEC typically maximum of 500 to 600 epg during year (unless barber s pole worm)

11 WEC (epg) WEC Year 1 NSWSWS CAP SUP LTL NIL /05/12 04/07/2012* 04/09/12 21/11/12 16/01/2013* 04/04/13 Date of data collection

12 Mean liveweight loss Year 1 NSWSWS SUP CAP LTL NIL

13 Liveweight change (kg) Liveweight changes Year 1 NSWSWS May-4 Jul 4 Jul-4 Sep 4 Sep-21 Nov 21 Nov-16 Jan 16 Jan-4 Apr CAP SUP LTL NIL Time period

14 Results Lambs Year 1 Year 3 Lambs from SUP ewes Lambs from NSUP ewes Lambs from NIL ewes Lambs from SUP ewes Lambs from NSUP ewes Lambs from NIL ewes Weight 1 (kg) Weight 2 (kg) Weight Gain (kg) N/A N/A

15 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)

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17 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

18 Key messages (nb barber s pole worm) 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

19 Thank You Cooperating farmers Industry Advisory Group Colin Scrivener Student helpers Meat and Livestock Australia