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Sheep lice in WA - some current issues Brown Besier Dept. Agriculture and Food WA Albany Supporting your success Eneabba General Store Livestock Expo March 2014
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Supporting your success The sheep lice picture Chemical choice Chemical application
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Sheep lice in WA How many farms in WA with lice ? 60 % ? How many sheep owners treat in any one year ? 80% ? How many treat every year, whether see lice or not? 71%
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-Suspect light infestations ? - Protect against re-infestation ? Query the need to treat if sure no lice present Why routine treatment ?
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What’s NOT likely to eradicate lice ? Chemicals where resistance by lice is common Insect growth Regulators (IGRs) Synthetic pyrethroids (SPs) Long wool treatments Ineffective application methods Chemical choices
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Chemical choices: off shears/short wool GROUPAPPLICATIONEXAMPLES AbamectinBacklinerMaverick Mag. FluosilicateDipFlockmaster OrganophosphatesBacklinerEureka Gold DipAssassin, Wham Cage dipDiazinon NeonicinoidsBacklinerAvenge DipPirhana SpinosynsBacklinerExtinosad DipExtinosad IGRBacklinerMagnum, Zapp, Clik+ DipFleececare, Strike Synthetic pyrethroidBacklinerCypermethrin DipFleececare Examples only - Dept.Agric and Food WA does not endorse any specific product. IN WA 2013 - Offshears treatments: Pour-on: 78% Dip: 22% IGR or SP: 12%
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Chemical application issues Shower and plunge dip failures Getting the sheep wet: Dip design Time in dip Automatic jetting races No lice treatments registered Don’t wet, won’t eradicate Incorrect chemicals Diazinon by plunge or shower dip
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More information
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Blowfly strike management in WA Brown Besier Dept. Agriculture and Food WA Albany Supporting your success
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Reducing susceptibility to flystrike - management and/or genetics
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Susceptibility factors Dags Skin wrinkle Breech cover Long moist wool Yellow wool, urine stain Dermo, fleecerot Physical injury - blood/ wounds Most important factors determine prevention strategies -Season -Local environment - Individual farm -And appropriate prevention strategies -Management -Genetics
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Susceptibility factors Dags Skin wrinkle Breech cover Long moist wool Yellow wool, urine stain Dermo, fleecerot Physical injury - blood/ wounds
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DAGS The major breech-strike risk factor in most environments Example: 2 weaner flocks, dags vs flystrike
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Proportion of sheep in each dag score 0% 20% 40% 60% 80% 100% 12345 Dag score % Incidence of strike with dag score - some examples in weaners (NEED MORE DESCRIPTION ABOUT THE FIGURES) Proportion of sheep in each dag score 0% 20% 40% 60% 80% 100% 1234 Dag score percentage n=1019 n=122 0% 20% 40% 60% 80% 100% 12345 dag score % breech strike n=122 Incidence of strike in each dag score 0% 20% 40% 60% 80% 100% 12345 dag score % breech strike Incidence of strike in each dag score n=170 n=1058
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Dags and relative risk of flystrike Relative risk of flystrike in weaners x4 x7 x21
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Dag prevention : -Pre-lamb ewe worm management - pasture selection - drench ? -Worm egg counts to check burdens/ pasture contamination -Planned annual worm control program -Genetic: -Cull repeat-offenders (ewes) -Breed against scouring (hoggets)
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BREECH WRINKLE A major strike factor – high genetic hereditability
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SKIN WRINKLE Lambs from 2 different sires:
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Current flock: average breech wrinkle score = 3 4% 28% Example scenario: all selection on wrinkle only
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Current flock: average breech wrinkle score = 3 10 years time: Average breech wrinkle score = 2.2 4% 21% 6% 28%
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DAGS Results after 10 years: Reduced wrinkle by 0.8 of a score: Maintained FD, body weight, reproduction Loss of fleece weight: - 20% Balanced selection: Sires that combine desired traits Culling bad-trait ewes
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GENETICS AND FLYSTRIKE Dags Dagginess Worm resistance Breech wrinkle Bare breech Bodystrike Conformation Neck and body wrinkle Fleece type/ structure Skin disease – dermo, fleecerot Wool - colour etc Individual sheep struck for “no reason”
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Chemical planning assistance Smart phone app:
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“Sheep measles” – an unnecessary cause of loss to sheep producers Brown Besier Dept. Agriculture and Food WA Albany Supporting your success Eneabba General Store Livestock Expo March 2014
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“ Sheep measles” = Cysticercus ovis = Taenia ovis = “ovis ” - A larval tapeworm in sheep muscle: - visual blemish - carcass downgrading or rejection
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Tapeworm in dog intestine Tapeworm eggs on pasture eaten by sheep Sheep meat or offal eaten by dog Tapeworm develops from cysts Eggs develop to cysts in muscle g Wild dogs ? Foxes ? X
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No signs of tapeworm infection in dogs or sheep Cysts remain in sheep for life
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How many properties affected ?
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g PREVENTION … Faecal contamination of pasture -Dogs roaming -Other dogs Dog access to sheep meat -Carcasses -Rations Worm dogs !
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Worming dogs for tapeworms Use tapeworm-specific products: praziquantel (Droncit, Paratak, Popantel, Tapewormer) In some all-wormers - but need less often Ideally treat 4-5 weekly But 3-4 times/year will go a long way An area treatment approach needed: - neighbours, contractors, visitors
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