farmers postcard weeds and livestock...pyrrolizidine alkaloids toxins damage the liver +/- lungs and...
TRANSCRIPT
Lou Baskind BVScDistrict Veterinarian Local Land Services(02) 4842 [email protected]
Farmers Postcard
Weeds and Livestock
© State of New South Wales through Department of Industry 2019. You may copy, distribute, display, download and otherwise freely deal with this publication for any purpose, provided that you attribute the Department of Industry as the owner. However, you must obtain permission if you wish to charge others for access to the publication (other than at cost); include the publication in advertising or a product for sale; modify the publication; or republish the publication on a website. You may freely link to the publication on a departmental website.
• Physical impediments or injuries
• Malnutrition
• Poisonings
What problems can common weeds cause in livestock?
• Impediments• Restricts access to water points
• Restricts access to feeding areas
• Limits movement and mustering
• Spines can cause injury
• Livestock can get stuck
• Injury• Physical damage to eyes, ears, feet
and mouth
• Wool contamination
Physical impediments or injuries
Physical impediments or injuries examples
BlackberryRubusfruticosusspecies aggregate
GorseUlex europaeus
Sweet BriarRosa rubiginosa
Physical impediments or injuries examples
ThistlesE.g. Illyrian Onopordum illyricum; Scotch Onopordum acanthiumSaffron Carthamus lanatus
NoogooraburrXanthium strumariumsyn. Xanthium occidentale
Cathead / CaltropsTribulusterrestris
• Tangled prickly stems
• Dense thickets
• Sharp spines
• Palatability problems
Image 2
Physical impediments or injuries
Wool contamination
• Reduces price (extra processing)
• Injuries / uncomfortable to handle
• Damages equipment
Wool contamination
Saffron Thistle Carthamus lanatus
Bathurst BurrXanthium spinosum
Noogoora burrXanthium strumarium
Cathead / CaltropsTribulus terrestris
• Reduces price (extra processing)
• Injuries / uncomfortable to handle contaminated wool
• Damages equipment
• Eyes, ears, feet and mouth
• More susceptible to other health problems
• Scabby mouth
• Pinkeye
Physical damage
Scabby mouth in sheep Pinkeye in cattle Pinkeye
Thistles Burrs
Physical damage examples
Malnutrition
• Competes with better quality pasture
• Unpalatable
• Poor nutritional content
• If too fibrous: limits intake
Malnutrition examples
Serrated tussockNassella trichotoma
African lovegrassEragrostis curvula
An introduction to pasture quality• Digestibility
• How much of the plant can be utilised
• Related to energy content• See table
Example: Adult angus cow 550kg body weight
Late vegetative to early flowering Cocksfoot (Dactylis glomerata)
Versus
Late vegetative to early flowering African Lovegrass (Eragrostis Curvula)
An introduction to pasture quality
Cocksfoot (Dactylis glomerata)
Digestibility is 70% Energy 9.9 MJ ME/kg DM (see table)
An introduction to pasture quality
Fibre (NDF) is 60% calculated maximum daily intake is 2% bodyweight = 11 kg DM / day
African Lovegrass (Eragrostis curvula)
Digestibility is 50% Energy 6.5 MJ ME/kg DM (see table)
An introduction to pasture quality
Fibre (NDF) is 73% calculated maximum daily intake is 1.65% bodyweight = 9 kg DM / day
Calculating maintenance energy
For more information see NSW Department of Primary Industries’ Managing and Preparing for Drought Guide 2018, and many other useful feeding guides on the NSW DPI website https://www.dpi.nsw.gov.au/ animals-and-livestock/nutrition
Weight of cattle
Energy of feed
Kg per day
“Dry” (Maintenance)6.25kg / day
6 months pregnant (add 20%)7.5kg / day
8 months pregnant (add 40%)8.75kg / day
With a calf (add 60%)10kg / day
In the cold (add 20%) with calf11.25kg / dayWeight loss(cannot eat enough)
Cocksfoot (Dactylis glomerata)
African Lovegrass (Eragrostis curvula) “Dry” (Maintenance)
10.3kg / dayWeight loss(cannot eat enough for maintenance)
6 months pregnant (add 20%)12.36kg / day
8 months pregnant (add 40%)14.4kg / day
With a calf (add 60%)16.5 kg / day
In the cold (add 20%) with calf18.6 kg / day
Malnutrition
• Quality too low to maintain stock body weight
• Animals may not graze it by choice
• Indigestible balls in rumen
Animal health and welfare
Malnutrition example
Serrated tussockNassella trichotoma
• Digestibility 30 – 50%• Energy 4 – 7 MJ ME kg/DM• NDF 85%
Malnutrition example
Serrated tussock (Nassella trichotoma)
Poisonings
• What makes plants poisonous?
• Some plant poisoning syndromes
• Plant poisoning “first aid”
What makes plants poisonous?
• Multifactorial
• Plant factors
• Environmental factors
• Animal factors
There are over 200 plant species in Australia that are potentially toxic to ruminants!
Plant factors• Toxic chemicals (defence mechanisms)
• Palatability
• Stage of growth
• Part of the plant (stems, leaves or flowers)
• Disturbance or stress (see environmental factors)
Environmental factors• Rainfall moisture stress
• High temperatures wilting
• Cold or overcast conditions
• Soil minerals and nutrients (including urine and manure)
• Insects or pathogens
• Fertiliser use
• Herbicide use
Animal factors• Species (ruminant vs non-ruminant)
• Age (detoxification systems, body size)
• Prior learning / novel foods
• Hunger
• Malnutrition
• Confinement / lack of choice
• Tolerance
Drought!
Nitrate toxicity on fodder oats (avena sativa)
Case study
Avena sativaLake George area, 2019
Basic overview of nitrate toxicity
“The perfect storm”
• Sudden death (+/- collapse, breathing problems)
• “Staggers”
• Gastrointestinal (bloat, diarrhoea etc.)
• Photosensitisation
• Chronic and cumulative poisonings
• Bracken poisoning
Some plant poisoning syndromes
Sudden death: Nitrate toxicity
Ruminants
• Organs starved of oxygen
• Rapid breathing
• Weakness
• Lethargy
• Abortions
Sudden death: Nitrate toxicity examples
Cathead / CaltropsTribulusterrestris• Relatively
un-palatable
Wild Radish (Raphanusrapha-nistrum)• palatable
Mintweed(Salvia reflexa)• Relatively
unpalatable• More
palatable as it dies in late autumn / early winter
ThistlesPatersonsCurseEchiumPlantagineum• Relatively
palatable, more after herbicides
• Sudden death (+/- collapse, breathing problems)
• “Staggers”
• Gastrointestinal (bloat, diarrhoea etc.)
• Photosensitisation
• Chronic and cumulative poisonings
• Bracken poisoning
Some plant poisoning syndromes
• Falling with tremors syndrome
• Other neurological or neuromuscular conditions
“Staggers”
Staggers example: “Phalaris staggers”
Phalaris (Phalaris aquatica)
• Multifactorial• Lush new growth• In the morning• High soil nitrogen• High temperatures• Foggy or cloudy weather /
shade• Frost
• Tremors and
weakness
• Worse when forced
to exercise
• Excitable
• Head tremors,
twitching, nodding
• Kneeling,
knuckling
• Falling over
• Problems eating
• (Sudden death)
• Cattle and sheep
• Alpacas (sudden death syndrome)
Staggers example:“Coonabarabran staggers”
Cathead / Caltrops(tribulus terrestris)
• Progressive muscle weakness
• Lean to one side
• Walk on diagonal
• Eventual deathSheep• Eating large
amounts
Staggers example: Sulphur poisoning
Wild radish (Raphanusraphanistrum)
• Stop eating
• Lethargic
• Breathing problems
• Depression / aggression
• Apparent blindness
• Head pressing
• Aimless circling
• Confusion
• (Sudden death)
Ruminants
• Sudden death (+/- collapse, breathing problems)• “Staggers”
• Gastrointestinal
• Photosensitisation• Chronic and cumulative poisonings• Bracken poisoning
Some plant poisoning syndromes
Gastrointestinal example: Steroidal glycoalkaloids
Solanum species• Unripe fruits• Green parts
Herbivores• Hungry
• Severe diarrhoea and colic
• +/- vomiting
• Rarely breathing problems and depressed brain function
• Sudden death (+/- collapse, breathing problems)• “Staggers”• Gastrointestinal
• Photosensitisation
• Chronic and cumulative poisonings• Bracken poisoning
Some plant poisoning syndromes
Photosensitisation
• Primary or secondary• Sensitiser molecules lodge in skin• Activated by sunlight• React and cause inflammation• Unpigmented and unprotected skin affected
• PrimaryPlant pigments
• SecondaryLiver-damaging plant toxins Liver can’t excrete chlorophyll breakdown productsThese lodge in skin as sensitiser molecules
Photosensitisation: Reddened and swollen skin
• Sheep: Ears, eyelids, face, lips, coronets
• Cattle: Teats, udder, escutcheon, muzzle, underside of tongue • +/- Drooping ears, weeping eyes, high temperatures, restlessness and
confusion, incoordination, lameness, abortion
Photosensitisation examples
St Johns WortHypericum perforatum
Primary photosensitisation
Horses > Sheep > Cattle > Goats
• Worst in summer during flowering• Sheep only need ~60g in summer
(versus ~3kg in winter for toxic effect)
• Can use strategic grazing • Use adult Merinos, fine or super-fine, not
pregnant, not lactating, with 4 months of wool growth
Photosensitisation examples
Caltrop / CatheadTribulus terrestris
Mostly ruminants
• Stressed plants more toxic
• Chronic exposure
• Young animals more susceptible Secondary photosensitisation
• Sudden death (+/- collapse, breathing problems)• “Staggers”• Gastrointestinal • Photosensitisation
• Chronic and cumulative poisonings
• Bracken poisoning
Some plant poisoning syndromes
Pyrrolizidine Alkaloids
Toxins damage the liver +/- lungs and kidneys
Pigs > Poultry > Cattle and Horses > Sheep and Goats
Damage builds up over time
Once illness is observed it is permanent and usually fatal
Weeks to months until symptoms appear
Pyrrolizidine Alkaloids symptoms
EmaciationDiarrhoeaYawningCompulsive walkingBlindnessInjury from collisionsHead pressingMsucle tremorsDangerous behaviour
Weight lossDiarrhoeaDangerous behaviourBreathing difficulties
Weight lossDiarrhoeaBehaviour changeBreathing difficulties
“Toxaemic jaundice”Sudden death when stressed • Mustering
Pyrrolizidine alkaloids examples
Paterson’s curse(Salvation Jane)Echium plantagineum
FireweedSeneciomadagascariensis
• Sudden death (+/- collapse, breathing problems)• “Staggers”• Gastrointestinal • Photosensitisation• Chronic and cumulative poisoning
• Bracken poisoning
Some plant poisoning syndromes
Bracken Poisoning
• Extensive bleeding (“bracken poisoning”)
• Eating large amounts over 2 – 4 weeks
• Pale gums and whites of eyes +/- with pinpoint bleeding
• Blood in urine, manure, nasal discharge
• Infections and fever
• Tumours of the urinary bladder
• Eating small amounts over years
• Red urine +/- blood clots
• Progresses to anaemia, weakness, wasting, death
Bracken Poisoning
BrackenPteridium esculentum
• All parts of plant are toxic including underground parts
• Greatest concentration of toxin in young unfurling fronds
• 2 -4 weeks of intake
• Young animals, novel feed, palatable part of plant
• Move livestock slowly and carefully to an area with a different plant species composition
• Minimal stress
• Good quality non-green hay
• Good quality clean water
• Contact your vet or district vet
• Get the diagnosis confirmed
Plant poisoning “first aid”
• Photosensitisation
• Reduce exposure to sunlight• Shed / shade +/- animal sunscreens
• Good quality non-green hay
• Good quality clean water
• Contact your vet or district vet
• Get the diagnosis confirmed
• Vet to determine use of anti-inflammatory or antibiotic treatments
Plant poisoning “first aid”
• Weed seeds and stock• Different diets will affect the passage of seeds
through the gut• Generally will take 3- 4 days but up to 7 days• 10 day quarantine is best practice
• Adherence to sheep wool• Seeds can stay attached to wool for months• Shear before release from quarantine
• Care with bought in feed• Poisonings• New weeds establishing
Biosecurity
Resources and contacts
https://www.dpi.nsw.gov.au/biosecurity/weeds
https://www.olg.nsw.gov.au/local-government-directory
NSW Invasive Plants and Animals Enquiry LineP: 1800 680 244E: [email protected]
Thank you!
Farmers Postcard
Weeds and LivestockLou Baskind BVScDistrict Veterinarian Local Land Services(02) 4842 [email protected]
Images courtesy of
• Australian Wool Testing Authority Ltd. Vegetable Matter in Australian Wool. 2019. https://www.woolwise.com/wp-content/uploads/2017/06/Vegetable-Matter-in-Australian-Wool.pdf
• McKenzie R. Australia's poisonous plants, fungi and cyanobacteria. CSIRO Publishing, Collingwood, Vic., 2012
• Moore J. Furze or Gorse. 2019. http://www.herbiguide.com.au/Photos/Ulexeuro.pdf
• NSW Department of Industry. Managing and Preparing for Drought 2018. Department of Primary Industries, Skills and Regional Development, New South Wales, 2018
• NSW Department of Primary Industries. Prograze Manual Ninth Edition. Department of Primary Industries, Skills and Regional Development, 2017
• NSW Department of Primary Industries. Pinkeye in Cattle https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0017/103904/pinkeye-in-cattle.pdf
• NSW Department of Primary Industries WeedWise. https://weeds.dpi.nsw.gov.au/
• WA Department of Primary Industries and Regional Development. Scabby Mouth in Sheep. https://www.agric.wa.gov.au/livestock-biosecurity/scabby-mouth-sheep
• Walker E. A Case of Photosensitisation Caused by St Johns Wort. Flock & Herd Case Studies 2012. http://www.flockandherd.net.au/sheep/reader/photosensitisation-stjohns-wort.html