ARCHIVE FILE
This article was published in 1984
See the original document
Problems Associated With Paterson's Curse
J.B. Kemp, B.V.Sc., Dip. A.H., M.Sc., Veterinary Inspector, FORBES
INTRODUCTION
The scientific name for Paterson's Curse is Echium plantagineum. (It was previously known as E. lycopsis).
It is an erect winter and spring annual or biennial, up to 1.2 metres high with hairy leaves. The plant at first forms rosettes with broad oval leaves, later forming the stem, with smaller, narrow, heart-shaped, hairy leaves 3 to 9 cm long. The stems arise from a short, stout taproot. The bluish purple (rarely white) flowers are tubular and are 2 to 3cm long and have 5 stamens, 2 of which protrude. The fruit is composed of 4 rough angular grey or brown wrinkled nutlets surrounded by the persistent calyx. Flowering takes place mostly in the spring and early summer and rarely at other times.* This year, it has been seen flowering right through from January in the Forbes District due to the regular summer rain. (* Cunningham et al. 1981).
HABITAT
Paterson's Curse occurs on all soil types but is most common on sands and sandy loams.
ORIGIN
Paterson's Curse originates from the area from the Mediterranean region to Western Europe, including the British Isles.
INTRODUCTION OF PATERSON'S CURSE INTO AUSTRALIA & SPREAD
The first introductions of Paterson's Curse (Echium) into Australia were probably in the 1800s when plants (seeds) were brought intentionally from the British Isles, the Mediterranean region, the Canary Islands, and the Cape region of South Africa to various gardens in Victoria, N.S.W., South Australia and Tasmania.
Deliberate introduction and spread probably were encouraged by the availability of seed for purchase. Accidental introductions also occurred such as in contaminated canary seed and agricultural produce such as fodder. Paterson's Curse in Australia seems to be the species that was most commonly introduced as a garden plant around the 1850s. It was introduced as a garden flower at Cumberoona by a Mr. Paterson in about 1880. Cumberoona is the name of a locality in the Albury Pastures Protection Board District. There is a Travelling Stock Reserve called Cumberoona Reserve, and also a farm by the same name near the Reserve. The Paterson's farm was just out of an old township called Bowna, about 22 miles north-east of Albury. Bowna was flooded when the Hume Weir was built (M. Barry - pers. com.). The Paterson's Curse remained as a small patch on the farm until about 1897, when it spread through a fence onto a travelling stock reserve and quickly became widespread on stock routes, reserves and paddocks throughout the district. Seeds are dispersed by the movement of stock as the seed coat adheres to wool and the seeds have the ability to pass through animals and retain viability. By 1905, it was spreading around Albury and by 1916, it had been reported from the Upper Murray, Bourke, Nyngan, Wilcannia, Dubbo, Hay and Jingellic (Piggin, 1976).
In N.S.W., it is abundant on the central and south-west slopes and adjacent plains, the coastal and mountain regions around Sydney and the A.C.T.
Quoting from the January, 1984 newsletter of the Noxious Plants Advisory Committee of N.S.W. -
'Drought breaking rains began in March, 1983 and continued through the winter and spring and have been ideal for the growth and spread of Paterson's Curse. The lush growth coincided with the end of the worst drought this century and consequently stock numbers were low and many improved pastures denuded. The plant has grown in unprecedented abundance from one end of the State to the other. Heavy infestation of Paterson's Curse has appeared in areas where once the plant was a rarity and the plant is growing as far west as Cobar.'
(See Map of Distribution of Paterson's Curse in N.S.W. - Dellow, 1984).
KEY
Heavy - heavy infestations throughout the majority of properties.
Medium - moderate infestations on a number of properties.
Light - isolated plants scattered throughout the area
Nil - no Paterson's Curse
PATERSON'S CURSE DISTRIBUTION. NEW SOUTH WALES - 1983-84
Paterson's Curse has naturalised in South Australia, Victoria, N.S.W., and the southern parts of Queensland and Western Australia (see map of Australia showing distribution - Piggin, 1976).
From Paterson's Curse (Echium plantagineum) in Victoria by C.M. Piggin - report from Keith Turnbull Research Institute - Vermin and Noxious Destruction Board, Frankston, Victoria, 31 99 June, 1976
Overseas in the native regions, Echium species differ from regions where they have become naturalised. In countries around the Mediterranean and Atlantic coasts of Europe and northern Africa, where they seem to be native, they are all common but rarely abundant on roadsides and in waste areas and pastures.
In countries where they are introduced, the situation seems to be different. In Australia, E. plantagineum is well suited ecologically to grow in the annual pasture areas of southern Australia, while in Europe it is heavily attacked and damaged by a range of insects that do not occur in Australia. (Piggin, 1976).
EXAMPLES OF THE EFFECTS OF PATERSON'S CURSE ON 7 PROPERTIES IN THE FORBES PASTURES PROTECTION DISTRICT
1. RH, EUGOWRA
Situation of property - Eugowra. With timberland hills plus flats.
Area - 1,740 hectares
Stock - 1,775 crossbred ewes (1 to 5 years old), bought in at 12 months of age (Merino-Border Leicester cross).
700 Merino wethers (1% to 3 years old).
100 head breeding cattle (Shorthorns and Santas).
Cropping - 344 hectares (850 acres), wheat and oats.
Pastures - clover (majority Dwalganup, Mara and Wigenellup).
Area affected with Paterson's Curse - 500 acres badly affected, another 500 acres partially affected.
History of spread of Paterson's Curse on the property
Owner has been on property for 23 years. No Paterson's Curse on property 12 years ago. Paterson's Curse originated from road on eastern boundary of property. In cattle paddocks - Paterson's Curse completely dominant, eliminating clover sown 5 years ago. Concern regarding Paterson's Curse getting into timbered hills. In sheep paddocks - Paterson's Curse is kept down allowing other pasture species to grow including clover.
Stock losses on the property
No cattle losses (no horses or pigs run). Paterson's Curse very prolific in spring and summer of 1981 and 1983. In January, 1982 - 15 ewes died from a mob of 350, aged 5 years, grazing Paterson's Curse for 6 to 7 months. In spring and summer of 1983, 55 ewes died (at least 33 jaundiced) and 4 Merino wethers (at least one jaundiced). Post-mortem done on ewe on 30 November 1983 - laboratory confirmation of pyrrolizidine alkaloidosis and elevated liver and kidney copper levels.
Control of Paterson's Curse on the property
1. Merino wethers bought in to control Paterson's Curse. Paterson's Curse problem increased with increased cattle numbers and decreased sheep number. 15 years ago - had 4,000 sheep and 50 to 80 head of cattle. 3 years ago - had 260 head of cattle. Now he has 2,475 sheep. He has had exclusive cattle paddocks which has increased the problem.
2. Sprays Paterson's Curse with 24D in young rosette stage and grazes sheep on it 10 days later.
3. Crops are sprayed with 24D and a broad leaf spray.
4. Ploughing - dried off stage is difficult to plough.
2. CJ, GRENFELL
Situation of property - Henry Lawson Way, Grenfell.
Area - 1,214 hectares.
Stock - 4,500 sheep, breed Merinos and Merino-Romney Marsh cross. 85 cattle (cows and calves), Lincoln Red.
Pastures - clover, perennial rye, and Wimmera rye.
Soil - red loams to granite. Even heavy infestation.
Types - of Paterson's Curse on heavy black soil.
History of spread of Paterson's Curse on property
1954 - no Paterson's Curse on property.
1957 - drought; lot of stock on T.S.R. adjoining property.
1958 - winter and spring; good falls of rain and Paterson's Curse scattered on T.S.R. Paterson's Curse found around trees and along fences (carried by birds?), even on 200 acre paddock at back of property.
Paterson's Curse cut and pulled by owner for 4 years, then out of control.
Stock Losses
No losses in cattle or Merino sheep.
1 horse died 2 years ago from pyrrolizidine alkaloidosis.
20 crossbred ewes died 2 years ago, severely jaundiced.
Grazing on Paterson's Curse during spring.
Control on the property
Cropping - 525 acres cropped (wheat and barley)
Spraying - 24D and 24D Igram, within a month of break of season.
Problem area of Paterson's Curse
160 hectares (77 ha. of which is grazed by cattle - on timbered country).
Rate of spread of Paterson's Curse on the property
1. Takes 4 years from spraying a paddock for Paterson's to 100% establishment.
2. Within a year, paddock can change from moderate infestation to 100% infestation.
Problems of Paterson's Curse on CJ's property
1. Reduced carrying capacity: Heavily infested areas - only 25% carrying capacity compared with clover and ryegrass pasture. Economic loss varies with density of Paterson's Curse.
2. Pinkeye in cattle - at time of drying off of Paterson's Curse. In big Paterson's Curse years up to 20% calves and yearlings, up to 2 to 3% cattle (grown).
3. Skin problems in humans - at dried off stage of Paterson's Curse intense irritation of skin.
4. Nervous signs in cattle - occurs only when Paterson's Curse is in flower, October-early November. Lap tongue around stalk for flowers. Occurs after mustering and yarding. Up to 40% mob affected - mainly older cattle and not calves. Signs of drunkenness, unsteady gait, starey eyed, eyes roll, may charge. Only odd beast with severe symptoms.
3. WC, TRUNDLE
Situation of property - Trundle.
Soil Type - light red loam (2/3 of property), Paterson's Curse a problem.
black soil (1/3 of property), Paterson's Curse not a problem. Area - 644 hectares.
Stock - 450 to 500 Corriedale ewes usually (total 1,000). At present 350 breeding ewes. No cattle.
History of Paterson's Curse on the property
Owner 56 years old, born on the property, and Paterson's Curse has been there for as long as he can remember. Paterson's Curse became a problem after 1973 (losses before only 1 to 2%). From 1974, Paterson's Curse became worse at same time as increasing cattle numbers - reached 50 head, sold in 1978.
Losses from Paterson's Curse
From 1974.- losses became worse. In the good years with bad Paterson's Curse losses reached 10% ewes. Stress triggered the deaths, 2 to 3 days after yarding and usually after shearing. Age of ewes to die - majority in older ewes, 4 tooth on and with lambs sucking them, but deaths have occurred in 2 tooths. An odd Corriedale wether has died. In 1980 - post-mortem was done in a ewe. Typical chronic copper poisoning. Laboratory confirmation of pyrrolizidine alkaloidosis and elevated kidney and liver copper levels.
Control of Paterson's Curse on the property
Cropping - usually 300 hectares are cropped (only 1 paddock not cropped). No spraying is done.
Control of chronic copper poisoning
1. Furney's Molybdenum blocks, started using them in 1978 - have cut mortalities by half.
2. Molybdenised super.
4. MG, FORBES
Area - 850 hectares.
Stock - 1,650 first cross ewes (Border Leicester byMerino). 20 Steers.
Soil Type - light red soil and heavier grey soil along river. Property consists of river flats.
Cropping - barley, oats, wheat and lucerne seed (73hectares under irrigation).
Situation of property - 4 miles west of Forbes.
Paterson's Curse covers the whole property.
Stock Losses
In July, 1982, 5 ewes died over 2 weeks from a mob of 580 crossbred ewes, 3 to 5 years of age. Post-mortem of a ewe showed a jaundiced carcase. The liver was a lighter colour than normal and mottled. Liver and kidney copper levels were excessive (18.2 and 3.4 m moles/kg respectively), and histopathology of the liver was consistent with pyrrolizidine alkaloidosis. (Normal levels - Liver <13.0 m moles/kg, & Kidney <0.5 m moles/kg).
Control of Paterson's Curse on the property.
1. Spraying of wheat crops with 24D amine (65 hectares were sprayed last year).
2. Cultivation - an extra working is required because of Paterson's Curse.
Other problems with Paterson's Curse on the property
1. Decreased grazing. In a 100 acre paddock, which has not been cropped for 10 years, is 100% dominant with Paterson's Curse in the spring. Sheep are only on it during the young stage. In the winter it has clover (Dwalganup).
2. Competition for bees. During flowering of Paterson's Curse, the bees prefer the Paterson's Curse to lucerne flower. Therefore, Paterson's Curse competes for pollination by the bees.
Use of Molybdenum blocks - none used.
Mortalities since July 1982 - no more deaths due to jaundice have been recorded.
5. GS, FORBES
Situation of property - between Forbes and Grenfell.
Area - 2,000 hectares.
Stock - 4,500 Merino sheep.14 cattle.
Soil Type - red and brown loam, Paterson's Curse prefers lighter red loam (none on heavier red country on flats).
History of spread of Paterson's Curse on the property
The owner first noticed Paterson's Curse about 25 years ago when the New Grenfell Road was put through. He believes it was spread by the graders when forming the road. Very little stock uses the road.
The owner believes the Paterson's Curse was spread onto his property by flooding as it affects mainly the area on the western side of the road consisting of 200 hectares which lies in the direction of flow of flood waters from the hills.
Stock losses
There have been no losses from jaundice, that is known.
Problems caused by Paterson's Curse on this property
1. Allergic problems.
(a) younger son unable to work on the property due to hives and asthma.
(b) wife suffers from chronic hay fever.
(c) a workman suffers from chronic hay fever - require injections.
2. Harbour for red legged earth mite.
3. Problem in wheat crops.
Control
Ploughs it just before flowering. Doesn't spray.
6. JH, GRENFELL
Situation - Henry Lawson Way, Grenfell.
Area - 188 hectares.
Soil type- granite loam.
Paterson's Curse on the property - 100% coverage.
History of Paterson's Curse on the property
In 1969 - there was very little Paterson's Curse on the property. From 1969 to 1976 - only cattle were run on the property and this was the time when Paterson's Curse became a problem.
Stock Losses
In December, 1978, five first cross ewes and 1 Dorset ram died over a week. They had been grazing on Paterson's Curse. Post-mortem of the ram showed marked jaundice. Tissues were not fresh and so were unsuitable for histopathology. Liver and kidney copper levels were excessive (1982.2 and 161.8 ppm respectively). Number in mob was 377 first cross ewes.
Control of chronic copper poisoning
The owner put out Molybdenum blocks (3 at a time) and had no further deaths.
Control of Paterson's Curse
In 1983, (a very bad year for Paterson's Curse) the whole property was sprayed using 24D amine at the rate of ½ pint per acre. The right time of application is critical - when it is growing strongly, shortly after rain. He applies it, depending on the rain, any time from mid March to end of April. A contractor did it at a cost of 53 cents per acre for spray and 70 cents per acre for application.
7. FB, TRUNDLE
Area of property - 2,126 hectares.
Number of sheep (June 1981) - 2,410 (consisting of 1,060 Border Leicesters and 1,350 Merinos).
Location of property - Trundle.
Deaths from pyrrolizidine alkaloidosis
In June, 1981, a post-mortem was done and the carcase showed severe jaundice, black kidneys, and haemorrhagic enteritis. Liver copper level was very high (1900 ppm) and kidney was 81 ppm. Histopathology was consistent with pyrrolizidine alkaloidosis with megalocytosis of the hepatic parenchymal cells. (There was also universal moderate portal fibrosis.)
30 Border Leicester ewes died over several weeks, most being severely jaundiced. The sheep were mostly found dead but some took a couple of days to die. There was a history of grazing on Paterson's Curse, Heliotrope and clover.
The age of the sheep to die was 6 tooth to full mouth.
Treatment
1. The owner drenched the sheep with a Molybdenum drench.
2. Molybdenum blocks were put out at the rate of 1 block per 100 ewes and 1 block per 50 weaners.
Control of Paterson's Curse on the property
1. Cultivation - all the farm is arable and so all of it comes under cultivation every 3 years.
2. No sprays are used.
Position as at March, 1984
There have been no more mortalities from copper poisoning. The Border Leicesters are still given Molybdenum blocks. Number of Border Leicesters have been reduced from 600 ewes to 100 (now rising 4 tooth) and he keeps these away specifically from the Paterson's Curse. He also runs 1,000 Merino ewes.
PATERSON'S CURSE TRIAL AT REGIONAL VETERINARY LABORATORY, ORANGE
This trial is being undertaken by John Seaman at the Regional Veterinary Laboratory at Orange. The aim is to investigate the role of Paterson's Curse in the chronic copper poisoning syndrome of sheep and to assess the toxic effects of continual grazing of the Curse.
A group of 23 adult crossbred ewes were placed on a paddock of 5 acres at Cadia which had a total ground cover of over 80% Paterson's Curse throughout the paddock. A control group of 21 ewes were placed on an 8 acre paddock which was virtually free of the Curse. The Paterson's Curse was the first plant to germinate following the rain. The trial started in June 1983. Up to February 1984, there had been no deaths in the. Paterson's Curse group. However, there was a production difference of 8 kg average liveweight gain between the groups which is significant. Histological evidence showed progressive liver damage in a number of sheep in the Paterson's Curse group which suggests the grazing of the plant is having a toxic effect, despite the absence of mortalities. (Seaman 1984).
MARGINAL TOXIC EFFECTS DUE TO PATERSON'S CURSE IN MERINO WETHERS FROM LONG TERM FEEDING
Culvenor et al. (1984) fed groups of 10 Merino wethers in pens with pelleted diets containing 80 and 20% Echium plantagineum for 4 periods of 12 weeks alternating with 4 similar periods on control diet. Mild liver damage characteristic of pyrrolizidine alkaloid poisoning, was induced in one wether consuming 80% Paterson's Curse (E. plantagineum). The other animals on the 80% diet showed only a small increase in the size of the hepatocytes which was not unequivocally due to alkaloids. There were no effects on liver function, serum enzymes, weight gain or wool growth attributable to alkaloids. In the 80 and 20% Echium diets, approximately 1/4 to 1/3 of the alkaloid of the fresh plant was lost during diet preparation and storage. Echium feeding induced a high rate of destruction of pyrrolizidine alkaloids in the sheep rumen.
BIOLOGICAL CONTROL OF PATERSON'S CURSE
About 4 years ago the CSIRO had, through its Division of Entomology, tested a range of organisms considered suitable for the biological control of Paterson's Curse. Excellent progress was made with 2 insects in particular, a stem boring beetle and a leaf mining moth. Three releases of the moth were made in N.S.W. in 1980 to test survival and possible establishment. At about the time that the CSIRO made its first releases, 2 landholders, one from the Bathurst district and one from South Australia, and 2 beekeepers from Victoria, sought and obtained a High Court injunction restraining the CSIRO from releasing the control organisms. The proposed spring releases did not eventuate and surviving insects from the test releases were destroyed.
Legislation and Biological Control
In October 1983, the Minister for Primary Industry, Mr. John Kerin, announced that legislation on biological controls was being prepared which would include provisions for the control of such weeds as Paterson's Curse; and that the Australian Agricultural Council had endorsed the preparation of complementary Commonwealth and State legislation to cover biological control programmes. The legislation would allow for a public enquiry process where necessary. It would also provide authority to release biological control agents and a method for the Commonwealth and States to reach agreement about biological control proposals through the Australian Agricultural Council.
Controversy over Biological Control in Australia
(Delfosse & Allen, 1980)
Paterson's Curse above all others in Australia represents an extremely strong conflict of interest between different groups. Some of the arguments are as follows -
(1)Alleged beneficial aspects
1. Particularly in dry seasons in grazing country with relatively low rainfall (300 to 350 mm pa), Echium remains green longer than other plants in spring and early summer, providing valuable grazing when there is little else available.
2. Echium is economically important to the honey industry for 2 main reasons.
(a) it produces a large amount of light honey for export and for blending with darker honeys, and
(b) the production of pollen in late winter and early spring allows bee populations to be built up in time for major honey flows and crop pollination in mid and late spring.
(2) Detrimental aspects
1. The pyrrolizidine alkaloids in Echium causing liver damage in grazing animals and predisposes to chronic copper poisoning.
2. The weed decreases pasture productivity in higher rainfall areas (400 mm pa) by smothering useful pasture species such as sub-clover when the weed is in the rosette stage, and also by leaving only loose soil when it dries off in summer. Also cattle avoid the plant and therefore part of the pasture is non-productive.
SPECIES SUSCEPTIBILITY TO PYRROLIZIDINE ALKALOIDS
Pigs are the most susceptible species of the domestic animals to Pyrrolizidine alkaloidosis. The ratios of increasing resistance are:- pigs 1, poultry 5, cattle and horses 14 and sheep and goats 150 (A.A. Seawright, 1982).
THE ALKALOIDS OF PATERSON'S CURSE
Culvenor (1956) found Paterson's Curse to contain 2 alkaloids - echiumine and echimidine, but the content was found to vary widely from place to place and from year to year. The liver lesion was undistinguishable from that of Heliotropium hepatosis.
In sheep sublethal effects may lead to chronic ill health which may be ill-defined. An altered copper metabolism may lead to death from the haemolytic crisis of chronic copper poisoning.
The chronicity of the disease in sheep or its absence, appears to be due to the considerable destruction of the alkaloids in the rumen (Bull, 1961).
HISTOPATHOLOGY (Bull, 1961)
In the chronic lesion, the centrilobular hepatocytes seem to remain unaffected for some time, whereas those in the mid-zone and periphery of the lobule show characteristic enlargement of the nucleus and the whole cell, i.e. megalocytosis. Megalocytosis is the pathognomonic microscopic lesion of pyrrolizidine, hepatosis. The megalocytes have a higher death rate, and so atrophy of the liver develops and an attempt is made to replace lost tissue by new bile duct formation. In sheep, fibrosis is only slight, but in cattle it is pronounced but not as pronounced as in horses.
Pyrrolizidine alkaloids cause an inhibition of mitosis which results in megalocytosis of the liver cells. The chronic damage to the hepatocytes results in an increased uptake and accumulation of copper as the normal excretion of copper in the bile is depressed.
Unfavourable conditions, such as stress, can cause a sudden release of copper into the blood. The increased blood copper causes destruction of red blood cells (haemolysis) which results in haemoglobinaemia and haemoglobinuria. The urine becomes a red brown colour to almost black and the kidneys become enlarged and dark coloured. There is liver necrosis and jaundice of the carcass.
PATERSON'S CURSE POISONING IN SHEEP IN THE FORBES PASTURES PROTECTION DISTRICT
According to Veterinary Inspector, Forbes' office records, there were 21 cases of Paterson's Curse poisoning in sheep from 1974 to 1983.* These consisted of either reports by the owners or post-mortems. 6 of these flocks were Merinos and the rest crossbreds. Total number of deaths was 271 sheep. Ages ranged from 2 tooth sheep to aged sheep.
* due to pyrrolizidine alkaloidosis.
VETERINARY INSPECTOR, MOLONG - Deaths in sheep following grazing of Paterson's Curse
Veterinary Inspector, Molong, recorded 862 deaths out of 12,387 crossbreds on 13 properties, and 179 deaths out of 6,950 Merinos on 5 properties from October to December, 1983. One property alone experienced 500 deaths out of 3,000 first cross ewes.
VETERINARY INSPECTOR, CARCOAR
Veterinary Inspector, Carcoar, recorded 169 deaths out of 4,173 crossbred ewes on 10 properties after grazing Paterson's Curse. The deaths occurred during the period from October 1983 to January 1984.
PATERSON'S CURSE & NITRATE POISONING IN SHEEP
Between April and June, 1983, 2,412 sheep and 2 cattle are recorded as having died in the Forbes Pastures Protection District from Nitrate poisoning. These stock died on pasture predominantly consisting of Paterson's Curse and Capeweed, both of which reacted strongly to the nitrate test.
One mortality consisted of 172 Merino wethers out of a mob of 1,300 and another of 2,043 Merinos out of a mob of 4,700. Both of these mortalities occurred after the sheep had been locked up. The 2,043 sheep died after having been locked up for 3 nights and 2 days and then let out hungry on the stock route.
CONTROL OF CHRONIC COPPER POISONING
1. Molybdenum blocks. There are at least 3 firms that make molybdenum blocks, namely -
(a) Furney's:
| Analysis | |
|---|---|
| Max. salt | 70.000% |
| Min. lime | 13.000% |
| Min. sulphur | 1.000% |
| Min. sodium molybdate | 0.260% |
| Min. sodium sulphate | 3.750% |
(b) Olsson
(c) Roche-Maag
2. Molybdenum supplementation of superphosphate at the rate of 4 oz. Mo/acre (280 g/ha) has been recommended in southern Australia (Anon 1956) and lime supplementation in addition has the effect of raising the molybdenum concentration in plants without altering their copper status (Rooney et al. 1977).
Copper taken into the animal by the oral route is absorbed from the alimentary tract, stored in the liver and excreted mostly in the bile. In ruminants the amount of copper absorbed and stored is controlled by the amount of molybdenum and sulphate in the diet. (Dick 1953).
3. L.B. Cobbin (1978) recommends for chronic copper poisoning - between 50 and 500 mg ammonium molybdate, plus 0.3 - 1.0g sodium sulphate in 20ml water by mouth according to size. Cobbin states that this depletes liver stores continuously over a fairly lengthy period after chronic accumulation has occurred.
4. My recommendations have been 100mg ammonium molybdate, 500mg sodium sulphate in 10cc water. Give 2 doses over a week. If mustering a problem, then 2 doses on consecutive days (Ian Gardner pers. com. 10/2/82). Blood, Henderson & Radostits (1979) recommend a 3 daily treatment.
5. Clifton's Molybdenum drench (prescription required) - contains 50gm sodium molybdate, 250gm magnesium sulphate per 5 litres. Dose 20ml (i.e. 200mg sodium molybdate).
6. Molytrac (Phosyn Chemicals Ltd.) supplied by Clifton's Rural Products Pty. Ltd., Orange. This is a new product out which is used for spraying directly onto pastures such as clovers.
Excessive molybdenum levels can produce copper deficiencies.
The simultaneous feeding of molybdate and sulphate to single-stomached animals does not have any influence on their body copper status (Seawright 1982).
7. Medicated Salt Licks - Blood, Henderson & Radostits (1979) recommend a mixture of 190 lb salt, 140 lb finely ground gypsum and 1 lb sodium molybdate. Hungerford (1975) dissolves the sodium molybdate in 2 gallons of water and sprinkles it on the salt mixture.
CONCLUSIONS
Paterson's Curse is an example of an introduced garden plant from overseas in the 1800s, and spreading from this habitat to virtually the whole of the State of N.S.W., having a particularly high distribution in the central and southern slopes and plains. Paterson's Curse has also naturalised in Victoria, South Australia and southern parts of Queensland and Western Australia. Herbarium specimens have also been collected in the Northern Territory and Tasmania.
The biological control of Paterson's Curse is controversial, and two beekeepers and two landholders obtained a High Court injunction restraining the CSIRO from releasing the control organism. However, there is ample evidence of Paterson's Curse causing mortalities in stock in the Regional Veterinary Office Central West area. One mortality alone in October-November 1983, in the Molong Pastures Protection Board District, involved nearly 500 first cross ewes out of a total of 3,000. There are also numerous reports of mortalities in horses. Seaman reported the death of 14 horses on 5 properties in the central west of N.Ş.W. during the spring summer of 1976-77. Pigs are particularly susceptible to pyrrolizidine alkaloidosis and mortalities are experienced when pigs graze Paterson's Curse.
Besides mortalities, Paterson's Curse can also be responsible for production losses. In a trial undertaken by Seaman in 1983-84, a production difference of 8 kg average liveweight gain was recorded between two groups of crossbred ewes.
Examples of other problems caused by Paterson's Curse are:- reduction of stocking rate and smothering of useful pasture species when the weed is in the rosette stage; intense skin irritation to people during the dried off stage; allergic problems in humans; competition with lucerne for bees when Paterson's Curse is in flower; having a high nitrate content at certain times and so having the potential of causing nitrate poisoning in stock; and increasing costs of cropping by the need for sprays and extra cultivation.
ACKNOWLEDGEMENTS
Grateful acknowledgements are made to -
1. Mr. John Seaman of the Regional Veterinary Laboratory, Orange for his assistance with references and information on the trial of sheep grazing Paterson's Curse.
2. Mr. J.J. Dellow, Special Agronomist (Weeds), Orange, for his map of distribution of Paterson's Curse in N.S.W.
3. Mr. Don Thompson, Regional Veterinary Officer, Orange for information on mortalities due to Paterson's Curse in the Molong and Carcoar Pastures Protection Districts.
REFERENCES
Anon. (1956) - Aust. Vet. J. 32 : 229-236
Barry, M.R., Veterinary Inspector, Albury (1984) pers. com.
Blood, Henderson & Radostits (1979) - Veterinary Medicine p 960
Bull, L.B. (1961) - Aust. Vet. J. 37 : 126
Cobbin, L.B. (1978) - Proceedings No. 39, Vol. 1 The Therepeutic Jungle - Post. Grad. Com. in Vet. Science, p 327
Culvenor, C.C.J. (1956) - Aust. J. Chem. 9 : 512
Culvenor, C.C.J.; Jago, M.V.; Petersen, J.E.; Smith, L.W.; Payne, A.L.; Campbell, D.G.; Edgar, J.A.; and Frahn, J.L. (1984) - Aust. J. Agric. Res. to be published soon
Cunningham, G.M.; Mulham, W.E.; Milthorpe, P.L.; and Leigh, J.H. (1981) - Plants of Western New South Wales, p 561
Delfose, E.S., and Cullen, J.M. (1980) - Proc. V. Int. Symp. Biol. Contr. Weeds, Brisbane, Aust., 563-74
Dick, A.T. (+953) - Aust. Vet. J. 29 : 233-239
Green, P.S. (1962) - Veterinary Inspector p 87, 88 See www.flockandherd.net.au
Hungerford (1975) - Diseases of Livestock p 41
McBarron, E.J. (1976) - Animal Health in Australia, Vol. 2, Chemical & Plant Poison, p 85-92 and p 157-161
McBarron, E.J. (1978) - Poisonous Plants of N.S.W. p 49
Piggin, C.M. (1976) - Paterson's Curse (Echium plantagineum) in Victoria - report from Keith Turnbull, Research Institute, Vermin & Noxious Destruction Board, Frankston,Victoria
Rooney, D.R.; Uren, N.C.; and Leaver, D.D. (1977) - Aust. Vet. J. 53 : 9-16
Seaman, J.T. (1978) - Aust. Vet. J. 54 : 150
Seaman, J.T. (1984) - Animal Health Project - Region 4, N.S.W. Dept. of Ag. - Progress Report, Feb. 1984
Seawright, A.A. (1982) - Animal Health in Australia, Vol. 2 Chemical & Plant Poisons, p 85-92 and 157-161
Sharrock, A.G. (1969) - Aust. Vet. J. 45 : 388
Other useful References
Parsons, W.T. (1973) - Noxious Weeds of Victoria p 32-36
Dept. of Ag. of N.S.W. - Agfacts
1. Seaman (1983) - Paterson's Curse Poisoning, Agdex 400/657
2. Gill, P.A. (1983) - Pyrrolizidine alkaloid poisoning of sheep, Agdex 430/657
3. Gill, P.A. (1983) - Chronic Copper Poisoning of Sheep, Agdex 430/657