Page 1001 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

Poisonous Plants of Australia and New Zealand Chapter | 63 933

VetBooks.ir areas where there are better prevailing conditions. not active or have low levels of environmental stimulation
may indiscriminately graze on plants simply due to
This technique was pioneered by the implementation
in the early 1900s of traveling stock routes (TSRs;
boredom.
authorized thoroughfares for the walking of domestic
livestock such as sheep or cattle from one location to
CONCLUDING REMARKS AND FUTURE
another) stretching across northern Australia,
Queensland, and New South Wales to South Australia DIRECTIONS
near the Flinders Ranges and also across New South
Poisonous plants continue to be an important cause of
Wales. TSRs remain an often critical source of feed
financial loss within the livestock industries in Australia.
for livestock during drought conditions. Traveling
Compounding the pure financial losses is the fact that
stock on a TSR must travel 6 miles a day (by law) in
“outbreaks” of plant poisonings are often tied to climatic
order to avoid the grazing off of all fodder within a
conditions, such as droughts and floods, when producers
particular TSR area. However, the use of TSRs under
are focused primarily on maintaining the minimal core
drought conditions is not foolproof and there have
herds of livestock that will allow them to rapidly restock
been many notable large-scale stock losses on TSRs
and take advantage of good climatic and pasture condi-
due to movement of stock into areas where there are
tions when they return. Currently available practical tech-
unfamiliar local poisonous plants. Knowledge of the
niques are partially successful in reducing livestock
likely poisonous plants in different geographical areas
losses, although well-proven techniques such as geo-
remains critical to the success of these methods.
graphic relocation of livestock are economically expen-
Another long-standing and well-proven strategy to
sive and capital intensive.
reduce the risk of stock losses due to the rapid emer-
Historically, the investigation of plant poisoning in the
gence of indigenous poisonous plants following a
Australian and New Zealand livestock industries has gen-
break in a drought is to not allow livestock into a
erally focused on death or severe acute events as key end-
grazing area until safe fodder plants dominate the
points. There is little doubt that within these contexts,
pasture. Again, the ability to geographically relocate
there is still much to learn regarding the poisonous plant
stock into safe areas and hold them there until the
flora of Australia and New Zealand. However, subclinical
pastures return to a good and safe condition, as well
losses (e.g., diminished growth rates rather than outright
as knowledge of the local flora and physical inspec-
stock losses) and the use of indigenous plants as safe
tion of the pastures, is critical to the success of such
sources of fodder (particularly during adverse climatic
a strategy.
conditions) are also likely to be areas of future
Good pasture management is often a key factor in
investigation.
reducing the impact of many poisonous plants. Critical
factors include not overgrazing pastures, not over-
stocking pastures, and pasture spelling/rotation. REFERENCES
Another common problem in Australia has been the
Australian Plants
introduction of toxic weeds into a hitherto clean area.
ABARE, Australian Bureau of Agricultural and Resource Economics,
Effective integrated weed management programs are
2006. Gross value of farm and fisheries production. Aust.
critical to reducing risks of this nature.
Commodities. 13 (2), 438 439.
One of the important animal-related factors that are Covacevich, J., Davie, P., Pearn, J., 1987. Toxic Plants and Animals: A
amenable to human intervention is to ensure that livestock Guide for Australia. Queensland Museum, Brisbane.
are familiar with the local fauna. Large-scale stock losses Dowling, R.M., McKenzie, R.A., 1993. Poisonous Plants: A Field
Guide. Queensland Department of Primary Industries, Brisbane.
that have occurred when naive stock are moved or
Everest, S.L., 1974. Poisonous Plants of Australia. Angus & Robertson,
released into a new geographic area are commonplace in
Sydney.
the history of poisonous plants in Australia. Limited,
Gardner, C.A., 1956. The Toxic Plants of Western Australia. West
staged, and well-controlled introduction of naive livestock
Australian Newspapers, Periodicals Division, Perth.
into a new geographic area may reduce the risk of such House, J., 2007 New South Wales Department of Primary Industry.
events. It is also critical to ensure that the new geographic PRIME FACTS. Scrub Feeding. PRIMEFACT 348.
area has plenty of safe forage and that relevant poisonous Lowry, J.B., 1995. Deciduous trees: a dry season feed resource in
plants do not dominate the edible local flora. Particular Australian tropical woodlands. Trop. Grassl. 29, 13 17.
care should be taken to ensure livestock are not hungry McBarron, E.J., 1983. Poisonous Plants: Handbook for Farmers and
when they are introduced into a new area. Graziers. Inkata Press, Melbourne.
Another animal-related factor that is amenable to Offord, M., 2006. Plants Poisonous to Horses. An Australian Field
human intervention is boredom in horses. Horses that are Guide. Australian Government Rural Industries Research and
Development Corporation, Barton.