TOXIC weeds have killed significant numbers of ewes in western New South Wales recently, prompting a warning for landholders re-introducing sheep to recent regrowth.
Incidents of sheep deaths from nitrate poisoning, including one case involving 60 ewes, have prompted a warning from Western Local Land Services to landholders in the western region of the state to be vigilant.
One landholder lost more than a quarter of a mob within a day of unloading them onto green feed.
LLS said following decent rainfall over summer and into the start of autumn in parts of the western region, green feed has begun to emerge in a number of areas. While the rain has been happily received by all landholders, it does present some unwelcome risks, such as consumption of toxic weeds, as stock favour the emergence of anything green.
A common scenario is empty stock coming off trucks either into the paddock or into yards where weeds thrive due to uptake of nitrates from urine and faeces, LLS said.
Western Local Land Services district veterinarian, Charlotte Cavanagh, is urging caution from livestock owners, particularly if re-stocking.
If possible, landholders are being urged to feed some hay to fill stock up before releasing them onto the attractive green feed so they cannot gorge. Stock should be monitored closely and any unknown plants should be identified.
“Livestock consuming nitrate containing plants such as Tribulus terrestris (caltrop/yellow vine/cathead) and Portulaca oleracea (pigweed) will show a variety of symptoms dependent on how much of the plant they consume and over what timeframe,” Dr Cavanagh said.
“In some cases, nitrates cause direct irritation to the lining of the gut causing diarrhoea, salivation and abdominal pain.
“Nitrate can also be converted to nitrite in the rumen, which then enters the bloodstream and decreases the animal’s ability to carry oxygen,” she said.
“The outcome is rapid breathing, staggers and in severe cases, death.”
Landholders with questions relating to nitrate poisoning or another animal health matter should contact their nearest Western Local Land Services District Veterinarian:
- Charlotte Cavanagh, Bourke, 0429 773 021 or [email protected]
- Trent McCarthy, Buronga, 0437 822 012 or [email protected]
- Jess van de Weyer, Broken Hill, 0417 556 184 or [email protected]
Contact your nearest Local Land Services office on 1300 795 299.