Ongoing heatwave conditions in southern Queensland mean concerns expressed last month about prussic acid outbreaks among sorghum growers on the Darling Downs remain in place.
Hay marketing group Feed Central said in early January it had been fielding many anxious calls from Darling Downs sorghum growers in the wake of a record-breaking three-week long heatwave.
“All sorghum growers had the same concern, no matter whether the sorghum is baled, wrapped in silage, in a bunker or a standing crop,” quality services coordinator Rachael Williams said at the time.
“Prussic acid or cyanide poisoning commonly occurs when animals, particularly ruminants, consume sorghum that has been under stress.
“The particular stress that sorghum has received over the past weeks is that of unusually high and consistent heat.”
A Feed Central spokeswoman said this week that it remained an issue.
“Our Queensland branch has been swamped with growers coming in with sorghum samples, concerned and then singing praise when they find out the results before they acted on feeding the product.
“We are interested in preventative rather than cure.”
Prussic acid comes in the form of HCN, also known as Cyanogenic Glycosides. The production of HCN occurs mainly during the growth stages of a plant and declines once the plant reached maturity.
Once Cyanide Glycoside / HCN is in the bloodstream of the affected animal it is able to be transported throughout the entire body.
Cyanide inhibits the oxygen utilisation in the cells of the body and hence the animal generally rapidly deteriorates and dies from asphyxiation.
Ms Williams said safe levels of prussic acid in a plant were below 599 ppm, and when levels rose above this, the plant was considered unsafe for grazing.
“If the level is 800 ppm or above then it is considered to be toxic. There is no better way to determine what level of prussic acid is in the sorghum than to have it tested.
“I would highly advise testing to all sorghum growers as it is simply not worth the risk.”
Ms Williams said testing was a simple and cost effective way to determine if the product was safe.
Feed Central received over 30 sorghum samples for prussic acid testing in their Queensland feed testing laboratory based in Toowoomba at the start of January, with many more samples coming in over following weeks.
Sally Gall
Based at Blackall, CW Qld, where I've raised a family, run Merino sheep and beef cattle, and helped develop a region - its history, tourism, education and communications. Get in touch at 0427 575 955 if you've got a story idea for me.
Based at Blackall, CW Qld, where I've raised a family, run Merino sheep and beef cattle, and helped develop a region - its history, tourism, education and communications. Get in touch at 0427 575 955 if you've got a story idea for me.
