Farmers have been warned about the dangers of nitrate poisoning after three cows died in West Gippsland in recent days.
Grant Nielsen from West Gippsland Vet Care said current conditions were conducive to nitrate poisoning, with farmers needing to be aware of what causes the illness and how to identify symptoms of sick animals.
“You tend to see nitrate poising in cattle if they are hungry and going onto new pasture or capeweed that has been sprayed, which increases its palatability,” Dr Nielsen said.
“Farmers need to try and control the intake of new pastures or sprayed capeweed paddocks.
“They can strip graze to minimise the impact or get the grass and capeweed tested to see how high the nitrate levels are.”
With overcast conditions being a precursor to nitrate poisoning, Dr Nielsen said farmers should try to take the weather into account when planning grazing regimes.
“Try to avoid grazing in overcast conditions, which can be tricky,” he said.
“But try to make sure cattle are well fed, having concentrates in the diet so there is plenty of energy in the rumen, which is important.”
Dr Nielsen said animals that are urinating frequently and staggering may be suffering from nitrate poisoning and need immediate veterinary assistance.
“You can have sudden death within an hour of grazing, depending on how toxic it is,” he said.
According to the Dairy Australia website, nitrate is a normal component of plants and is usually converted in the rumen to nitrite which is, in turn, changed to ammonia.
If nitrate levels in plants are higher than usual and/or the conversion of nitrite in the rumen is too slow, nitrate concentrations in the rumen can build up to toxic levels.
Excess nitrate is absorbed into the bloodstream where it binds with haemoglobin and reduces the ability of the blood to carry oxygen.
Nitrate can build up in many plants including pasture species such as rye grass, fodder crops such as millet or brassica, or weeds such as capeweed.
For more information go www.dairyaustralia.com.au and click on the Animal Management tab or contact your local vet.