Farmers are being warned to be vigilant for nitrates poisoning in livestock by the Department of Agriculture’s animal health surveillance (AHS) programme, as rain returns to some areas of the country following the dry spell.
Nitrates poisoning is caused by excess consumption of nitrates from plants, water or via ingestion of nitrates-containing fertilisers and can lead to death.
A cow can consume a toxic amount of nitrates in as little as one hour and will start to show signs such as weakness and staggering shortly after.
A flush of grass growth after a dry period is noted as a high-risk time for nitrates poisoning.
High levels
High nitrates levels in grass occur when nitrates is taken up by the plant faster than it can be converted into protein.
This can occur during times of low levels of sunlight, dry spells or when temperatures drop as all of these scenarios reduce plant energy levels to convert nitrates into protein.
Low soil pH, high nitrogen levels from white clover, sulfur or phosphorus soil deficiencies and low molybdenum also increase nitrates uptake by plants, the AHS said.
Using high levels of nitrogen fertiliser late in the season can also increase nitrates accumulation in plants, particularly if the pasture is grazed soon after application and before full dry matter response.
However, nitrates levels can get high without using nitrogen fertiliser.
The AHS recommends to talk to your veterinary practitioner about control and prevention methods, if you are concerned about nitrates toxicity in your stock.
