Nitrate poisoning killing cows
Waikato sharemilkers Cam and Tessa Hodgson have lost 49 cows to nitrate poisoning, which could cost them up to $73,000.
Nitrate poisoning happens as animals graze, and often occurs after a drought when there are high levels of nitrogen in the soil, and is exacerbated by humid, cloudy conditions.
Cam’s brother Matthew Hodgson has started a givealittle page for them, saying their passion is farming ‘‘and to see the cows die in front of them is heartbreaking to them’’.
The page has so far has received $16,777 in donations. It is due to run until June 20.
He told Fairfax Media the farm was a ‘‘scene of devastation’’ which he would never like to see again.
Signs of cattle being affected are abdominal pain, muscle tremors, drooling of saliva, blue discolouration of the mouth, and collapse before the animals fall into a coma and die.
It can be treated with the medication methylene blue, which is also an antidote to cyanide.
Federated Farmers Waikato provincial president Chris Lewis said nitrate poisoning was relatively common. He himself had lost 10 cows to it several years ago.
The book value of the cows was between $1600-1800 each, but the market value was between $1400-1500 each, he said.
He said he had spoken to Matthew because the couple were too upset to talk to media or himself about the poisoning.
The Hodgsons were grazing brand new annuals and the nitrate levels were ‘‘rocketing along’’ in the humid conditions.
Dairynz says on its website there is a high risk of nitrate poisoning in the autumn, especially when grazing new grass and annuals.
Cool, cloudy days and fast rotations are conditions that favour nitrate poisoning and often occur after severe drought conditions.
The risk of nitrate poisoning can be reduced by:
Grazing pasture that is older than 21 days-long rotation;
Ensuring that the cows are not
❚❚hungry when put onto high risk pastures;
Feeding forage supplement first and restricting the time on high risk pastures.
Stock also need to have access to fresh and clean water.
Nitrate poisoning is a hazard on cool cloudy days, especially in autumn.