Warm and wet perfect storm for ergot
If you don't go looking, you won't know you have got it.
Louise Cook
ACambridge dairy farmer has warned landowners to check their paddocks for ergot after she discovered a paddock full of the potentially toxic fungus.
A visitor spotted ergot at Owl Farm during a weekly farm walk. It was 100 per cent luck that it was found, demonstration manager Louise Cook said.
‘‘We found it by accident. We happened to have some visitors during our farm walk and they were rummaging around and spotted it.’’
Ergot resembles a tiny black banana a few millimetres long and grows naturally on the seed head of grain and grass plants throughout New Zealand.
Cook said the risks to livestock were huge. It produced potent alkaloids that upon entering the blood of humans or animals, cut off the blood supply to the limbs, causing coldness to the extremities and eventually gangrene and death. Low levels of toxicity caused the lower legs of cows to go cold and high levels would make it so bad that their blood supply would be cut off. Last year, Southland and Otago farmers had to euthanise 100 cows due to ergot toxicity.
The fungus was also potentially lethal to horses and humans. Ergot was often found in grain crops and the arable industry had thresholds in place to prevent it entering the food chain.
Pasture on the infected paddock was in excellent condition and there was no indication it was carrying the fungus. As many as half a dozen affected plants were found per square metre within the two-hectare paddock, Cook said.
‘‘We found this in significant quantities in one paddock and it was a paddock that we skipped for grazing on January 23.’’
The paddock was to be cut for silage, and Cook believed the hot, wet conditions seen throughout most of February combined with unseasonal grass growth resulted in lots of grass developed seed heads, which created the ideal environment for ergot to grow.
She urged other farmers to check their own paddocks. ‘‘If you don’t go looking, you won’t know you have got it, and we have got a perfect storm this year for people to have found it.
‘‘Go and rummage through your seed head and make sure you don’t have little black bananas on it.’’
It was rare to find the fungus at this time of year because farmers did not usually have paddocks filled with grass with seed heads, she said.
The infected paddock was to be cut for silage. Instead, it would be cut for hay. This allowed staff to isolate, mark and separate the feed and ration it out in small amounts to cows to prevent the herd getting sick. Toxicity levels of the fungus would be laboratory tested. Cook said if a farmer suspected they had the fungus, they should talk to their seed supplier or veterinarian. If the paddock was not being used for silage, she recommended giving it a high top with a lawnmower.
Ergot would fall to the bottom and the paddock could then be lightly grazed. For now, Cook said they would be treating the finding as a worst case scenario until the toxicity levels of the ergot were confirmed.