North Island farmers already battling the low payout have been dealt a further blow as they struggle with one of the worst facial eczema seasons in years.
The wet, muggy late-summer weather has created ideal growing conditions for the fungus pithomyces chartarum, which has seen skyrocketing FE-producing spore counts.
These spores live in dead plant matter and produce a toxin that attacks the liver of cattle and sheep when eaten. In the last month, AsureQuality’s weekly spore count monitoring recorded a spike of 2.5 million spores per gram in Matamata, 2.2 million in Hamilton, just under 1 million for Morrinsville and 500,000 spores in Piako, Waipa and Hauraki Plains.
Elsewhere in the North Island, spore counts have exceeded 500,000 in Taranaki, Bay of Plenty and Northland. One location in Taranaki recorded a spore count last month of 1,240,000.
The threshold for farmers to take preventative action against FE occurs when 20,000 spores are detected.
“It’s certainly been one of the worst years in the North Island that I can remember with the spore counts being so high for so long,” AsureQuality FE spokesman Leo Cooney said.
The El Nino weather pattern this summer had caused a prolonged period of extremely high spore counts.
“The warmer soil temperatures and high humidity in different areas too and the warm northerly rains, they have all combined to bring about this danger period that we have had.”
Niwa’s latest climate outlook predicted a warmer April-June which could see high spore counts continue until soil temperatures begin to cool to around 15-16 degrees.
Facial eczema is estimated to cost the country around $200 million annually with affected stock suffering liver and skin damage, reducing fertility, reduced milk and meat production and, if left unprotected, death.
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Clinical cases of FE occur when there are visible signs of the disease, such as skin damage. Sub-clinical cases occur when animals are affected, but do not show visible signs.
This was the disease’s hidden cost, Cooney said, because it often was not detected until pregnancy scanning and calving or lambing when the animal was under stress.
“This is one of the problems with facial eczema. It doesn’t always hit each year and some years are worse than others and once every 10 years you get a really bad season and this is one of them,” he said.
Anexa FVC Matamata veterinarian Finley Koolhoven said this had been one of the worst year for facial eczema he had ever seen.
In March alone, his clinic dealt with 56 clinical cases of FE in the Matamata district, compared to 17 in 2015.
“This is just the tip of the iceberg,” he said.
The worst case he saw so far this season was a mob of 49 bull calves where 39 calves became FE clinical and nine died, despite immediate treatment.
When an animal was FE clinical, it was highly likely most of the other animals in the herd had ingested a similar intake of spores but were not showing symptoms.
Those sub-clinical animals were likely to show the effects of FE in the new dairy season, depending on how badly its liver was damaged.
“Considering there are such high levels of FE this year, the liver damage will be bigger as well, so you can expect a lot of casualties around calving.”
High demand for zinc treatments from farmers meant most vet clinics and retail stores had sold out of boluses, zinc oxide and FE creams, he said.
Farmers were trying to manage the situation as well as they could with their limited budgets. However, there was little they could do when the spore counts reached the millions.
“I’ve seen a few cases where the zinc levels have been at the maximum level of where they should be and there’s still been massive liver damage.”
Tahuna farmer dairy farmer Aaron Price said about 12 cows across the three farms he sharemilks were clinically affected with FE. Leyton Evans, who manages a dairy farm just north of Hamilton, said his herd had five cases.
“I’ve heard that everybody’s got some,” Price said.
Price added zinc sulphate to stock water and zinc oxide in maize feed as soon as spore counts lifted and while there was an economic cost in treating the cattle, it was the hidden costs in the loss of production that affected farmers.
It was another issue for farmers to contend with during what was already a tough season due to the low payout.
“It is what it is. There’s limited control with what we can do. It’s a bit like the payout – you’ve just got to accept it.”
King Country drystock farmer and veterinarian Anna Nelson said she had heard of clinical cases of FE in the past few weeks in her district.
“In the last two weeks there have been quite a lot of clinical cases coming through. Taranaki sounds worse. There’s a very, very serious problem there.”
Tirau sharemilker Peter Butler said FE was detected in 12 of his cows this season. These cows were dried off and taken care of to allow them to recover.
“This year has been particularly bad because of the growth we have got and pasture cover we have got on the farm. It’s super hard just to avoid it.”
“You try and minimise its damage and do what you can.
“When you’re getting spore counts in the millions, there’s not a lot you can do about it.”
CRV Ambreed’s research and development manager Phil Beatson said the Grey Valley on the West Coast had severe outbreaks for the first time, and this year was the worst for several years throughout the North Island, indicating what the future may hold with global warming.
“For every three in 100 cows with clinical FE, it is estimated up to 70 per cent of the herd may have subclinical symptoms. You won’t necessarily see the disease in cows with subclinical symptoms, but it will be damaging the liver and negatively impacting milk production,” Beatson said.
New Plymouth Veterinary Group vet Ross Gadsby said although counts had dropped a little since the beginning of the month, they were still horrendous.
There had been a significant number of clinical cases of facial eczema, as high as 10 per cent of animals in some large herds, and farmers would be losing stock to the disease. “So that’s another thing for them to worry about.
“They don’t like having sick stock. It’s very hard on them,” he said. “There’s a lot of uncomfortable cows out there.”
Gadsby said spore counts in the 40,000 to 60,000 range created a moderate risk of animals contracting facial eczema. Counts above 100,000 were dangerous to stock.
Animals’ exposure to the fungus was significant this season, despite all that farmers had done to protect their animals from the disease.
“It’s a nasty season, with spore counts the highest they’ve been in at least five years. Spraying pasture won’t make much difference when counts are at these levels.”
By: Gerald Piddock & Sue O’Dowd
Source: NZFarmer.co.nz
