by Deborah Jeanne Sergeant
GENEVA, NY — What’s lurking in your forages? Hopefully not mycotoxins, invisible chemical compounds produced by certain mold species that are harmful and even fatal for the animals that eat it.
John Winchell, representative from Alltech, spoke on the insidious pathogens at the recent New York Certified Organic Meeting. Winchell explained that fungi originating in the soil and on ground debris can be transported through wind, rain or insect dispersal to living plants and contaminate them in various parts of the plants. Later, the animals consuming them can experience health issues.
Developing mycotoxins in forage is easier than one might think.
Winchell’s background in dairying and dairy nutrition, along with selling seed corn and alfalfa, has made him familiar with issues that arise from forage. As he began his talk before a group of about 30, he showed a slide depicting a herd of cows walking on top of — and eating from — an uncovered bunk silo.
“What’s wrong with this picture?” he asked.
The “bunk grazing,” as he jokingly called it, raises the risk for contaminating the cows’ food considerably.
He snapped the photo after spotting the unfortunate herd from the highway. It was worth doubling back to find the farm and capture photographic evidence that this is how some operators farm, allowing their herd to trample and eliminate on the forage provided to them.
“I don’t want cows doing their business on their silage,” he said. “I wouldn’t want to eat out of it.”
Pastured herds experience plenty of room for grazing and elimination; however, in the lot shown in the photo, the animals had little choice but to walk all over their meals.
Winchell said what he has learned about mycotoxins has caused him to wear gloves when he’s handling feed on farms he visits.
“What we feed animals makes a difference,” he said.
He said when he began learning about mycotoxins, he felt shocked how different mycotoxins predominate in different geographic areas. In the Northeast, recent unpredictable weather patterns, such as wet, cool springs and lack of sun all season have increased mycotoxin activity.
He showed photos of bunk silos side by side with infrared images that depicted hot spots, indicating mycotoxin presence. He said more than 400 types of mycotoxins can linger and grow in forage. Since they’re invisible, operators may not know that the forage they’re storing contains enough mycotoxins to reduce production and sicken their animals, or even kill them.
The main families of mycotoxins include Aspergillus toxins, Aflatoxins, Ochratoxins, Tricothecenes A, Trichotheceres B, Zeralenone, Fumonisins, and Penicillium.
Wet weather encourages mycotoxin growth because it encourages Penicillium to flourish. Like an antibiotic, it kills both beneficial and non-beneficial bacteria so that forage can’t ferment properly.
Winchell recalled a case in which a dairy was cited for using antibiotics because of a “hot tank” that didn’t pass inspection. The farmer remained adamant that he used no antibiotics. The culprit was forage with a high percentage of Penicillium, which mimicked the effects of antibiotics.
More problems form when more than one mycotoxin comes to the dance.
“Allowing for interactions among mycotoxins can lead to synergistic or additive effects on the animal,” he said.
He added that high moisture corn has “a lot of mass mycotoxins.”
When treated properly, addressing a mycotoxin exposure can take about 45 days. After the initial insult, it may take three to five days to manifest an internal reaction, such as gut discomfort. By day 8 to 10, the animal exhibits external reactions. It may seem “off” its feed, hold its ears down and appear ill. By day 10, a manager may notice the drooping animal. In a day or two when the vet or nutritionist comes to visit, the animal receives a diagnosis. On day 14, a sample of the fodder is taken for testing to indicate exactly what in it has caused the problem. In about a week, the results come back. At about 22 to 30 days, the remediation begins. By day 45, the situation has resolved.
Without thorough lab testing, operators may not correctly identify the issue, leading to the animal’s lower production, acute illness, and possibly death.
He said when animals ingest mycotoxins, they experience increased stress, altered brain neurotransmitters, reduced nutrition, antibiotic effect on rumen microflora, suppression of immunity, estrogenic effects of zearalenone, cellular death and systemic toxicity.
As with diseases among humans, very young, very old and otherwise less healthy animals are more prone to the effects of mycotoxins.
“Conditions that magnify a mycotoxin problem include stress due to environment, overcrowding or comfort; disease challenge, diet and stray voltage,” Winchell said.
Unfortunately, operators may let it go for so long that animals don’t receive prompt care.
“Mycotoxins are usually the last thing we look at,” Winchell said. “The tests you can run in 10 minutes at the farm.”
The forage with the highest likelihood for mycotoxins include corn gluten, cottonseed, and distillers grains. Winchell has also noticed more small grains contaminated with mycotoxins.
He said producers don’t need to necessarily eliminate these sources of forage in their feeding program, but make sure that the feed is not largely comprised of these.
Sometimes, a good deal turns out to be a raw deal. Winchell recalled a producer whose herd suffered devastating illness after switching to a less expensive type of bedding material. Though the forage remained the same, breathing mycotoxins shed by their peanut shell bedding sickened the animals. The “bargain” bedding proved very costly in subsequent vet bills, time, and reduced production.
In otherwise healthy cows, Pennicillium reduces the positive effects of naturally occurring gut bacteria, which ordinarily eliminates one-third of Vomotoxins.
“This is what I’m seeing this year,” Winchell said.
Unfortunately for producers, too much of seemingly anything affecting their farms — moisture, humidity, heat, oxygen or organic matter — can produce fungal growth that forms mycotoxins.
Risk factors for mycotoxins also include growing corn after corn, no-till practices, soil nutrient imbalance, hail, planting too early or late, pest damage, weeds and improper storage.
Mitigation products can help reduce risk of mycotoxins, as can proper forage handling and storage.