Bad hay days created toxic ergot in wet spring weather

  • Published: Wednesday, June 26, 2019

COLUMBIA, Mo. – Farmers face bad hay days as they mow and rake hay that should’ve been baled in May, not now in the first days of summer.

“Worst hay ever.” That conclusion came from talk by University of Missouri Extension agronomists on their weekly teleconference. Frequent rains, little sunshine and many cool days made haying difficult this spring.

First-cutting hay normally would have been baled and stored weeks ago. Farmers aim to harvest first-cutting grass before seed heads emerge from boot stage. When stems are cut at an early stage, there will be no stems at second cutting.

Hay cut now contains mature seeds and few leaves. Feed quality drops.

“Stems and lack of leaves cuts nutrition,” says Craig Roberts, MU Extension forage specialist.

Recent hay tests showed only 8% to 9% crude protein and 50% TDN (total digestible nutrients). “That may support a dry cow, but not a producing cow or calves,” Roberts said.

There’s more bad news. Many seed heads in this wet year are infected with ergots that add toxin to the hay. “Some hay will be toxic this winter,” Roberts warns.

Ergots make fungal replacements for individual seeds in grass seed heads. Spores enter grass florets. The resulting fungus displaces kernels in seed heads.

Ergots produce alkaloids similar to ergovaline, which makes fescue toxic. The most common grass grown in Missouri is fescue, Roberts says.

Cattle eating ergots will show signs similar to fescue toxicosis. That results in slow gains and lost reproduction. Milk production drops.

Roberts says not just fescue but all prime grasses can be toxic with alkaloids this year. That includes cereal rye, ryegrass and brome. Even timothy seed heads contain ergot replacements of individual tiny seeds.

Ergots appear mostly during wet seasons, and parts of Missouri recorded their wettest spring in history this year. Pat Guinan, MU Extension climatologist, told of heavy rains in broad areas along Highway 36 across northern Missouri and in southwestern Missouri centering on McDonald County.

Ergot causes problems, including death, when eaten by livestock.

The problem: Ergot outbreaks are scattered. “We get reports of ergots mainly in the Ozarks,” Roberts said.

Eldon Cole, MU Extension livestock specialist based in Mount Vernon in southwestern Missouri, saw ergots start forming in early June. “They steadily increased since then,” he said.

Bad hay has other causes, Roberts says. This spring seldom saw three dry days of sunshine in a row. That’s how long it takes to cut, dry and bale hay.

“A lot of hay was baled wet,” Roberts said. To save forage, damp hay wrapped in plastic turns into silage.

But ensiling worsens the ergot problem. Toxins are preserved. The amount of toxin in normal hay falls as it dries in bales. That cuts poison in half by winter feeding time.

Prolonged wet spring weather also affects alfalfa, prime legume hay. “Plants aren’t toxic but may appear nitrogen deficient,” Roberts says. Alfalfa may turn yellow and grow slow.

Alfalfa produces its own nitrogen for growth in root nodules. That lowers need for nitrogen fertilizer. Water-saturated soils do not hold oxygen needed by microbes in the root nodules.

This was to be a year to replenish hay supplies for beef herds. After drought years with low hay growth, producers planned to refill hay sheds.

Now hay production depends on fall regrowth of cool-season grasses.

Regional MU Extension agronomists and livestock specialists are available to help plan fall production.

Writer: Duane Dailey

Media Contact

Craig Roberts
573-882-0481

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