The year of 1692 was a bad year in the town of Salem, Massachusetts. The previous spring had been warm and rainy, and the main crop of cereal rye had been harvested during the summer and threshed around Thanksgiving. But during the winter of 1692, young girls started to exhibit a strange, convulsive hysteria. The good townspeople of Salem reacted to these frightening behaviors by holding trials – witch trials.
But that was a long time ago. How does 17th century history apply to today’s livestock world? Well, here in Oregon we’re noticing some unusual livestock behaviors and even some occurrences of dry gangrene. In fact, similar reports are coming in from all over the country with increasing frequency. Initially, our campus veterinary lab in Corvallis thought the problem might be ergovaline toxicity from the tall fescue endophyte, a well-known affliction in our area. But then the lab conclusively identified the real culprit: “ergot.” Ergotism is an age-old malady, reminiscent of European stone castles and the narrow streets of medieval Paris. This ancient scourge may be raising its head again, this time in livestock. Although no one today is talking about witches, maybe these two items are related. Hang on. This is a wild ride.
Ergot is a parasitic fungus that infects grasses, particularly small grains, as well as many forage species. The medieval French were a bit fanciful in naming it: the word “ergot” comes from their word meaning “spur.” When the ergot fungus (Claviceps purpurea) infects a grass plant, it grows into the reproductive tiller and destroys the ovary, replacing the plump grain with an ugly black or brown elongated mass (the “sclerotium”). This growth can indeed look like a small spur, but to most of us it looks a lot like rat droppings. The seedhead of an infected plant will show one or more of its grains replaced by these black, spur-like growths. Of the common small grains, rye is the most susceptible to ergot, followed by wheat, barley and triticale (a rye-wheat hybrid). Oats are rarely affected. After the infected plant matures, the sclerotium drops to the ground, ready to infect new plants when the warm spring rains occur the following year.
But if this were the entire story, ergot wouldn’t be worth worrying about, except for its ugly appearance and a slight reduction in grain yield. But the ergot fungus is actually a monster; it produces an array of more than 20 pharmacologically active compounds – alkaloids – that can have devastating effects on animals. These alkaloids are mostly vasoconstrictive, meaning they reduce the diameter of blood vessels. The worst is ergotamine, but the other alkaloids also have varying degrees of vasoconstrictive effects.
Historically, medieval herbalists knew about this effect in a very practical way. They carefully used ergot preparations to prevent bleeding at childbirth and even induce abortions (“carefully” was the operative word here). Today’s doctors use derivatives of these alkaloids to treat migraine headaches. In humans, ergotism causes a number of symptoms: itching, numbness, spasms, muscle cramps, extreme pain and convulsions. People suffering from ergotism often report a crawling sensation under the skin, as if they were being pricked by pins. Also, because of the reduced blood flow to the extremities, ergot alkaloids can cause a dry gangrene, resulting in the loss of fingers, toes, earlobes, and even arms and legs.
In addition, one of the ergot alkaloids, isoergine, structurally resembles lysergic acid diethylamide and has well-known psychoactive effects. You might recognize the name. Lysergic acid diethylamide is LSD. It’s no accident that ergotism in humans has been associated with delusions, hallucinations and strange speech.
What about livestock? Although our animals are notoriously reluctant to fill out medical reports, we know cattle, sheep and other livestock can suffer from ergotism. Their symptoms include excessive salivation, incoordination, extreme excitability, nausea, vomiting, scours, abortions, convulsions and dry gangrene (in the hooves, tails, ears, teats and even limbs).
The ergot fungus secretes a witches’ brew of toxins. Veterinary and medical textbooks usually divide ergotism into two categories: “gangrenous” and “convulsive,” based on the observed symptoms. But in reality, these are different shades of the same spectrum, depending on the specific array of alkaloids produced and absorbed. We really don’t know much about the ergot fungus, but I suspect that the species probably has multiple genetic strains that each produce a different combination of alkaloids (similar to the multiple genetic strains we observe in tall fescue endophyte). In addition, environmental conditions may influence the types and proportions of alkaloids these strains produce. The interaction between fungal genetics and the environment is very complex. The bottom line is: Animals (and humans) may show a wide spectrum of ergotism symptoms based on the actual dosages and different combinations of alkaloids they receive.
If that isn’t enough, here are two disturbing items about ergot and livestock. The first is: Ergotism has no cure. Veterinarians must resort to palliative care; they treat affected animals to minimize discomfort and reduce symptoms. The main practical field recommendation about ergotism is to avoid it. Don’t feed animals grains or feeds contaminated with ergot. Period. Or in a desperate pinch, at least dilute the contaminated grain with enough clean grain to reduce the dose of alkaloids and then hope for the best.
The second item relates to no-till farming. Recall that the mature ergot sclerotia fall to the ground and overwinter in the top layer of the soil. When farmers till the ground for spring planting, their plowing and disking buries the fungus deep enough to destroy it. But today’s agriculture has seen an explosive adaptation of no-till farming, especially for small grains and pasture grasses. While no-till farming indeed reduces erosion and improves soil structure, it simultaneously creates the conditions ideal for the sclerotia. There is no soil turnover, so no burying of last year’s vegetation. No-till farming effectively creates a friendly environment for the ergot fungus to survive and infect the following spring’s crop. And what are we seeing around the country today? Well, our laboratories are reporting more and more cases of ergot contamination, and universities are publishing a growing number of bulletins about it. Not surprising, but somewhat worrisome.
Now some history. During the Middle Ages, the main grain crop for much of Europe was not wheat or corn, it was cereal rye (Secale cereale). As in rye bread – a staple food on the dinner tables in most rural areas. Unfortunately, of all the common small grains, rye is the most susceptible to ergot infection. And sure enough, for centuries, ergotism outbreaks periodically occurred across Europe, generally correlated to ergot-conducive weather conditions during the previous year’s rye crop. During one outbreak in France in 1039, some monks built a hospital specifically to care for the victims. Afterward, they dedicated this hospital to St. Anthony, and ergotism was thereafter known as “St. Anthony’s fire” (“fire” referring to the burning sensation under the skin).
But for centuries, ergotism remained a mystery, a curse that seemed to appear out of nowhere. It wasn’t until 1670 that a very perceptive French physician, a Dr. Thuillier, linked ergotism to the black growths in rye plants. He had noticed that ergotism was not a contagious disease like plague or cholera, and that it did not occur in farmers who ate potatoes rather than rye bread or in wealthy urban folks who ate wheat bread. Until then, people had often observed the black growths in rye plants but assumed the growths were innocuous – you know, just one of those things. But 1670 was a few years before the internet or even a good postal system, so Dr. Thuillier’s conclusions were not widely distributed beyond a small scientific community in Europe.
Which was unfortunate because in the far-flung settlements in the New World, farmers also planted cereal rye and made rye bread, just like they did in the old country. In 1691, the fledgling colony of Massachusetts experienced a warm, wet spring. Farmers planted their rye crop as usual. They harvested the grain in late summer and then, in the autumn, ground that grain into flour. Some months later, in the village of Salem, a few young girls exhibited strange behaviors: convulsive seizures, screaming out blasphemies, odd postures, delirium and complaints that their skin was being pricked.
Massachusetts Puritans were not exactly trained scientists, and in previous years they had hanged a couple of people for witchcraft. During the winter of 1692, faced with behaviors so unusual, so bizarre and otherwise unexplainable, some villagers – including the doctors – accused the girls of witchcraft. One thing led to another – you can read volumes about this historical episode – and during that year, the Salem townspeople conducted a series of trials. By September, they had executed 20 people for witchcraft. Historians have argued at great length about this period and have often postulated that the town was gripped by some sort of mass hysteria.
But given what we know today about rye plants, ergot, vasoconstriction and psychoactive alkaloids, there is another explanation, at least regarding the original behaviors of those young girls: They exhibited the alarming symptoms of ergotism. The subsequent trials and the hysterical actions of the townsfolk, well, those are still juicy topics for historians and legal scholars, but in this month’s article we’ll keep our focus on livestock nutrition and its intriguing side stories.
Which brings us full circle. We should consider this: modern big-tractor agriculture, popular soil conservation programs to reduce soil erosion and improve soil structure, and the ways we feed grain to livestock. Then we should consider some history: the Puritans, rye bread and a small New England village in 1692. The common thread? The ancient scourge of St. Anthony’s fire. Yes, it’s a fascinating story. But perhaps also something we should keep in mind today.
