COLUMBUS, Ohio – Acorns, cherries and walnuts are just a few of the trees that ripen in the summer and late fall. While most fruit is great for human consumption, the same cannot be said for livestock. In fact, many fruits (and yes, nuts are fruit) can be harmful if not fatal to livestock.

Livestock safety is the number one priority for any farm owner. While most producers think of providing healthy food or preventing dangerous bacteria, trees are not typically high on the list of considerations. However, since fall is the time most trees shed their fruits, there are some much needed precautions to be taken.

Tops on the list and a tree that dots most rural landscapes is the oak tree. Acorns, the product of oak trees, are edible for humans. They are considered unsafe due to their tannins, which are toxic if consumed in high amounts. However, one can remove the tannins by boiling or soaking them. They are great roasted or can be ground into flour. These nuts can be beneficial for human use, but acorns are extremely dangerous to livestock.

“Acorn poisoning can be a significant issue for producers, especially in feeder calves that are more susceptible to developing kidney failure after ingesting acorns,” said Stan Smith, program assistant for agriculture and natural resources in Fairfield County, Ohio. “Producers with oak trees in their pastures may want to consider moving their herd away from the dropped acorns or consider fencing off larger areas that are covered with acorns. Feeder calves will eat acorns out of curiosity and hunger. Older cows with more mature digestive systems seem to be less susceptible.”

Livestock producers who have oak trees in their pastures need to be on the lookout. Acorns can be a problem in the fall for livestock and green acorns can be more toxic than mature acorns. Cattle and sheep appear to be more susceptible to toxicity than goats. Horses won’t typically seek out the nuts due to their bitter taste, but the lack of quality forage may send horses searching for alternative food sources, and they pick up a few accidentally while foraging.

The buckeye family, which includes horse chestnut, yellow buckeye and Ohio buckeye, is another group of trees you won’t want to plant or have near your livestock as they are a threat to horses and cattle. Buckeye trees have leaves, nuts and twigs that are poisonous to farm animals. Every part of the tree is toxic if ingested. Glycoside aesculin and saponin aescin are found in the bark, leaves and nuts. Signs of sickness include anorexia, constipation and hard manure. Later stages of poisoning include dehydration and hematuria. Young buckeye plants are more toxic than mature trees. Keeping your animals from grazing in woodland areas can prevent buckeye poisoning.

Extreme caution should be used when dealing with walnut trees. Walnuts, which include the butternut tree (a.k.a. the white walnut), release a substance called juglone from their roots, which is toxic to many other trees and plants. Juglone is also found in the leaves, branches and nut hulls, and horses standing in wood shavings made from walnut trees can develop laminitis, a serious and sometimes fatal hoof disease. There is also evidence that simply being around walnut trees may be enough to trigger laminitis in some horses.

Cherries, especially wild cherries, are toxic to cows, horses, sheep, donkeys, mules, goats and any other mammal that grazes. Animals poisoned by cherry leaves often die very quickly after eating small amounts. Cherries and cherry trees naturally produce high levels of cyanide which is toxic to cows. Apricots are also unsafe for livestock, as they are associated with cyanide poisoning. Cyanide deprives animals of oxygen and can often lead to death.

Cattle will eat almost any plant, but they are especially fond of the apple-like fruit of the hedge apple tree. They will eat the fruit and foliage of this tree. Cattle will also eat other plants such as clover that are in the same general area. The downside to hedge apples is that cattle can choke on them.

While other maple trees are safe, the red maple leaves are toxic. Leaves wilting on the ground release a toxic chemical when ingested for up to a month after falling. Red maple trees are especially toxic to horses. Box elder trees are also highly toxic when eaten. Ingestion of the box elder can lead to muscle issues, weakness and muscle tremors. Cedar trees are also bad for all sorts of animals.

On the other side, some nuts and even fruits and vegetables are OK for livestock. Those include watermelon, celery, apples, bananas, carrots, strawberries, pumpkins, raspberries, grapes, pears and ripe tomatoes.

“This is not a complete list of trees that are toxic to livestock,” said Barry Whitworth, DVM and Oklahoma State University animal quality and health specialist for Eastern Oklahoma. “Other notables include black locust and box elder, but fortunately, the majority of trees are safe to plant around livestock, and as long as farmers and others do a bit of research before planting, they should be good to go.”