“Mom, are you calling me on Snapchat on purpose?”

Kern rebecca
Animal Scientist / Ward Laboratories Inc.

“I love you … ” says a very frightened, out-of-breath voice several times before the phone cuts out.

Pure panic went through my body, thinking maybe my mom was in a car accident. She seemed to think this was the last conversation she might have with me. Of course, with spotty cell service, nothing but panic and confusion came across.

A few moments later, my dad called and explained that my mom was in an ambulance being transported to the hospital after having eaten a nut I had never heard of in my life: an apricot nut. She had seen them online, advertised as an antioxidant-rich food with anti-carcinogenic properties. Wanting to be as healthy as possible, she ordered a bag from Amazon to try. The bag said in tiny, almost illegible letters, “Consume no more than three nuts per day” and “Keep out of reach of children.” Yet, it was still just in a resealable, zip-close bag. Thankfully, my mom had read those tiny letters and only ate three of the tiny, almondlike nuts.

Rapidly, she began experiencing symptoms, including difficulty breathing and a racing heart. She called on her way to the hospital because she thought it was a nut allergy. She believed her throat was closing and that she was on her way to having a heart attack! The medics in the ambulance and doctors in the ER seemed to think this was the case as well. They gave her some Benadryl, IV fluids and sent her home when she was breathing better.


However, something else wasn’t quite right. She was also having seizures. My dad started reading the reviews of the product on Amazon and let the doctor know people were expressing that this uncommon nut was known for being toxic. He was, unfortunately, ignored by the doctor and my mom did not receive the correct treatment.

When my dad was relaying this information about the apricot nut being toxic, it clicked! This was prussic acid poisoning. I have consulted many producers about prussic acid’s potentially deadly effects in beef cattle who graze specific species of forages (sorghums, sudangrass and johnsongrass, to name a few). However, through consultations and reading various articles, I remembered an unusual fact.

Once, a customer wanted to test their chokecherry jam for prussic acid because cyanogenic glycosides, which can be converted into cyanide through chewing, are present in cherry pits. In conversing with that individual, they also mentioned cyanogenic glycosides being present in peach pits. I realized that apricots and peaches are similar and, sure enough, apricot nuts can also cause prussic acid poisoning. We did not test the chokecherry jam, as we are not a food-grade lab, but the unique request stuck with me.

Typically, when producers ask me about the signs and symptoms of prussic acid poisoning, I state, “Dead cows.” The toxicity occurs so quickly that they are often found dead. However, when a small dose is consumed slowly, symptoms can include exactly what my mom experienced: difficulty breathing, elevated heart rate, muscle tremors and convulsions (seizures). Thankfully, my mom read the bag, and my dad didn’t open the Amazon box and help himself to a handful of the apricot nuts!

So, this grazing season, don’t end up with dead or seizing cows in your pasture. Do all you can to prevent prussic acid poisoning in your herd. Here are six preventative measures you can take to avoid your cattle experiencing what my mom just went through.

  1. Choose varieties of forage that don’t accumulate as much of the toxic compound. Sorghums typically accumulate more cyanogenic glycosides than sudangrasses. Usually, hybrids fall somewhere in between. However, plant breeders have made progress in offering hybrid varieties that accumulate less prussic acid. Work with a forage agronomist to determine what variety will work best for your operation based on your goals.
  2. Plant forage mixes. We often choose to plant sorghums and sudangrasses because of their ability to produce a lot of biomass. Consider planting these as part of a mix, including other species that are not known for prussic acid accumulation. This will potentially have a dilution effect on the concentration of prussic acid in the overall diet. These other species could include legumes, such as vining cowpeas, which would have the benefit of adding higher protein to the forage mix as well.
  3. Time grazing to coincide with the late-boot stage. This also creates a dilution effect. With more available forage, the toxic compound is less concentrated than during the early stages of growth.
  4. Use an intensive grazing management technique. Use electric fencing to mob graze forages to avoid selective grazing. If animals are allowed to selectively graze, they will choose to eat mostly leaves, which is where the acid accumulates. If they are forced to consume stems and stalks as well, then the concentration of prussic acid in the overall diet will be less.
  5. Fertilize according to soil test reports. Applying high levels of nitrogen can result in nitrate issues. Additionally, high nitrogen application on soils deficient in phosphorous and potassium has the potential to stress the plant and increase prussic acid accumulation.
  6. Test, test, test. Prior to turning cattle out to graze, go through the field and pull 20 leaves from different plants in various areas of the pasture. Submit these leaves to a forage testing lab to determine if the concentration of prussic acid is low enough to safely turn cattle out to graze. If it is high, you have three options.
    1. Wait for the plant to mature and test again, waiting until prussic acid levels have decreased.
    2. Wait for a hard-killing frost and graze seven days after.
    3. Hay it! The gas dissipates through the conditioning and drying process, so prussic acid is not a concern in baled hay.

I cannot express how relieved I was to learn my mom was doing well the day after receiving that very shocking phone call. However, never in my wildest dreams would I have guessed my own mother would experience prussic acid poisoning! There are several lessons here. First, don’t believe everything you read on the internet. Second, always read labels, it might save your life! Third, if you can’t find it in your supermarket, there is probably a reason. Finally, such a dramatic brush with prussic acid poisoning motivated me to give producers some management advice to ensure a successful, nontoxic grazing season.