Extension Viewpoints: Poisonous plants and grazing livestock

By Ethan Proud
PREVIEW Columnist 

Having given presentations on poisonous plants three times, it seemed only appropriate to write an article, as well. Many livestock producers and owners understand that, for the most part, their animals understand what to eat and what to steer clear of. Which begs the question, why do animals die every year from plant poisoning?

Events such as fall and spring storms may cover desirable forage and leave toxic plants more readily accessible, such as ponderosa needles. Other plants’ toxicity decreases and palatability increases, leaving a window in which most poisonings occur. 

Mismanagement of pastures and overgrazing can also lead to an infestation of toxic weeds such as Russian knapweed. Animals know not to eat that plant, but when faced with starvation, they will select anything green to eat. Plant poisoning can occur throughout the year and even during the winter. Certain plants like houndstongue are unpalatable while green, but become more appealing when dried and retain their poisonous characteristics. For this reason, it is extremely important to know where your hay is coming from — if you can buy weed-free forage, it will have a higher quality than noncertified hay.

Some of the most poisonous plants in our area include: larkspur, hemlock, death camas, milkweeds, houndstongue and Russian knapweed. The last two species are ‘noxious,” which should not be confused with “toxic.” The term noxious denotes that the species is non-native and either have no benefits or their negative properties outweigh the good. Not all poisonous plants need to be treated with chemicals — and the ones that do should be done so with care. 

Some herbicides cause plants to accumulate sugars, making them more palatable and can lead to poisoning. By grazing carefully, livestock producers can limit the exposure of their animals to poisonous plants by moving them to new pastures when they are likely to consume toxic plants. In the case of larkspur, the toxicity diminishes (but does not entirely go away) by the seed pod stage, which is typically midsummer. By keeping cattle out of areas with larkspur until midsummer, poisoning can be avoided.

Every year, plant poisoning causes a loss of $340 million annually. This cost in incurred by death of livestock, veterinarian costs, loss of pasture, additional feed and care, and treatment of poisonous plants.

Archuleta County Weed and Pest is your local resource for managing noxious weed populations and controlling other pests.

Archuleta County Fair

Archuleta County Fair will host the 4-H livestock shows and general projects only this year and limit participation to 4-H youth and their immediate families. There is no public admittance. The Livestock Auction will be virtual. 

Please go to https://www.archuletacountyfair.com/ to learn how you can stream the shows and participate in the virtual auction.

Donate to the Archuleta County 4-H program

The Archuleta County 4-H program boasts a membership of more than 150 members annually. Often, these programs rely on fundraisers to help offset the costs of the program, such awards, supplies and, most importantly, leadership opportunities. Members can attend various leadership camps and conferences statewide and even nationally. 

To help our program continue to support our members, we appreciate any contribution you make. To pay online, visit https://client.pointandpay.net/web/ArchuletaCo4H/ and select Contributions and Donations.

This story was posted on August 5, 2020.