Extension Report

Baldwin County Extension Office

302A Byrne Street

Bay Minette, AL  36507

Telephone (251) 937-7176 or

928-0860/943-5061 ext. 2222

FAX (251) 937-7285

Anthony Wiggins

Regional Extension Agent/Animal Science & Forages

October 25, 2011

Be Aware of Potential Toxicities to Cattle This Fall

Every year I get at least one call or hear of someone who has lost some cattle due to some kind of toxicity.  It may have been from eating poisonous plants, high levels of nitrates in forages, prussic acid accumulation in plants, or something similar.  Typically, each instance could have been prevented if the producer had been aware of the hazard.  Here are a few potential toxicity hazards that cattle producers should be aware of this fall.

Perrila Mint.  This is a plant that is highly toxic to cattle when eaten in significant quantities.  I have seen this plant often on farms that I have visited.  Typically it grows in more shaded areas of pastures which are where cattle often congregate.  Usually, cattle will not eat the stuff, or at least not enough to kill them, but when cattle are confined to an area where feed is limited then it can become a problem.  Often when confined to areas where perrila mint is present, cattle will eat this plant out of boredom, not hunger, and the result is death.

Nitrate Toxicity.  Anytime we experience drought conditions, nitrate toxicity should be a concern for cattle producers.  Generally, forages that were heavily fertilized with nitrogen are the ones to be concerned with; however, nitrates can accumulate even when recommended nitrogen fertilization was followed.  The problem occurs when the plants take up nitrogen but does not have enough moisture to convert it into plant tissue.

Forages more susceptible to containing toxic levels of nitrates include corn stalks, sorghums, sudan grasses, millets, and to some extent bermudagrass.  Forages that contained toxic levels of nitrates and were baled as hay will still contain toxic levels when they are fed.  If you are concerned about your forages having toxic levels of nitrates, have it tested to be sure of the nitrate levels.

Prussic Acid Poisoning.  Prussic acid poisoning is generally a concern for cattle producers following a frost.  After a frost, plants such as Johnson grass and others in the sorghum family produce prussic acid and eventually cyanide.  This is very toxic to cattle, but unlike nitrate toxicity, prussic acid will leave the plant in about 14 days even if it is baled for hay.  Waiting a couple of weeks after a frost before feeding susceptible plants to cattle will prevent any problems concerning prussic acid poisoning.

Acorn Poisoning.  Acorn poisoning could be a problem in situations where there is limited grazing and cattle have access to areas where acorns are available to eat.  Acorns contain tannic acid and other tannins and can cause damage to kidneys and the digestive system when eaten.  Damage caused by the acorns may not be noticeable unless large quantities are consumed.  Keeping cattle out of wooded areas that contain oak trees is the best preventative measure to take in this instance.

While all of the above toxicities are potential problems that cattle producers should be concerned with this fall and should take precautions to prevent, one thing to keep in mind is that basically all things are toxic, it’s the lethal dose that matters.

Email address: wiggia1@aces.edu

Phone number: 937-7176 or 943-5061, 928-0860, ext. 2222

Baldwin County Extension Programs are supported by the Baldwin County Commission.

The Alabama Cooperative Extension System (Alabama A&M and Auburn Universities) in cooperation with the U.S. Department of Agriculture is an equal opportunity educator and employer.