Released July 11, 2008
By Robert Seay Benton County Extension
BENTONVILLE, Ark. - I prefer to call this a review of possible disorders rather than to create more confusion about forage toxins in regards to horses. To set the record straight, I know little, or nothing about horses. I made up my mind to maintain a distance from all equine subjects when, at the age of 5, I fell off my stick horse.
However, a few years ago, Steve Jones, extension horse specialist, kindly reminded me that any effort to promote marketing of high quality Bermuda hay must begin with horses. Having cleared that up, let’s consider prevention or avoidance as a cure for horse ailments related to other forages.
Most horse owners are probably aware of toxic landscape plants (Japanese yew, apple trees, red maple, etc.) and have removed them from the premises. What about toxic-prone grasses commonly grown in this area?
Whenever forage plants are suspected as the cause of an ailment, either the source, or the horses should be removed. This may seem drastic, but it’s critical since treating animals for plant toxicity is often a belated step. Situations also get complicated because of seasonal variations in plant toxins and, as with humans, individual animals often respond differently to toxins.
To err on the side of safety seems a practical course.
Plants in the sorghum family (Johnson grass, Sudan grass, etc.) occur on many farms. Johnson grass is a perennial that often grows uninvited, while Sudan grass and its hybrids are often grown as a forage crop for cattle.
They can accumulate toxic levels of hydrocyanic acid (prussic acid, cyanide) especially when stressed due to drought, frost, etc. Also, these plants can accumulate toxic levels of nitrates under certain conditions. While horses may not be as sensitive as cattle to certain forage toxins, the risk factor deserves your attention.
Tall fescue is the most popular perennial grass in northwest Arkansas. Its chemical components, which enable its persistence, also prove to be sources of toxins when used as pasture or hay. Although non-toxic fescue varieties are available, old strains must be completely eliminated prior to making a new planting. That has proved to be no easy task for the weak-hearted!
Millet forages also present a complicated case since a number of different grass species are sold under the trade name, Millet. Those in the sorghum family present the same health issues as Johnson or Sudan grass. Some species are safe, but information often lumps millet health risks under a single umbrella, which confuses the issue.
If you ask 20 old-timers about forages for horses, you could get 20 versions of which forages can, or can’t be used successfully. (Refer to paragraph four above.) Being independent-minded, you may develop a middle-of-the-road plan to fit your set of circumstances. At that point, turn right and proceed with caution! Til’ next week!
For more information about forages and horses, contact your county agent for more information or visit http://www.uaex.edu and select Agriculture. The Cooperative Extension Service is part of the U of A Division of Agriculture. --30--
http://www.uaex.edu/news/july2008/0711seay.htm
Contact: Lamar James, (501) 671-2187, ljames@uaex.edu
