Published: October 08, 2008 08:07 am            

FROST BRINGS DANGER

PRUSSIC ACID POISONING

As we move into October, the likelihood of frost increases. The best way to prevent losses from Prussic Acid is to be aware and plan ahead. The following information will help to be aware and prepared. The primary cause of hydrocyanic (prussic) acid poisoning in domestic animals is the ingestion of plants containing this potent toxin.

Cyanide-producing compounds (cyanogenic glucosides) occurring in living plant cells are converted to prussic acid when cells are crushed or otherwise ruptured.

The prussic acid potential of plants is affected by species and variety, weather, soil fertility and stage of plant growth. Plants of the sorghum group and leaves of wild cherry trees have a potential for producing toxic levels of prussic acid. There are wide differences among varieties. Some of the sudangrasses are low in prussic acid.

Pearl millet is apparently free of prussic acid in toxic amounts.

Cause: Prussic acid is one of the most potent toxins in nature. As ruminants consume plant materials containing cyanide-producing compounds, prussic acid is liberated in the rumen, absorbed into the bloodstream and carried to body tissues where it interferes with oxygen utilization. If toxin is absorbed rapidly enough, the animal soon dies from respiratory paralysis.

Symptoms: When lethal amounts are consumed, dead animals may be found without visible symptoms of poisoning. Symptoms from smaller amounts include labored breathing, irregular pulse, frothing at the mouth and staggering.

Prevention: Forage species and varieties may be selected for low prussic acid potential. The risk from potentially dangerous forages may be reduced by following certain management practices:

1. Graze sorghum or sorghum cross plants only when they are at least 15 inches tall.

2. Do not graze plants during and shortly after drought periods when growth is severely reduced.

3. Do not graze wilted plants or plants with young tillers.

4. Do not graze for two weeks after a non-killing frost.

5. Do not graze after a killing frost until plant materials is dry (the toxin is usually dissipated within 48 hours).

6. Do not graze at night when frost is likely.

7. Delay feeding silage six to eight weeks following ensiling.

8. Do not allow access to wild cherry leaves whether they are wilted or not. After storms, always check pastures for fallen limbs.

When in doubt, don’t graze.

For more forage information, visit our UK Forage Extension Web site at: http://www.uky.edu/Ag/Forage or call the Madison County Extension Service at 623-4072.

Weaning deadline for sale

Don’t forget that the deadline for weaning calves to be in the Richmond CPH-45 sale is Saturday. This sale is a PVP sale, which means calves need to be raised on your farm. Sale date is Tuesday, Nov. 25, at the Bluegrass Stockyards of Richmond. For more information, call the Madison County Extension Office at 623-4072.

Educational programs of the Cooperative Extension Service serve all people regardless of race, color, age, sex, religion, disability or national origin.

        

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