||This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. (August 2012)|
Tifton 85 is a hybrid strain of Bermudagrass. Bermudagrass Cynodon dactylon is a forage perennial grass that originated in Africa and was brought to the United States as a pasture and hay crop for the humid Southern states. This variety was incorrectly reported by CBS News to be a genetically modified organism (GMO). It is not genetically modified.
In June of 2012 15 head of cattle in Bastrop County, Texas (near Austin) died of Prussic acid poisoning related to the consumption of Tifton 85. Prior to this event the cattle had been fed this grass for 15 years with no toxicity issues.
Hydrogen cyanide (Prussic acid) is a poisonous chemical compound with chemical formula HCN, is a cyanide-containing compound. It is produced by certain plants under conditions of plant stress such as drought or frost. Cattle ingest the plant, and during digestion the cyanide compound is released. Risks are highest when grazing frosted sorghums and Sudangrasses that are still green.
Hay from these grasses stored for two months or more losses all its cyanide content.
Other plants that can produce Prussic acid under certain conditions are the Sorghum family, including both forage sorghum and grain sorghum (highest levels) , Sudangrass, Johnsongrass and Bermudagrass. Included as well are The Prunus family; wild black cherry, choke cherry, and pin cherry. Green flax can also produce this compound. Some non-hybridized strains can produce cyanide compounds .
Factors which increase cyanide concentration:
- Young, rapidly growing plants
- Mature plants that are stressed due to such conditions as drought, frost, wilting and trampling, herbicide damage, heavy nitrogen fertilization, and disease conditions.
Under normal growing conditions susceptible plants do not contain dangerous levels of cynaide compounds. Nitrate toxicity is another similar problem which can occur under certain conditions and can affect any plant.
- Minimizing the Prussic Acid Poisoning Hazard in Forages AY-196 C. L. Rhykerd and K. D. Johnson Agronomy Department, Purdue University Purdue University http://www.agry.purdue.edu/ext/forages/publications/ay196.htm
- The Merck Veterinary Manual.2006; Merck & Co., Inc. Whitehouse Station NJ, USA. Available on-line at http://www.merckvetmanual.com/mvm/index.jsp
- Nitrate and Prussic Acid Toxicity in Forage. MF 1018. Cooperative Extension Service, Kansas State University, Manhattan. Available on-line at http://www.oznet.ksu.edu/library/crpsl2/MF1018.PDF
- Precautions When Utilizing Sorghum / Sudan Crops as Cattle Feed . 2006. University of Missouri Extension. Available on-line at http://agebb.missouri.edu/drought/sudan.htm