Cyanide Cattle Death Could Have Been Avoided – University of Copenhagen

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25 July 2012

Cyanide Cattle Death Could Have Been Avoided

On a Texas farm in June, 15 cattle fell victim to a hybrid grass species containing abnormally high amounts of cyanide. Feed crops becoming toxic due to e.g. drought is a substantial problem for many farmers worldwide. In the future these accidents can be avoided by using non-toxic variants, such as the sorghum line developed by a group of Danish and Australian scientists.  

When the accident was first reported by American news media, journalists pounced upon the story without forming a full understanding of the underlying scientific facts. A CBS reporter thus filed a headline stating "GM-grass linked to cattle deaths". This triggered a surge of activity among bloggers and journalists warning about cyanide-producing GMO. As it turns out, they had jumped the gun; in fact, poisoning accidents such as these could be avoided in the future by putting a mutated acyanogenic line of the cereal sorghum into use. This sorghum line was identified by researchers from the Department of Plant Biochemistry at University of Copenhagen (some of which are also participating in Center for Synthetic Biology) and from Monash University in Australia. 

It is important that journalists ensure that their angle on a scientific news story has a foundation in the underlying science. Mr. Joe Schwarcz, Director of McGill University's Office for Science and Society did his to clear up the misunderstandings in the media by publishing an article of his own: In fact, the grass was a species developed using traditional cross-breeding methods, and it was in no way a novel GM-product. It had been around since 1983. While many plant species produces defensive compounds able to release cyanide (cyanogens) the amounts found in the grass on this specific farm were abnormally high, even compared to other farms in the area. The reasons are unclear but untimely use of nitrogen fertilizer on the land might be a part of the explanation, as this can lead to cyanide release. 

The aforementioned cyanide-free sorghum line developed by Australian and Danish scientists was developed by substituting a single amino acid in the sequence of a cytochrome P450 enzyme catalyzing the first commited step in the synthesis of the cyanogenic compound dhurrin. This change would keep the feed crop from turning toxic during periods of drought or over-fertilization, and could therefore potentially be used to solve a major problem for farmers around the world, especially in the drought-vulnerable agricultures in developing countries. 

The article by Joe Schwarcz can be read here:

The cyanide-free sorghum is reported in this paper in Plant Biotechnology Journal: