Dhurrin-Free Forage Offers Safer Sorghum Grazing

Livestock operators in drought-prone regions can now evaluate a sorghum-sudangrass option without the prussic acid poisoning risk.

Updated on Nov. 3, 2026 in Agriculture

Dhurrin-Free Forage Offers Safer Sorghum Grazing

Live Poll

Would you plant dhurrin-free sorghum-sudangrass on your operation if available?

S&W Seed Co., based in Longmont, Colo., is releasing limited amounts of dhurrin-free sorghum-sudangrass, a forage crop developed at Purdue University and licensed exclusively to the company. The trait removes a compound that can release prussic acid, a toxin that can kill grazing cattle.

Why it matters

Sorghum-sudangrass grazing carries a poisoning risk during drought or fall grazing on stubble, and dry conditions in the Southwest and West make the crop widely used there. A forage option that removes this risk could change how livestock producers plan grazing and feed programs.

The dhurrin-free trait was developed over more than 10 years of screening and in-field testing, starting from plant mutations first identified in the early 2010s. A 10% yield reduction is cited only as a hypothetical tradeoff livestock producers might accept, and the stub provides no measured field yield data or commercial volume figures.

The players

S&W Seed Co.

A Longmont, Colorado-based seed company that holds the exclusive license to include the dhurrin-free trait in its forage product line.

Purdue University

A public research university whose plant-breeding program developed the dhurrin-free sorghum trait.

The details

Dhurrin is a compound that, when combined with plant enzymes and plant damage, can produce hydrogen cyanide, also called prussic acid. The compound also naturally protects young sorghum plants by deterring chewing insects, so removing it shifts the crop's pest profile. Dhurrin-free sorghum-sudangrass seed is planted without additional management steps, though growers are still advised not to graze regrowing plants after a hard freeze until several days have passed.

Early 2010s: first dhurrin-free plant mutations identified.
2023: limited release of dhurrin-free sorghum-sudangrass.
2024: wider release of dhurrin-free sorghum-sudangrass expected.

Market Landscape

The dhurrin-free trait is an exclusive licensing arrangement between a university breeding program and a commercial seed company, placing it in the growing pipeline of university-developed crop traits brought to market through licensing. The crop's relevance is tied most closely to dry-weather forage systems in the Southwest and West, where sorghum-sudangrass grazing is widely adopted.

Livestock operators in drought-prone regions should evaluate whether a dhurrin-free forage option fits their grazing plans and pest-management approach, since the crop removes the cyanide-release risk but changes insect protection. Seed buyers should watch the wider 2024 release, as the 10% yield tradeoff cited in the stub is hypothetical and not yet confirmed by commercial field data.

The takeaway

Operators planning sorghum-sudangrass grazing should track the 2024 wider release and compare yield and pest-management terms before changing seed programs. Growers should consult their seed suppliers and extension agents on grazing timing, as dhurrin-free grain sorghums remain several years away.