Sorghum Forage: A Resilient Option with Smart Management

By Shelby Gruss

Iowa State University Extension and Outreach has published a new resource for livestock producers, “Management Strategies of Prussic Acid Toxicity in Sorghum.” Sorghum is a fast-growing and reliable forage crop for livestock.

“As weather extremes challenge consistent forage production, sorghum offers livestock producers a reliable, high-yielding alternative — especially during drought or delayed planting,” said Shelby Gruss, assistant professor and extension forage specialist at Iowa State University.

While sorghum presents several benefits, prussic acid toxicity (hydrogen cyanide) in sorghum is a serious concern, particularly after frost or when plants are young or over fertilizing, said Gruss. According to the publication, cattle death can occur within two hours of ingesting prussic acid poisoned sorghum.

Strategies for managing prussic acid through different feeding options include proper grazing, silage and baleage.

“Silage and baleage production offer the safest choice for sorghum forage with high dhurrin accumulation. Dhurrin content can be reduced by 50% or more through chopping and fermentation,” said Gruss.

Key takeaways from the publication include:

• Avoid grazing young plants under 18 inches and monitor regrowth.
• Remove livestock from fields for at least one week after frost.
• Avoid over-fertilization with nitrogen.
• Test forage when in doubt to ensure safe feeding.

Livestock producers are encouraged to download the full resource, available at no cost, through the Extension Store.

If you have further questions about prussic acid toxicity in sorghum, contact Shelby Gruss at sgruss@iastate.edu.