On-Farm Research
Have you ever wondered whether a new product or management practice actually pays on your pasture, hayfield or forage acres? Consider putting that question to the test through the Nebraska On-Farm Research Network.
The Network partners producers with Nebraska Extension to answer questions under real farm conditions, using your equipment and management practices.
Maybe you want to compare fertilizer or weed-control programs, forage varieties, seeding rates, irrigation strategies or grazing practices. The research question starts with you. Extension can help design the trial, collect data and analyze results to determine how a practice affects forage production, quality or economic return.
And remember, learning that a new practice doesn't pay can be just as valuable as finding one that does.
Have a pasture or forage question worth testing? Contact your local Nebraska Extension educator or the Nebraska On-Farm Research Network.
Frosted Sorghum and Prussic Acid
As fall progresses, temperatures continue to drop and chances of a freeze grow. Do you know how frost affects forage safety and what precautions can protect livestock?
Short-term freezing temperatures may cause sorghum species, including sorghum-sudangrass, grain sorghum (milo) and forage sorghum, to become lethal to livestock. Freezing damages plant cells, allowing compounds such as dhurrin to break down and release hydrogen cyanide (HCN), also known as prussic acid. This cyanide compound can be deadly to livestock if consumed. Sudangrasses have the lowest risk, while forage and grain sorghum have the highest. Millet species do not pose a prussic acid risk.
Every time another freeze occurs without temperatures low enough to completely kill the plants, that seven-day clock resets, just like the 30-minute lightning delay at football games. The new growth on sorghums that have had frost damage is very dangerous as it can have the highest concentrations of prussic acid.
If there is a chance of freezing temperatures, remove livestock from the pasture and wait seven days before grazing once again. The hours immediately after a frost have the highest level of toxic compounds. If there is regrowth in the days after a freeze, wait to begin grazing until those shoots are 15–18 inches tall or seven days after the plant has been completely killed by the frost.
Recent research also suggests that drying sorghum for hay is not a guaranteed fix. While some HCN can dissipate during drying, dhurrin may remain in dried sorghum hay and still release HCN during digestion. Hay made from drought-stressed, immature or frost-damaged sorghum should be tested before feeding.
If sorghum family plants have had extra nitrogen applied, are growing in high nitrogen soils, or have been under drought stress, nitrates may also be a concern. Nitrates are a separate issue from prussic acid, so testing for both may be needed.
