Nebraska Extension in Boone & Nance Counties

FIELD TEST KITS AVAILABLE 

"Annual forages like sorghum, sorghum x -sudangrass, and sudangrass can accumulate nitrates, which should be evaluated before grazing. However, another potential risk is prussic acid poisoning (cyanide), which can be lethal if ingested.

Forage sorghum (also known as cane) and grain sorghum (commonly referred to as milo) pose the greatest risk, with sorghum x -sudangrass having a reduced risk, but still a concern. Sudangrass has the lowest risk of the sorghums, but it is not a negligible risk. Prussic acid poisoning can occur in certain scenarios, such as new growth or following a frost. If these plants are fertilized with high rates of nitrogen fertilizers, the risk of prussic acid increases further. Shoots shorter than 15 to 18 inches are especially dangerous, particularly for the sorghums.

To minimize risk, wait until sorghum and sorghum x sudangrass plants are at least 24 inches tall and sudangrass is at least 18 inches tall before grazing. If you have regrowth in late summer that does not meet these plant height thresholds, you can either wait seven days after a killing frost before grazing or test the plants to assess prussic acid levels.

Frost poses a significant risk because prussic acid forms in plants when cell membranes are damaged by freezing. This allows chemicals within the plant cells to combine and produce cyanide. After seven days, any cyanide generally dissipates into the air. However, each freeze that does not completely terminate plant growth results in an additional seven-day countdown. A killing frost is typically considered to be around 24°F. However, dense stands may require a longer, sustained cold period to achieve a full termination of growth.

To mitigate this risk, one strategy is to pull cattle off pastures when frost is forecast and then wait seven days after a killing frost before grazing. However, the period between the first frost and a killing frost can sometimes be prolonged, with frost-free intervals where grazing might seem feasible. During these windows, testing the forage for cyanide can provide valuable information, helping producers determine if it is possible to safely graze before the final killing frost occurs.

Using a Quick Field Test to Assess Prussic Acid Risk

Producers looking to assess risk in situations where plant growth is borderline or to confirm safety after a killing frost can perform a simple in-field test for prussic acid. This test screens for the presence of cyanide but does not provide exact concentrations. It can, however, give an indication of potential risk." *

Field test kits are available to screen for Nitrates and Prussic Acid in forage such as Johnson grass/Sorghum/Sudan grass. Instructions and test strips are included in the kit. If the results are positive, samples should be submitted to a lab for analysis and feeding advice. 

Stop in at the Extension Office to pick up a kit. 

*From "Avoiding Prussic Acid Poisoning in Grazing: When and How to Use a Quick Test" By: Mary Drewnoski, Nebraska Extension Beef Systems Specialist, Daren Redfearn, Retired Nebraska Extension Forage and Crop Residue Specialist, 2024

CATCH-A-CALF PROGRAM 

Applications for the 2027-2028 season are OPEN!

Participants come from Colorado, Kansas, Nebraska, and Wyoming to compete in the National Western Stock Show’s longest-running program of practical beef cattle management. In just over 80 years the Catch-A-Calf Contest has awarded nearly 3,000 steers to 4-H members hailing from the western United States.

The program began in 1935 when 10 boys caught 10 sponsored calves. The contest quickly caught on, and the program grew to include 52 calves by 1942. Soon after World War II, the program settled at 40 calves per year, which is where the number continues to stand today.

The program is designed so that successful participants catch a calf, feed it, and return with the animal one year later as a market-ready steer at the National Western Stock Show in Denver. The steers are judged on production and carcass quality, while the participants are judged on showmanship, record books, and a personal interview. The Grand and Reserve Grand Champion participants sell their steers at the Auction of Junior Livestock Champions held on the final Friday of the Stock Show.

This program is open to active 4-H and FFA members ages 14-18 (who must be residents) in Colorado, Kansas, Nebraska & Wyoming. For rules and regulations,and to apply, see the National Western Stock Show website. Applications are due January 1, 2027. Check out the schedule of events for the 2027 Catch-A-Calf show.