By Jared Groce

Late summer has been brutal on our livestock, our grass and the rural land market in North Texas. We currently have an astounding 42 months of inventory on hand in our report area, and the only properties selling are the ones priced right. Overpriced properties aren’t even getting looked at, much less receiving offers, so pricing your property correctly matters more than ever right now.

Many sellers are still picturing the daily price increases we saw in 2020 to 2023, but those days are behind us, and agents need to be more realistic with listing prices to get any activity for their clients. Hopefully the rains will come soon and bring more land buyers with them this fall, but right now it is still very much a buyer’s market. No one knows how long this dry spell will last, but it will likely take a flood to end it. The same is true of the weather!

They say the best time to plant a tree, or buy land, was 20 years ago, and the second-best time is today.

DOM = days on market

By NTFR Staff

The first frost feels like a clean break between seasons, but for cattle producers it can open a short window when familiar forage deserves a second look. Frost can change plant chemistry, end active growth and upend grazing plans almost overnight. The bigger concern is what frost does to certain plants, particularly members of the sorghum family.

Johnsongrass, forage sorghum, sorghum-sudangrass hybrids and related plants can contain compounds that release hydrogen cyanide, commonly called prussic acid, when plant tissue is damaged. Drought stress can raise the risk, and frost can make it worse. Frost ruptures plant cells and brings the compounds that form prussic acid into contact, creating forage that can be dangerous even though it may still look green and palatable.

Prussic acid acts fast. The rumen releases it, and it is absorbed into the bloodstream, where it keeps cells from using oxygen properly. Signs may include rapid breathing, muscle tremors, salivation, staggering, convulsions and collapse. In severe cases, producers may find a dead animal before seeing any obvious symptoms.

That is why Oklahoma State University recommends keeping cattle off frost-damaged susceptible forage for at least seven days after a killing frost, and until the plants are completely dry and brown. A light frost can be trickier. If the plant survives, new shoots or tillers may emerge, and that young regrowth can be especially high in prussic acid. Don’t turn cattle back in just because a few warm afternoons followed the frost.

The practical question is always the same: Is this field risky? Species matters. Johnsongrass and sorghum-type forages deserve attention. Pearl millet and foxtail millet, by comparison, have much lower prussic acid potential. If you aren’t sure what is growing in a field, identify it before you make a grazing decision.

Prussic acid vs. nitrates

Nitrate toxicity is a separate issue. Producers sometimes lump nitrates and prussic acid together because both are associated with stressed forage, but they behave differently. Prussic acid can dissipate as forage dries. Nitrates don’t simply disappear after frost, wilting or baling. Nitrate can remain in hay and other stored forage. When drought, heavy nitrogen fertilization, cloudy weather or other stresses have raised concerns, a lab test is the safest way to know what your cattle are getting.

Frost also changes how you should think about haying or baling suspect forage. Prussic acid is volatile and can dissipate during proper curing, so well-cured hay from a sorghum-type crop is generally a different risk than freshly frost-damaged grazing. Nitrates are the opposite problem. They stay in the forage after baling, so a nitrate test can matter more than appearance. Ensiling can lower nitrate concentration somewhat, but it doesn’t guarantee safety. Testing is still the better choice.

The toxins also sit in different parts of the plant. Prussic acid potential is often greatest in young leaves and new growth, while nitrate tends to build up in the lower stem. That matters when you are deciding whether to graze, cut high, bale or sample a field. A lab result is only useful if the sample represents the forage your cattle will eat.

Don’t use color as a safety test, either. A plant can look dry while nitrate remains, and a green plant isn’t automatically high in prussic acid. Species, recent stress and lab testing carry more weight than appearance. When the forage is valuable enough to graze or feed, a test is cheap compared with losing cattle.

A management checkpoint

The first frost also changes ordinary pasture management. Warm-season grasses stop putting on meaningful new growth, and what is standing becomes a finite supply. Cattle that have spent months picking the best leaves may start taking lower-quality stems and plants they used to ignore.

A killing frost can also open up plants cattle previously passed by. Leaves drop, stems turn brittle, and cattle may reach low spots along fence rows or ditches. If johnsongrass has been growing unnoticed at the edge of a pasture, frost is a good reason to notice it now. The same goes for volunteer sorghum in crop residue or waterways.

For cow-calf producers, the first frost makes a convenient checkpoint. Fall-calving cows may be entering peak nutritional demand. Spring-calving cows may be in mid-gestation and easier to keep up, but thin cows still need time to gain condition before winter. Reassess body condition, available forage and whether you need to start supplementing. Waiting until cows lose condition makes the fix more expensive.

Check water, too. Cooler weather may reduce how much you see cattle drink, but they still need ready access to clean water. A sudden cold snap can expose leaking floats, weak heaters or water systems nobody has checked since last winter.

North Texas weather rarely changes in a straight line in the fall. A frost may be followed by warm afternoons, then another cold front, so the plants tell you more than the calendar does. When susceptible forage is involved, give frost-damaged plants time to cure, and remember that new growth can restart the clock.

The simplest first-frost plan is to walk the pasture before moving cattle. Identify sorghum-type plants and johnsongrass. Look for patches that were already drought-stressed. Check whether a light frost has triggered new growth. If you have any doubt, keep cattle out and have suspect forage tested through a qualified lab or Extension office.

The most dangerous part of first-frost management is assuming cold weather solved a forage problem. Prussic acid responds to time and curing. Nitrates don’t go away on their own, and ordinary pasture quality keeps declining even when plenty of standing material remains. Frost marks the start of a new management season. A few minutes spent identifying plants and thinking through the previous week’s weather before you open a gate can prevent a problem that develops in minutes once hungry cattle start grazing.

By Barry Whitworth, DVM

Scrapie is a chronic, progressive disease of the central nervous system that affects sheep and goats. The U.S. Department of Agriculture (USDA) has worked for decades to eliminate scrapie from small ruminant operations. The United States was positioned to meet the World Organization for Animal Health’s seven-year benchmark for self-declared scrapie freedom in January 2028. Unfortunately, the Animal and Plant Health Inspection Service (APHIS) confirmed classical scrapie in a sheep slaughtered at a facility in Oregon. With this detection, national scrapie-free status for the U.S. may be pushed back to sometime in 2033.

Scrapie is the oldest of the neurodegenerative diseases known as transmissible spongiform encephalopathies (TSEs). Other TSEs include bovine spongiform encephalopathy, known as mad cow disease; chronic wasting disease, found in deer; and Creutzfeldt-Jakob disease, found in humans. TSEs are protein-misfolding diseases that damage the brain, and they are always fatal.

Researchers don’t fully understand what causes scrapie, but evidence points to an infectious protein called a prion. These infectious prions damage the normal prion proteins found in the brain. The misfolded proteins lead to brain damage and the clinical signs of the disease. Prions resist destruction, so once they are in the environment, they are difficult to remove.

Scrapie appears to spread mainly by the oral route. Lambs and kids typically ingest prions when they contact placentas and birthing fluids from infected ewes and does. Older animals can be exposed the same way. Colostrum and milk are also sources of prions, and urine, feces, saliva and nasal secretions may contain them as well. Once ingested, prions cross into the lymphoid system, where they incubate for a long time, usually two to five years, before entering the nervous system.

Genetics plays a part in scrapie infections. Some breeds are more susceptible because of their genetic makeup. Genetic testing can help producers select breeding stock with resistant genes.

The clinical signs most associated with scrapie are intense itching (pruritus), incoordination (ataxia) and wasting. Early on, producers may notice slight behavior changes in infected sheep and goats. Animals may have a staring or fixed gaze, fail to respond to herding or act aggressively toward objects. As the disease progresses, signs include weight loss despite a normal appetite, incoordination, head tremors and intense itching. In the final stages, sheep go down and may show blindness, seizures and an inability to swallow. Once the first clinical signs appear, death usually follows in one to six months.

The gold standard for diagnosing scrapie after death is immunohistochemistry testing of brain tissue, along with microscopic examination of the brain for the lesions characteristic of TSEs. Veterinarians can also diagnose live animals by testing lymphoid tissue from the third eyelid and rectal mucosa scrapings.

No treatment exists for scrapie, so prevention is key. Biosecurity is a good starting point. Maintain a closed flock, and buy replacement animals only from certified scrapie-free flocks. Limit visitors’ contact with your animals. Keep lambing and kidding areas clean, and dispose of manure and bedding contaminated with birthing fluids and placentas properly. Use genetically resistant animals for breeding to produce genetically resistant offspring.

A novel, or atypical, form of scrapie also exists. Sometimes called the Nor98 variant, it was first found in Norway and has been diagnosed in the U.S. as well. It usually turns up in a single old animal in a flock or herd, and its brain lesions differ from those of classical scrapie. Experts currently believe natural transmission of atypical scrapie is unlikely.

Small ruminant producers can help the USDA’s eradication effort by contacting the agency when an adult sheep or goat shows clinical signs of scrapie or when an adult animal dies or is euthanized. Contact Oklahoma State Veterinarian Dr. Rod Hall at 405-522-6141 or USDA Veterinary Services at 405-254-1797. Collection and testing of samples for scrapie are free.

Another important step in eliminating scrapie, and other diseases, is identifying animals with official USDA ID. The USDA National Scrapie Eradication Program requires most sheep to be identified to their flock of birth when they leave their home premises for sale, show or events, or when they commingle with other sheep.

Unfortunately, the Oregon sheep diagnosed with scrapie had no tag, which will hamper USDA traceback efforts. You can find more information on official ID at https://www.aphis.usda.gov/nvap/reference-guide/animal-identification/sheep-goat.

The U.S. needs to eliminate scrapie. Once it does, the country will gain additional export markets for sheep and goat products. Oklahoma State University Cooperative Extension Service has an informative fact sheet on scrapie. Ask your local county Extension office for fact sheet VTMD-9135, or view it online at https://extension.okstate.edu/fact-sheets/scrapie.html. Sheep and goat producers may also want to visit the USDA National Scrapie Eradication Program website at https://www.aphis.usda.gov/livestock-poultry-disease/sheep-goat/scrapie.

References

Cassmann, E. D., & Greenlee, J. J. (2020). Pathogenesis, detection, and control of scrapie in sheep. American Journal of Veterinary Research, 81(7), 600–614. https://doi.org/10.2460/ajvr.81.7.600