During a drought, forages need to be monitored for nutrition and safety.
Call it “Don the Disappointment.” Tropical Storm Don, which many hoped would bring widespread and welcome rain to much of the western part of Texas, proved to be a dud as it fizzled out shortly after making landfall last week. Throughout the Lone Star State, with the exception of small pockets where there has been rain, producers continue to struggle with dropping irrigation wells and stock-water tank levels, desiccated pastures and hay shortages.
Here’s a sprinkling of reports from AgriLife Extension specialists around the state:
• "Different week, same song," says Rick Auckerman, AgriLife Extension agent for Deaf Smith County, west of Amarillo. "Producers are trying to run water on as many crops as possible, but the cotton is needing more water now also. The corn crop is in dire need of water, and many producers are abandoning parts or whole fields of corn production in hopes to salvage what they can."
• "All range and pastures are in extremely bad condition," says Lyle Zoeller, AgriLife Extension agent for Coryell County, west of Waco. "All classes of livestock were being fed heavily. Many cows are going to local market, as well as most calves 300 lbs. and over. There is no hay available in the area; most is coming from out of state. Low-water sources are now forcing sales of cattle."
• "Producers continue to cull herds as grazing gets shorter," says Mark Currie, AgriLife Extension agent for Polk County, south of Lufkin. "Time is running out for producers to make enough hay for their herds for winter feeding – even if they survive the summer. Livestock water continues to be a problem for many producers as stock tanks and creeks get lower or dry up."
• "Tropical Storm Don did not bring any measurable rain," reports Mile Gibbs, AgriLife Extension agent for Val Verde County, southeast of Fort Stockton. "Sheep look very good considering the drought and lack of vegetation. Lamb crops are down. Northern portions of the county need some rain just to cover the burned ground from the April and May wildfires. The ground is still bald and scorched."
Monitor forages carefully
Livestock producers can quickly lose animals if they fail to carefully monitor forages as the drought continues, according to a toxicology expert from the Texas Veterinary Medical Diagnostic Laboratory.
Tam Garland, toxicology section head, says producers should watch for high levels of prussic acid and nitrate that can build up in drought-stressed forages. Testing is the best way to monitor for these conditions.
Johnsongrass can become especially lethal during a drought, she says.
“Typically, we tend to see high levels of prussic acid in johnsongrass when we get hot weather or dry signs,” she says, “or when dry johnsongrass is exposed to a little moisture and grows very quickly. Prussic acid may also be high when johnsongrass is exposed to frost.”
Producers should beware when they see a ribbon-like appearance to johnsongrass leaves, she says.
“That’s a huge indicator it’s under drought stress and may be hot with prussic acid.”
Any of the sorghum species – such as haygrazer, sorghum sudan and some milo – may also contain high levels of prussic acid, she says.
Nitrate levels in forages are also a concern. Sorghum hybrids, corn and grain sorghum may contain high levels, as may silverleaf nightshade and pigweed or careless weed.
Livestock producers can take several precautions, Garland says.
First, producers should test all forages for high levels of prussic acid and nitrate. Each plant sample should include 10-12 plants, which should be randomly selected from a field. Cut samples about 3-4 in. above the ground.
Garland also advises producers to probe any hay that has recently been baled, if it was not tested before baling. “Take three or four probes, put those individual samples into a glass canning jar, and submit them to the lab for testing,” she says.
"If a round bale shows high levels of prussic acid levels," Garland says, "let the bale cure for 30 days, re-probe it and re-test it. Or, roll out the bale and air it out for five days, then re-bale the hay."
Additionally, producers should isolate their livestock from suspected plants, Garland says, including any that may grow on the other side of a fence or along a right-of-way. Farmers and ranchers should also take caution when moving cattle from one pasture to another.
Concerned producers should tightly control their livestocks' grazing, Garland says, and should consider supplementing – or replacing grazing entirely – with dry hay.
"This is especially true when forage test values for prussic acid are dangerously high," Garland says. "Finally, producers should be prepared to quickly treat animals that have ingested forage with high levels of prussic acid or nitrate. Treatment generally must take place within minutes to save an animal."
For sample submission instructions, visit tvmdl.tamu.edu/services_offered/forms/index_forms.php. More information on the current Texas drought and wildfire alerts can be found on the AgriLife Extension Agricultural Drought Task Force website at agrilife.tamu.edu/drought/.