DALLAS — The sun was setting when Jerry Abel's cattle began to bellow on his Central Texas ranch. They were convulsing by the time he rushed to the pasture. Within hours, Abel had lost almost all his herd.
The culprit: toxic grass.
Abel's 15 dead cattle represent the first documented case of cyanide deaths being linked to a common Bermuda grass hybrid found in grazing lands across Texas. Although the incident in late May initially sparked concern from other ranchers who use the same grass, state agriculture experts say they believe the problem is isolated and there is no cause for alarm.
"If cattle are already on pasture, don't worry about it," said Larry Redmon, a specialist with Texas A&M AgriLife Extension Service, which worked with state and federal agencies to investigate the deaths. "Chances are it's not going to be an issue." But, he said, "I would never say never."
Preliminary results from the investigation show Abel's Tifton 85 grass contained cyanide, or prussic acid, though Redmon said what caused the poison to build up remains unclear and is under investigation.
The grass, a warm-weather perennial grown south of the Red River, was released to ranchers in 1992 for its drought resistance and nutritive value and is perhaps the most commonly used Bermuda grass variety in Texas, the nation's leading cattle state.
Since other grasses such as sorghums or Sudan can pose cyanide danger, most ranchers know to wait seven to 10 days after new growth before sending cattle to graze, Redmon said. That allows the grass time to release the cyanide into the atmosphere.
But because this is the first reported case of deadly levels of prussic acid in Bermuda grass, Abel, 69, had no idea his cattle were in danger. He has been a rancher since 1977 and growing Tifton 85 on his pasture northeast of Austin for 15 years.