This time of year we always receive calls regarding the safety of johnsongrass for cattle and horses. Actually, it’s not just johnsongrass producers who need to be concerned with.
Many sorghum- and sudan-type plants, including johnsongrass, can release a poisonous substance known as prussic or hydrocyanic acid. Even though we’ve had decent amounts of rainfall this year, I have still heard reports of some cattle deaths in the area due to prussic acid. Fortunately neither local veterinarian I talked to last week had treated any cases.
There are some losses of cattle almost every year due to grazing on the green plants. Silage and hay can usually be fed without problems.
The prussic-acid content decreases as the plant approaches maturity. Small plants, young leaves and tillers are usually the highest in prussic acid. In other words, upper leaves will contain more acid than older lower leaves.
Drought-stricken and second-growth plants are dangerous because they are small and consist largely of leaves, which are high in prussic acid. Poisoning seems to be less likely if animals eat some grain before they are turned into the pasture.
The remedy is an intravenous injection of sodium nitrite and sodium thiosulfate. However, if cattle are grazing contaminated pastures, death can come quickly. Therefore, if you have pastures with johnsongrass present, it is advisable to have a sample sent to the TAMU diagnostic lab before taking an unnecessary risk.
The 2010 Ranchers Gathering has been set for Tuesday, Aug. 24, at the Decatur Civic Center. Doors will open around 5 p.m. for everyone to visit booths. Dinner is set for 6. The $10 registration fee covers the meal and makes you eligible for one of the many door prizes.
Judon Fambrough, senior lecturer at the Texas Real Estate Center at Texas A&M University, will discuss “Hints on Negotiating Easements in Lieu of Condemnation,” a hot topic for many Wise County landowners.
Registration deadline is Friday, Aug. 20, at the Wise County Extension office at 206 S. State Street in Decatur. Checks can be made to: Extension Livestock Committee.