Long periods of hot weather and drought lead to poor forage growth and the development of toxic weeds in pastures.
This unfortunate natural occurrence may force livestock to graze on weeds they typically would not, and if toxic weeds are ingested, this can result in the death of cattle.
If you do not want to roll the dice and risk losing some cows, it is important to scout pastures and remove these weeds regularly before mortality occurs.
The safest methods to manage weeds and maintain a productive forage is to routinely test your soil, do not overgraze, maintain proper pH and nutrient levels and keep your pastures mowed.
When scouting pastures for toxic weeds, it is important to keep in mind that these plants typically grow around trees, in ditches, near the edges of pastures and along fencerows and tree lines.
Toxic weeds typically appear in the summer, fall or any dry period following a drought.
Weeds in forages can be tricky to manage considering that some weeds actually have high nutritive benefits and may not be bad for livestock until they reach the mature stage.
While ingesting some varieties of weeds can be fatal to cattle, others can cause poor flavors and odors in meat and milk.
There are around 20 toxic weeds in the Southeast, and although it is possible for more to appear in North Georgia, there are a few common ones you should know about.
Johnsongrass, Perilla mint, Pigweed, Poison hemlock, Horsenettle, Buttercup and Black locust are commonly reported to cause serious symptoms with cattle, horses and small ruminants.
Although younger animals are usually the most vulnerable to fatal interactions with these weeds, mature livestock can show symptoms such as anorexia, vomiting, diarrhea, weakness and paralysis.
A few factors that can contribute to livestock consuming toxic weeds is if they have recently been moved to a new paddock, the animal is in poor condition or there has been a recent herbicide application.
If you are scouting a pasture and notice toxic weeds are present and may have been consumed by livestock, call your local veterinarian or Extension agent immediately to determine what steps need to be taken.
In the event of finding a dead cow in the pasture with no obvious cause of death, be sure to call your local Extension agent, examine the stomach contents for toxic plant ingestion and remove livestock from the paddock until all toxic weeds have been removed.
