As if running out of feed wasn't challenging enough, drought grows plant toxicity and its potential for poisoning livestock.
"Stressed pastures bring out toxic plant problems in several ways," says Dave Sparks, DVM, Oklahoma State University Extension food animal quality and health specialist. "At these times, toxic plants become more prevalent. Many toxic plants are able to withstand the stress of overgrazing better than more palatable forage plants. As the stress on the pasture continues, decreased competition means greater populations of toxic plants. Many of the toxic plants become more toxic under stress conditions such as drought or overgrazing."
In the same May 12 "OSU Cow-Calf Corner" article, (cowcalfcorner.okstate.edu/upcoming.htm), Sparks explains short forage can also cause protein, energy, mineral or vitamin deficiencies. These, in turn, make cattle more vulnerable to plant toxicity.
Though there's no preventing drought, stocker producers can take steps to manage the risk of potential livestock poisoning that comes with increased plant toxicity.
Specifically, Charles Hart, Texas A&M University Extension (range specialist) and Bruce Carpenter (livestock specialist), say producers should learn how to identify toxic plants, use effective grazing and livestock management practices and take measures to control the plants when necessary.
As for identifying toxic plants, livestock symptoms and all of the rest, check out the Toxic Plant Database at: (texnat.tamu.edu/CMPLANTS/toxic/index.htm).
Once you've identified the toxic plants, Hart and Carpenter say these steps can help prevent poisoning: Practice good grazing management, which is probably the most effective way to deal with potential toxic plant problems.
Use effective livestock-management practices, such as closely observing animals new to an area, grazing with the proper class of livestock, and implementing proper supplemental feeding strategies.
Recognize when plant control is necessary and what type of control is best. Control strategies that target infestations before they become large problems are generally the most economical. Go to farwest.tamu.edu/rangemgt/pdfs/Drought5.pdf for more details in a fact sheet by Hart and Carpenter.