Marion Barnes, Senior County Extension Agent – Clemson University – July 2024
Drought can occur at any time. Feeding and nutrition of the cattle herd is the primary concern during extended periods of dry weather. Above-average temperatures and little or no rainfall limit forage growth and reduce hay production. Drought alone rarely kills forage species, but overgrazing during extended dry periods can cause persistent problems. Establishing annual forages like pearl millet due to the drought can also be challenging. During times of drought, cattle producers often face several drought-related cattle feeding issues, including nitrate toxicity, salt toxicity, non-protein nitrogen (ammonia) toxicity, prussic acid (cyanide) poisoning, cattle consuming toxic plants, and other related issues.
The following are a few suggestions when dealing with drought-related grazing and feeding issues:
- Hay cut under moisture stress conditions may contain high nitrate levels. Have all hay purchased or grown on the farm tested for nitrites before feeding.
- Water intake during hot weather increases by 5 to 6 or more gallons per animal per day. The use of salt to limit feed supplement intake may increase water intake by 50 to 75 %. Salt toxicity can result when excessive quantities of salt are ingested and when the intake of clean, fresh water is limited. Check your water supply often to ensure cattle have access to clean water.
- Cattle grazing in short pastures is more likely to consume toxic plants. Many normally unpalatable plants may be consumed when grazing is in short supply. Scout pastures for plants that pose a poisoning threat and remove them before allowing cattle to graze.
- Prussic acid or cyanide poisoning can also be problematic when grazing drought-stunted forages like sorghum and sorghum-sudan grass hybrids. Take precautions to reduce prussic acid poisoning before grazing these forages. Prussic acid poisoning symptoms are similar to nitrate toxicity, but treatments are different, so make sure the problem is diagnosed correctly. Consult a veterinarian if you suspect livestock poisoning.
- Consider establishing annual summer forages like millets if emergency grazing is needed. Pearl millet grows well in hot conditions, but adequate rainfall is required for its establishment and growth. Nitrate toxicity can be an issue during times of drought with this forage.
Sources for this article include UGA Extension Publications Special Bulletin 51, Drought-Related Cattle Feeding Problems, Drought Management Strategies for Beef Cattle and Forage Use and Grazing Herd Management During a Drought.
Several publications dealing with drought management that you may find helpful include: Visit website:
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