Drought Affects Water Quality

Poor-Quality Water Due to Drought Can Have Negative Effects on Livestock

Russ Quinn
By  Russ Quinn , DTN Staff Reporter
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The quality of water from natural features such as ponds can deteriorate during drought. Producers need to monitor the situation and even test their water. (DTN file photo)

OMAHA (DTN) -- Drought in the Corn Belt and High Plains has forced livestock producers to adjust their operations to the extreme weather. Many have had to switch up their grazing numbers, find alternate sources of feed, or wean calves earlier to become more efficient in the face of dry conditions.

Another item cow-calf producers should monitor is the quality of water sources during drought. Dry conditions can affect water quality and raise levels of possible salts, minerals, and bacteria; all put livestock at risk.


In a recent Beef Cattle Institute (BCI) Cattle Chat podcast, Kansas State University Extension (KSU) specialists discussed how drought affects ponds, which provide water for many grazing cattle in Kansas. Find the podcast here: https://ksubci.org/…. There are several livestock health risks from ponds that are drying up.

Brian Lubbers, KSU Extension veterinarian, said as ponds start to get low water levels, cattle are often sourcing water from smaller access points. Producers should monitor this situation, he said.

"As ponds shrink, accessibility to the water can be an issue depending on the shape of the pond," Lubbers said. "Deep ponds can have steep sides that make it difficult for the cattle to reach and leave the water source."

KSU Extension Nutritionist Phillip Lancaster said one possible solution to problems when ponds dry up is to look at the grazing rotation of the herd. Be strategic when considering what pastures or rangeland to graze first in the grazing season, he said.

"Producers may need to graze a pasture with a pond earlier in the season to use that water source first, and then rotate cattle to other pastures that either have other water sources or are easier to haul water to," Lancaster said.


There are also water quality concerns as pond water becomes stagnant and levels drop. Producers should monitor water for nitrates and blue-green algae, according to the June UNL Beefwatch Newsletter posted by University of Nebraska-Lincoln (UNL) Extension: https://beef.unl.edu/….

Authors Troy Walz and Aaron Berger, UNL Extension educators, wrote if a problem is suspected with natural water sources, water should be tested to see if there are toxicity concerns. At the top of the list during drought is nitrate poisoning.

Livestock producers need to keep in mind the total intake limit for cattle is the combined amounts for both feed and water. Both feed and water nitrate levels may be in the acceptable range, but combined they could exceed recommended levels and cause toxicity problems.

A safe level of nitrate nitrogen (NO3N) in water for cattle is less than 100 parts per million (ppm). The upper limit for calves is less than 500 ppm, while for adult cattle the upper limit is less than 1,000 ppm.

"Symptoms of nitrate poisoning include brownish discoloration of the blood, difficult and rapid breathing, muscle tremors, low tolerance of exercise, incoordination, diarrhea, frequent urination, collapse and death," the report said.


North Dakota State University Veterinary Toxicologist Michelle Mostrom recommends livestock producers test their water sources for such items as total dissolved solids (TDS), sulfates and nitrates. TDS measures salt levels in water, she said. See her recommendations here: https://www.ndsu.edu/….

"Due to our geology in North Dakota, water with high TDS often have high sulfate levels," Mostrom said.

The term TDS often is used to reference the level of water salinity or the amount of salt in the water: https://www.ndsu.edu/….

Higher salt levels in water can lead to increased water consumption. Animals have different tolerances to salt content depending on species, age, season of the year and physiological condition.

Generally, animals will avoid high-saline water sources but will drink poor water if it is the only water source available. Signs of salt poisoning are weakness, dehydration, tremors, aimless wandering, ataxia (disorders that affect coordination and balance), seizure-like activity, partial paralysis and death.

Treatment options are focused on limiting access to only good quality water right away. Slowly return the animals to normal water hydration during a two- to three-day period.


Blue-green algae is toxic to cattle, according to the UNL BeefWatch report. This algae grows in stagnant water and looks like someone dumped a bucket of light green or turquoise paint in the water.

Blue-green algae is a known killer of cattle in South Dakota, according to a South Dakota University (SDSU) Extension report: https://extension.sdstate.edu/…. The report, written by SDSU Extension Cow-Calf Field Specialist Robin Salverson, said ingestion of toxic algae can kill an animal within 24 hours or less.

The algae bloom can come and go very quickly on the surface of water sources as a result of increased moisture and cooler temperatures. Detection of the algae blooms can be difficult, she wrote.

"Producers should be on the watch for bluish-green algae with the possibility of being dark green to brown in color during hot sunny days on surfaces of water that are stagnant," Salverson wrote.

Signs of blue-green algae poisoning are diarrhea, lack of coordination, labored breathing, seizures, convulsions and possibly death.

NDSU Extension had more information about water quality during times of drought. This information can be found at https://www.ndsu.edu/….

Russ Quinn can be reached at Russ.Quinn@dtn.com

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Russ Quinn