When temperatures soar into the 90s, making sure cattle have enough water is critical, a North Dakota State University livestock expert says.

“Cattle can withstand a lot of high heat if there’s adequate water for them to drink,” adds Karl Hoppe, area Extension Service livestock specialist at the Carrington Research Extension Center.

Three factors producers need to remember are quantity, access and quality.

“Cattle can drink a lot of water during hot weather – 20 or more gallons a day,” Hoppe says.

They also may have trouble reaching the water in pastures because last year’s drought conditions lowered water tables and exposed unstable soil at the edge of ponds and dugouts.

Roxanne Johnson, NDSU Extension’s water quality associate, warns that green or blue-green algae may appear overnight on the surface of water and it may be fatal to livestock. Not all algae blooms are toxic, but identifying which ones are poisonous is impossible without laboratory analysis or finding small animals dead along the water’s edge. Warm weather, calm winds and abundant nutrients cause the algae, which actually is bacteria, to proliferate.

Hoppe suggests producers check their cattle’s water supplies frequently, not only in the pasture but in the feedlot.

“With 100-degree weather, checking water supplies on a daily basis may not be often enough,” he says.

Spring-fed ponds that have water one day may be dry the next day because the water table drops below the level of the pond, he notes. He says he also knows of instances of lightning strikes disabling solar-powered wells.

Another reason producers should check ponds and dugouts often is that cattle may want to swim in the water to cool off and they could get stuck in the mud, according to Hoppe.

Producers have a couple of options if their livestock’s water supply runs low – haul in water or move cattle to another water source. Hauling water can be costly, but making cattle walk to another pasture can be very stressful in high heat, Hoppe says.

If producers choose to haul in water and the containers they plan to use have held anything other than water, they must flush the containers at least once.

“Flushing the tank always is encouraged since even a small amount of fertilizer left in the tank can be fatal to livestock,” Hoppe says.

NDSU Extension livestock experts have this advice to help prevent water supplies from running low:

• Periodically clean and redig ponds and dugouts.
• Fence cattle out of ponds and dugouts and pump water to a tank.
• Allow livestock to have access to ponds and dugouts only at a sloped, graveled area.

Johnson advises producers to treat their pond or dugout water if they’ve previously had blooms. Treatments include using an aeration/mixing device to create turbulence in the water, treating the water with copper sulfate, pretreating with barley straw and establishing vegetated buffer strips around the water to intercept and trap nutrients and sediments to keep them out of the water.

Producers also should clean their stock tanks with a wire brush, followed by a thorough rinse with a power washer. This should be done on an annual basis to keep algae growth to a minimum, she says. Ways to control algae growth in stock tanks include adding a dilution of household chlorine, a solution containing zinc sulfate or a solution of copper sulfate to the water.

Strategies for reducing heat-related problems in cattle in feedlots include limiting their feed consumption, reducing the amount of energy in their diet, feeding them later in the day, spraying them with cool water and providing shade.

For more information on livestock water intake, signs of dehydration, water access and water quality issues, check out NDSU Extension Service publication AS-954, “Livestock and Water.” It’s available online at http://www.ag.ndsu.edu/pubs/ansci/livestoc/as954w.htm.

NDSU Agriculture Communication