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Reduce Heat Stress In Dairy Cattle

Take steps to mitigate financial impact on dairy cattle operation.

Mindy Ward, Editor, Missouri Ruralist

May 31, 2013

3 Min Read

With the dog days of summer just around the corner, now is the time to minimize the amount of heat stress felt by both dairy cattle and dairy producer.

Heat stress is costly. According to an article in the Journal of Dairy Science, heat stress costs the dairy cattle industry up to $900 million. But the numbers could be even higher according to an article in Dairy Herd Management. It reports the cost of heat stress on the dairy industry could reach $5 billion. How low or high that number goes depends on how hot and humid our summer days will get this year.


Dr. Jamie Jarrett, dairy nutritionist with Purina Animal Nutrition LLC reminds dairy farmers that at 72 degrees Fahrenheit, most people are comfortable, but that is the breaking point for adverse effects depending upon the humidity level.

"We need to change our mindset in how we think about heat stress," she said in a news release.

To help dairy producers understand what the impact heat stress is having on specific operations, Jarrett shares that heat stress can cause a farm to lose 10% to 35% of an animal's current milk production.~~~PAGE_BREAK_HERE~~~

For example, Jarrett shows that a cow producing 100 pounds of milk in thermal neutral conditions could drop to 90 pounds of milk for a 10% loss or 65 pounds of milk for a 35% loss. If the milk price is $16 per hundredweight, the reduction to 90 pounds of milk equates to a loss of $1.60 per cow per day. The reduction to 65 pounds per day of milk equates to a loss of $5.60 per cow per day.

Extrapolate this across a herd of 500 cows, they are looking at a loss of anywhere from $800 to $2,800 per day.

But heat stress is not just a one day occurrence

Last summer was excessively hot for weeks on end in the Midwest states. Jarrett says if a cow suffered heat stress for a period of 45 days; the losses for a 500-cow herd grow to $36,000 to $126,000.

"When we put financials behind these percentages the losses an individual operation is facing start to become very real," she adds.

Help beat the heat

Jarrett offers this advice to combat the financial impact of heat stress:

* Invest in shade, fans and sprinklers for both the lactating herd and dry cows, most specifically close-up cows.

* Take steps to keep the holding pen cool.

* Provide plenty of water.

* Choose a highly palatable energy source.

* Double check your trace mineral and macro mineral levels.

* Raise dietary cation anion difference or DCAD levels to account for warmer weather.

Source: Purina

About the Author(s)

Mindy Ward

Editor, Missouri Ruralist

Mindy resides on a small farm just outside of Holstein, Mo, about 80 miles southwest of St. Louis.

After graduating from the University of Missouri-Columbia with a bachelor’s degree in agricultural journalism, she worked briefly at a public relations firm in Kansas City. Her husband’s career led the couple north to Minnesota.

There, she reported on large-scale production of corn, soybeans, sugar beets, and dairy, as well as, biofuels for The Land. After 10 years, the couple returned to Missouri and she began covering agriculture in the Show-Me State.

“In all my 15 years of writing about agriculture, I have found some of the most progressive thinkers are farmers,” she says. “They are constantly searching for ways to do more with less, improve their land and leave their legacy to the next generation.”

Mindy and her husband, Stacy, together with their daughters, Elisa and Cassidy, operate Showtime Farms in southern Warren County. The family spends a great deal of time caring for and showing Dorset, Oxford and crossbred sheep.

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