Dairy farmers work to help cows stay cool


Issue Date: July 19, 2017
By Ching Lee
San Joaquin County dairy farmer Hank Van Exel checks on the mist that helps to cool his cows. Despite providing shade and using fans and misters to relieve their cows, California dairy farmers say they expect to lose some milk production due to triple-digit temperatures in recent weeks.
Photo/Ching Lee
During hot summer months, most California dairies employ fans, above, and misters, to keep their animals cool. The systems typically operate on timers and are set to kick on when temperatures reach a certain level.
Photo/Ching Lee
Misters, keep their animals cool. The systems typically operate on timers and are set to kick on when temperatures reach a certain level.
Photo/Ching Lee

Sweltering temperatures have slowed the flow of milk from California dairy cows, but analysts say it remains uncertain whether lower production from the nation's No. 1 dairy state will significantly buoy milk prices being weighed down by large inventories and other factors.

Milk production typically falls during summer months, as cows respond to the heat. Record-setting heat in June had fans and misters at dairies turning on early and working overtime to cool cows.

San Joaquin County dairy farmer Hank Van Exel said his cows probably produced about 15 percent less milk during the June heat wave, and triple-digit temperatures this month have not helped to stabilize production. He said some of the same cows that were affected by the June heat also showed effects of the more recent high temperatures.

"It's not going to be easy for them to get back to where they were," he said. "They probably will not get back, and then their production curve for the rest of the year is lower."

During extreme heat, cows eat less and drink more water, he said, reducing not only the amount of milk they produce but also components such as milkfat and solids.

If milk components take a big hit, it could affect production of dairy products such as butter and cheese, said Katelyn McCullock, an economist with the American Farm Bureau Federation, noting the Golden State produces 20 percent of the nation's milk, more than 30 percent of the butter and 8 percent of U.S. cheese.

Lower yields of dairy products, she added, could boost demand for milk, as it will take more milk to produce the same amount of cheese and butter.

Higher summer production of ice cream also reduces the amount of milk that goes into making butter, raising demand for milk, Fresno County dairy farmer Donny Rollin said.

"However, let's not bet the farm that higher milk prices will follow," McCullock said, adding that U.S. butter and cheese stocks are still "at fairly high levels on a historical basis" and butter exports have lagged this year.

Van Exel said while he hopes any reduced milk production in the state will have a positive effect on the overall market, it will likely be offset by other milk-producing regions that have continued to increase production.

Rollin said the heat spell in June "hit me pretty hard," but noted his cows have since bounced back and are now "milking well and eating well." He said he had not seen any heat-related cow deaths on his dairy and neither had dairy farmers he's talked to.

"I think guys have learned how to cool cows," he said. "We know how to take care of them. This (heat) isn't any different for me than previous Junes or Julys that have been hot."

Peter Robinson, a University of California Cooperative Extension dairy nutrition and management specialist, said a heat wave for this time of year is characterized by at least three nights of temperatures hovering above 80 degrees.

"That's when the real trouble starts, because then the cows can't disperse heat during the nighttime," he said.

Milk production on California dairies definitely took a hit during the weeklong hot spell in June, he said, with cow feed intake off by 5 to 10 percent on the low end and 25 to 30 percent on the high end for older dry-lot dairies that don't have cooling systems, though those facilities are now rare in California.

Typically, when a cow's feed intake drops by 10 percent, it is expected that her milk production will go down by 5 to 6 percent, he added. Cows will also mobilize more fat from their bodies to produce milk, which will affect their breeding performance. Some cows that were inseminated during the high-heat period in June did experience a lower breeding percentage, he noted.

But Robinson said he doesn't think the June heat had much impact on the overall supply of milk in the market, as production impacts were "relatively small."

"We are much less affected in California by extreme heat today than we were 20 years ago, and the reason for that is farmers have put in a lot more heat-abatement equipment" such as fans, misters and soakers, he said.

Farmers have also changed how they deal with heat, he added. Years ago, they were more inclined to manage their herds when they got hot, typically by adjusting their feeds. But now farmers try to prevent their cows from getting hot. They learned that changing the cow's diet—often by reducing the fiber level and raising the nonstructural carbohydrates to achieve a higher-density feed—created a nutritional imbalance that made cows more susceptible to acidosis and other negative impacts.

Dairies in the South and Midwest, he noted, often have a tougher time with heat because they are also dealing with humidity, making evaporative-cooling methods such as misting less effective.

"Those dairies are smaller and don't have the cooling capacity," Robinson said. "Their milk production goes down a lot more than ours."

Hot, dry weather in other parts of the nation will also affect dairy markets.

Joel Karlin, market analyst for Western Milling in Goshen, said he's much more concerned about the bullish impact conditions in the nation's midsection will have on feed prices.

"I think our corn and soybean crops are in big trouble," he said. "We're facing the most stressful conditions in five years."

A large part of the Great Plains and the western Corn Belt have been afflicted by high temperatures and below-normal rainfall, he noted—and at a time when the corn crop is pollinating and has the highest water requirements.

"Having said that, we're not going to get a full-blown price rally because we have plenty of stocks both here, abroad and in the bin," he added.

With ample U.S. and world supplies of oilseeds and grain, Karlin said production could be cut "fairly substantially before you have an appreciably higher market."

(Ching Lee is an assistant editor of Ag Alert. She may be contacted at clee@cfbf.com.)

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.