During last year’s heat wave in California, dairyman Greg Anema of Ontario, California discovered the two coolest places on his dairy – the breezeway in his parlor and a kiddie pool under a shade tree close to the milk barn. He also found out how his cows try to cool off. “I’ve got young children and while they were playing in the hose I jumped in,” Anema says. “It was a way to just try to cool off.”

The more than 1,600 cows at Anema’s Jorritsma Dairy also headed for water. While other large-herd dairies lost more than a dozen animals during the record-setting heat, Anema lost only three cows.

“Traditionally, you put the vitamins and trace minerals in the TMR,” Anema says. But for the past two years, Anema has been adding vitamins and minerals to his water, injecting his well water with chlorine dioxide to kill bacteria and frequently testing his water for quality.

“Herd health wise I did a little bit better than I otherwise would have,” Anema says.

He says his experimenting with water quality has taught him the importance that cows place on its quality, as much or more so than its availability.


“I’ve just noticed that since we’ve been treating our water we’ve had improved reproduction and improved overall herd health. It’s another tool to do a better job with your animals,” Anema says.

Here are some of the other lessons Anema said he learned during the crucible of last summer’s heat stress:

• Try to do the best you can to cover stanchion lines with shades and misters.

• Although feed consumption dropped by as much as 10 pounds, cows continued to consume water (30 to 31 gallons).

• Groom dry lot corrals every other day.

• If you are heading through a period of short-lived heat stress, back off some of the normal routines you may perform that may cause additional stress such as prolonged lockups, vaccinations or hoof trimming.

• It’s going to be rough for employees, too. Keep the fans and misters blowing inside the parlor.

• Gear your employees up for the heat. Keep them focused and positive.

• Feed late in the evening. Ask feeders to come in earlier, take more time off during the day and come back to feed again late in the evening. Tell employees why they need to feed early in the morning and late in the evening (i.e., cows want to eat more during these times).

• Don’t take on new projects.

• Offer to help out with chores that require physical labor. Don’t make one guy do a difficult job in the heat by himself.

• Water quality can change from month to month. Test frequently.

• Drench all the fresh cows for a day or two right after they calve.

• In hospital pens, instead of locking up all the cows in a pen, watch for cows that aren’t eating at all. Treat them on an individual basis. PD