Released: May 16, 2002

Also see: June 2002 Dairy Month news package

K-State Testing Cooling System for Dairy Cows

MANHATTAN, Kan. – Cool cows are productive cows.

And, some dairy farmers would likely say, productive cows are pretty cool, too.

That’s why researchers at Kansas State University are studying ways to help dairy cows beat the heat. They’re planning on-farm trials this summer to confirm preliminary findings that wetting dairy cows more frequently is the key to keeping them comfortable.

"If [farmers] can do only one thing to reduce heat stress, then wetting those cows more frequently is better than installing more fans," said Mike Brouk, an animal scientist with K-State Research and Extension.

Brouk is part of the research team that tested the benefits of wetting dairy cows on the feed line and in the holding pens. He said the researchers tested 5-, 10- and 15-minute wetting cycles, which he admits "is a lot of water."

But now the researchers are looking at "strategically placing these wetting cycles throughout the day" in combination with fans and between times when cows are lying down. K-State engineer Joe Harner said the researchers want to develop recommendations for controlling the system at times when the cows are not at the feeding line.

"Based on our summer field trials, we may be able to turn out [recommendations] by next fall," Brouk said.

So far, K-State’s research has shown that wetting in five-minute intervals can reduce the cow’s respiration rate from 100 to 50 breaths per minutes. Brouk said the level at which a dairy cow is "stressing" and production is down is 80 breaths per minute.

Wetting cows is intended to drop their skin and body temperature, according to Brouk, who said a farmer’s best strategy is to combine frequent wetting with supplemental air flow (fans). Most wetting systems use overhead sprinklers that spray a mist of water on the cow’s back.

Harner said K-State’s work is based on previous research related to heat abatement in Florida and Arizona.

"The field data has consistently shown a positive rate of return during the first year of operation of the systems because of improvements in cow comfort and milk production," Harner said. In fact, "if done correctly, there is a positive net return; installing a partial system may result in limited return."

Harner added that field trials have helped the K-State researchers develop fan and sprinkler configurations that are "optimal" for this region.

K-State is planning cost-efficiency studies, but because the start-up cost is relatively low, it is a system that is affordable for both small and large operations.

"Some operations may not be able to take advantage of the systems due to the fact that their facilities are older," Harner said. "[For example] fans cannot be installed in the housing area or over the feedline...so the full benefit cannot be obtained."

In older facilities, producers still can help cows avoid heat stress by providing adequate shade, reducing time in the holding pen, soaking cows exiting the milk parlor, and adjusting feed and milk schedules.

Brouk said additional research at K-State is looking at tunnel-ventilated facilities (particularly in western Kansas), and possibly incorporating a high-pressure fogging or high-moisture evaporative system with high-frequency wetting.

For more information, interested persons can contact their local Extension office.

-30-

K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.

Story by:
Pat Melgares, News Coordinator
pmelgare@oznet.ksu.edu
K-State Research& Extension News