By Dwight Roseler
CANTON, Ohio — A good coach will prepare his team for the next competitor. Cows are great athletes, so as a dairy manager, you are a cow coach and need to prepare your cows for the summer season.
Hot to us and hot to a cow are two different temperatures. If they had the choice, dairy cows would set the thermostats in their barns around 55 degrees, with a range of 41 degrees to 68 degrees. Above 68 degrees, they begin to alter their eating and behavior patterns to reduce body heat, similar to what we might do when it is 95 degrees.
Does it pay to cool your cows? “Forty percent of the time in northeastern Ohio from May to September, the temperature is above where a dairy cow likes it,” said John Smith of Kansas State University, speaking March 11 in Canton at a dairy producer meeting sponsored by Land O’Lakes Purina Feed.
Approximately 85 people attended the dairy management workshop.
Research Smith conducted at various locations across the United States, including Ohio, has proven the benefit of installing fans, water sprinklers and cooling pads to improve a dairy cows comfort when it is above 75 degrees in the barn.
A cow is like a furnace — she eats around 100 pounds of feed a day to produce 85+ pounds of high quality milk a day. As she eats this feed, she also produces heat. When she cannot get rid of the heat, she will reduce her intake, stand up more or both. Eating less and standing more cause cow health and performance challenges.
Drinking water availability is critical for hot weather.
“Cows need at least 25 feet of liner water space per 100 cows in the summer,” Smith said, adding if your cows have to stand in line to drink, it will reduce performance.
The priority area to install fans and sprinklers is the parlor holding pen, then the prefresh pen, exit lane soakers, then the high cow groups and the remaining cow groups, Smith said.
The normal body temperature of a dairy cow is 101.3 degrees, with a normal respiration rate of 50 breaths per minute.
A body temperature increase of 1 degree (more than 102.3 degrees) around the time of insemination will lower conception rate by up to 13 percent, according to John Mahoney, DVM, a speaker with the Land O’ Lakes Purina veterinary services team.
Cows that are breathing in excess of 65 breaths per minute will have elevated body temperatures, which will lower not only milk production but also conception rate.
“Summertime pregnancy rates are almost doubled and fewer sole abscesses are present where proper fans and soakers are installed in our barns,” Kansas State’s Smith said.
The newest design in dairy cattle cooling is enclosed cross-ventilated barns with evaporative cooling pads, forced air ventilation, and down baffles for proper air flow.
Smith indicated the benefits of the cross-ventilated barns in the humid Midwest are less than when these barns are built in arid conditions, but his video of barn audits with indwelling body temperature probes indicated lower body temperatures in high-producing dairy cows housed even under humid Midwest conditions.
Summer feeding of high-producing dairy cows has also undergone new concepts.
Many proven feeding technologies are available that can improve summer performance of dairy cows such as fat feeding, amino acid balancing, Metabolizable Protein (MP) balancing, mineral nutrition, water feeding, DCAD formulations, and starch rate technology.
Some of these were discussed at the seminar and are available only through patented formulation systems. And, the speakers emphasized, new feeding technology is only as good as the housing program that goes with the technology.
What does this cooling technology cost? — a common question asked during the Land O’Lakes three-day seminar that covered two presentations in Ohio and one in Michigan.
Dr. Smith’s response: “If you can afford to lose 5 to 8 pounds of milk per cow per day in summer, then you do not need cow cooling.”
He said it with a smile on his face, as he knows that cow cooling really pays. Return on invested capital is often a payback of several weeks or months versus some capital investments that take several years to pay back.
(The author is a dairy technical manager at Land O’Lakes.)