Grazing cows produce 5 lbs more milk per day. Charles Fletcher of Washburn, MO, believes his hard-working Holsteins deserve some time in the shade during hot summer days.
Last spring, Fletcher designed and built a 20 x 20' portable shade for his cows on intensively grazed pastures. Covered with Mylar mesh panels that screen out 85% of the sunlight, the structure also includes a bracket to hold an automatic waterer. His cows' performance convinced Fletcher to build two more.
"In extremely hot weather, cows with shade produced nearly 5 lbs more milk per day," he says. "One shade this size will accommodate about 35 cows on grass. I wanted to provide shade for all 90 cows we're milking."
Fletcher uses 2" steel square beam to weld together the main 8 x 20' shade frame. Six-foot-wide hinged wings on either side are fashioned from 1" material. When the wings are extended, the portable shade blocks the sun from a 20 x 20' area. With wings folded down, the structure is a road-legal 8' wide. He mounts the frame on a boat-trailer axle and wheels for portability.
"I welded trailer hitches on the front and back of the shade," he explains. "This way, I can hook two or more shades in tandem and move them with an ATV. My grazing paddocks are strung out for a mile, from one end to the other. I needed something that would be easy and simple to move.
"I have about $2,000 invested in each shade, including the waterer," he adds. "That sounds like a lot of money, but with 5 lbs more milk/cow/day, it doesn't take long to recover that investment."
Fletcher moves his cows to new grass twice each day, after morning and evening milkings. He has installed above-ground water lines with quick-connect couplings along fence lines separating paddocks. When he moves a portable shade, he simply attaches a hose to connect the shade's waterer to the water line.
The dairyman also ran a small water line to sprinkler nozzles along the top of the shade. On days when temperatures get to 95 or above, he turns on the sprinklers.
"These nozzles put out small droplets, not a mist," he says. "You have to soak a cow's hair to get much evaporative cooling effect. This winter, I'm going to rig battery-powered timers to turn sprinklers on and off. I'll have to experiment some next summer to learn the timing interval needed."
Managing temporary shade took a bit of experimenting, too.
"The trick is to locate the shade in the pasture before temperatures get too hot," he has learned. "This way, about half of the cows will be under the shade at any given time, while the other half are grazing. If you wait and move in the shade when it's hot, cows tend to bunch up under it."
He says dairy cows can benefit from shade anytime temperatures get to 85 or above.
"In this area, shade is worthwhile for 100 days or more each year."
Fletcher tries to set a good table for his Holsteins. Orchardgrass, annual rye and matua bromegrass are the principal cool-season forages. For warm-weather grazing, he seeds Red River crabgrass, pearl millet and sometimes corn.
"I plant corn as a transition crop when I renovate pastures," he says. "Last summer I took out a bermudagrass stand and put in corn in three plantings about a week apart. I estimate the corn was worth $300 gross income per acre."