Dairy cows, environmentalists and budget-minded farmers can all get behind new research in LED technology.
It’s too early in the research to say for certain, but a 2010 Oklahoma State study comparing energy-saving LED to traditional light in dairies showed a 6 percent bump in milk production under LED, said Ron Kensinger, a professor of animal science there at the time of the study.
“The primary reason to do this is to save money,” said Ken-singer, chairman of the animal sciences department at Ohio State University.
“LED lights in the long term will conserve lot of energy, even if there’s no benefit to cows.”
LED (light-emitting diode) lights consume at least 75 percent less energy compared with conventional incandescent lights and last 25 times longer, although they cost more up front, according to the U.S. Department of Energy.
For the experiment, Kensinger said they split a 500-cow free-stall barn on a large commercial dairy in half — one side outfitted with LED lights and the control side with traditional metal halide lights.
It was conducted in late September, so the researchers expected a normal increase in milk production because of the drop in fall temperatures.
The control group went from 60.1 to 64.2 pounds of milk, while the LED group surprised them with a jump from 62 lbs. to 70 lbs.
“We know cows will respond to increased light,” Kensinger said.
LED lights have advantage of being more directional than traditional sources, especially in a high-ceiling barn.
“The key is to increase light intensity where you want it — in feeding and walkway alleys,” Kensinger said.
“You want the light where cows eat because greater light intensity and duration has been shown to increase feed intake.”
Greater feed intake could be one of the reasons the cows produced more under LED.
Kensinger said it also could have increased hormones that promote production, but at this point in the research, they can’t differentiate.
“The experiment really needs to be replicated,” Kensinger added. “There’s a big difference between trial-and error and truth.
“We need to replicate the study where we do determine exact feed intake. It’s important because farmers need to know what will it cost and the benefits.”
Geoff Dahl, chairman of the department of animal sciences at the University of Florida, said he’s wary of Oklahoma’s numbers, but optimistic about LED’s other advantages.
“The wavelength of light you get and the whiteness from LED should not have an influence,” he said.
Research has compared different kinds of light, such as fluorescent, incandescent and halogen, though not LED, and results showed all varieties have the same effect when you extend the photoperiod, Dahl said.
“It has an influence on secretion of a number of hormones — first, melatonin,” he explained.
“With increased light, we’re shifting the pattern on melatonin secretion and that affects other hormones down the line, like prolactin, which has to do with milk production.”
For further study on the LED effect, Dahl said researchers would have to pinpoint the intensity and duration of exposure for each light group to get an “apples to apples” comparison.
Faculty at the University of Missouri had pursued a grant from the USDA to continue the LED study, but found out this past week they won’t receive it this year.
Matt Waldron, an assistant professor of animal science there, said the results from the Oklahoma study are encouraging.
“There’s potential for it. It needs to be considered, and we need to get better research, get it replicated in multiple facilities,” Waldron said.
He was concerned with the quality of the conventional light in the Oklahoma study’s control group. He said Oklahoma researchers indicated the cows not under the LED lights were in a poorly lit area.
“The cows in conventional lighting were not under what we would recommend as far as strength of light and duration,” Waldron said.
But, Waldron said LED lights have other economic benefits, whether the boost in milk production holds in future studies or not.
“Overall with LED, when you look at longevity and operating cost, it’s going to be lower,” he said. “It’s going to be a good thing for a dairy and a good thing from an environmental standpoint. It could be positive whether you get production bump or not.”