Shedding Light on More Productive Cows

3/9/2013 7:00 AM
By Paul Post New York Correspondent

BALLSTON SPA, N.Y. — “Let there be light!”

It must be pretty important because it’s the first thing God created, after the heavens and earth, the Book of Genesis says.

However, dairy cows sometimes don’t get enough of it, especially in winter, which can impact production levels considerably.

“You should be trying to simulate June 21, the longest day of the year,” said Jackson Wright, a Cornell Cooperative Extension dairy specialist. “That’s essentially what we’re shooting for.”

He was one of several Extension agents who conducted workshops for more than two dozen farmers at a winter dairy management event called “Managing Your Dairy for Resiliency” on Feb. 27 in Ballston Spa, N.Y.

“If we increase light exposure to cows, we can increased production up to 10 percent in some cases,” Wright said.

Briefly, he outlined the science behind light’s impact biologically, a phenomenon called Circadian Rhythms. Quite simply, various bodily functions reach their peak at different times of day, depending on the amount of light a person or animal is exposed to.

Light decreases the amount of melatonin, a sleep enhancer, in the body. So farmers should be trying to get cows on a regular cycle of 16 to 18 hours of light and six to eight hours of darkness each day.

Wright then discussed the pros and cons of different lighting systems — T8 fluorescent, high-intensity discharge and light emitting diodes (LED).

For example, fluorescent lights are efficient and relatively inexpensive, but they also contain mercury. If one breaks, the entire milk supply could be compromised, a major safety, public relations and financial setback. They also have to be replaced more frequently.

Also, their light output goes down in cold weather.

High-intensity fixtures work well even at tall heights, but take time to start up and have a limited light spectrum. LEDs are efficient, require little maintenance and work well in extreme cold, but are more expensive than other lights.

Regardless of the type chosen, proper installation is essential.

Lights must be properly spaced to ensure that the entire barn area is covered, not just directly beneath the fixture.

“It has to be well thought out,” Wright said.

Wright said one farm in Missouri realized a 6 percent increase in production by installing LED lights.

However, every farm setting is different. Barns have different heights and sizes, climate varies from state to state and more research is needed about the wavelengths produced by different types of lights.

In short, lights might not produce the same results for one farm as they do another, and the jury is still out regarding which type of lighting helps cows most.

“I don’t think there is necessarily a best’ at this point,” Wright said. “But it’s worth exploring.”

Engineering students at Rensselaer Polytechnic Institute in Troy, N.Y., have worked on a project using a dimesimeter, a small light meter that’s placed on a cow’s ear tag.

By placing three different types of lights in three barns that have the same management and farm practices, researchers hope to discover which system is the most effective.

Of course, regardless of their impact on milk production, new lights have another distinct advantage.

“With the new technology that’s out there we can also reduce energy costs,” Wright said.

Farms considering a new lighting system may find helpful information from the Design Lighting Consortium, a group dedicated to raising awareness about the benefits of efficient lighting in commercial buildings. For information, visit For information about LED lights, visit

Do the deer cause a lot of damage to the fruit and vegetable crops in your area?

  • Yes
  • No
  • Unsure

User Submitted Photos

View photos      Submit your photos

  Ag Markets at Lancaster Farming

2/6/2016 | Last Updated: 7:45 PM