Long Day Lighting in Dairy Barns

One question we are often asked is, “is my barn too dark?” Our honest answer? Probably. Read on to learn more and to get our tips for brightening up your barn.


Dairy Barn Lighting

Many, if not most, barns are too dark, clocking less than 12 hours of daylight each day. Studies over the last few decades, across varying climates, have proven that increasing day lighting in dairy barns to 16-18 hours per day can improve a variety of important dairy farm metrics. Having different photoperiods at different stages in a cow’s life has also proven to be beneficial.


Improved Milk Production

One of the largest impacts you’ll notice when utilizing long-day lighting in your dairy barn is an increase in milk production. According to research done on the subject, cows exposed to 16-18 hours of day lighting produced, on average, 4-5 additional pounds of milk per day. This increase is experienced when the average light intensity is at least 15 foot-candles at the cows’ eye level.

 The science behind it is simple and scientifically-proven; when it’s dark, cows produce melatonin, which regulates their internal clocks. Melatonin can also negatively impact milk production. By contrast, long-day lighting increases IGF-I (insulin-like growth factor), which in turn increases milk production.


Safer Staff

Trivial, easy-to-avoid accidents often happen to staff as they perform their daily barn duties. A simple way to create a safer environment for all involved is to ensure adequate lighting throughout the barn. Proper lighting can help your staff avoid obstacles, slippery surfaces, and other hazards that can cause injuries. Unlike cows who can still find their feed and water in the dark, humans have a hard time navigating it. Studies have shown that having low-intensity red lighting is useful for employees, and does not disrupt the cow’s photoperiod.


Safer Herd

With long-day lighting, you and your staff will also be able to keep a better eye on your herd. Good lighting will help you notice and identify any cows in heat, off feed, with health problems, and more. You will also want to note that dry cows will have the opposite effect with long day photoperiod compared to cows that are lactating.


Consistency is Key

When utilizing long-day lighting, it’s important to adhere to a strict, consistent schedule. The ideal number of day lighting is 16-18 hours, with 6-8 hours of darkness. Sticking to a schedule is the best way to ensure improved milk production. Starting to manage light at a cow’s young age is beneficial for consistency throughout life.


We offer a variety of cost-effective solutions for those looking to incorporate long-day lighting. Learn more here!


[Some information from this article is obtained from “The Effects of Lighting Manipulation on Dairy Cattle Management” by Derek Nolan, Donna Amaral-Phillips, Ph.D & Jeffery Bewley, Ph.D]