The amount of light a cow is exposed to has a significant effect on their biological clock. Cows exposed to long-day lighting tend to produce more milk, eat more feed, and maintain better overall performance compared to those in low-light conditions. However, cows at different stages of lactation have different lighting recommendations. For lactating cows, the long day photo period (LDPP) recommendation consists of 16 to 18 hours of light at an intensity of 150 to 200 lux, followed by six to eight hours of uninterrupted darkness. “LDPP promotes higher feed intake and stimulates hormonal changes that support lactation, including increased levels of insulin growth factor 1 (IGF-1) and prolactin while reducing melatonin secretion,” noted Akdeniz and Ullness.
While lactating cows benefit from extended daylight hours, the lighting protocol for dry cows looks a little different. “Short-day lighting (eight hours of light, 16 hours of dark) is recommended for dry cows, aiding mammary gland development, which supports higher future milk yields,” they said. About 60 days before calving, consider making the switch over to LDPP to prepare them for lactation.
But, what’s the best lighting to install? LED fixtures have quickly become the gold standard for barn lighting because of their durability, energy efficiency, and ability to maintain their brightness for tens of thousands of hours. LED arrays, like the AGM3 Peak Array, are often used in modern barns for their ability to direct light evenly and dim automatically for nighttime hours, as well as their potential to deter birds. Fluorescent fixtures may still be used in some facilities but have proven to be less efficient and also to have shorter lifespans. Ullness and Akdeniz recommend evenly spacing lighting fixtures to create more uniform lighting, and placement levels of at least 10 to 12 feet above the cows to create less glare and shadows.
If you are looking to better manage not only electricity use but to capitalize on the profitability of your herd, take a look at your lighting setup. “Overall, the data suggested that naturally or hybrid ventilated barns provide better natural lighting conditions, contributing to energy savings by reducing the need for artificial lighting. Given that Wisconsin experiences sunny or partly sunny conditions for nearly half the year, ranging from 185 to 190 days, installing skylights or transparent sidewalls and keeping them clean can significantly reduce energy use,” the authors explained.
