The lighting in your barn may be having more of an effect than you realize.
“The livestock’s biological clock is regulated by light striking the pituitary gland in the middle of the brain. A lack of light depresses metabolism and causes increased melatonin output. We see this effect in the shorter days of winter,” said Andrew Hannon, lighting solution specialist with Agrilight Inc., an expert lighting company that specializes in livestock barns and agricultural buildings.
Research has shown that a well-lit barn can both boost your bottom line by reducing energy costs and increase milk production.
“The benefits of proper barn lighting are that we can simulate and achieve a natural rhythm for the livestock in the barn. We want to manipulate that day, night rhythm,” Hannon said.
Independent research on the effects of lighting on dairy cattle began in 1978 at Michigan State University where researchers placed one group of dairy cows into 16 hours of light, followed by an eight-hour period of darkness and another group that was left at a natural light period during calving.
“The study was conducted between September and March and it took place over the first 100 days postpartum. Cows on a long day regime produced two litres per day more milk than those on the natural photoperiod,” Hannon said.
At 100 days the treatments were switched. The cows previously on a natural photoperiod increased in milk production when brought in to the long day light, where those that were on the supplemented lighting decreased their milk yield.
“The results suggested that exposure to long day lighting increases milk yield and it does so across the production level,” Hannon said.
Since this initial study, a number of similar studies have been conducted in North America and Europe and the response has been confirmed, the correct light intensity and duration have positive effects on the health, fertility, welfare and productivity of dairy cattle.
Researchers have found that light impacts hormone levels in cows and can increase milk productivity by 15 per cent.
“Based on those studies, the recommended long day lighting for both milking cows and growing heifers is a light intensity of 150 to 200 lux over a 16-hour period, followed by an eight-hour dark period with a light intensity less than 50 lux.”
This lighting equation simulates long summer days, the days the cow is naturally the most active, resulting in higher yields and higher feed intake.
“With that increase in feed intake and an adequate rest period, that long day lighting provides, the overall health of the cow is usually improved as it is less stressed, which in turn also helps improve fertility,” Hannon said.
What to consider
When looking at your facility and its lighting, there are a few things to take into account. Is the interior of the barn a reflective material? Plywood or concrete may require more lighting. As well, different areas of the barn require different light intensity.
“Veterinarian areas require very intense light levels because of the inspection required, whereas your feed alleys and sleeping pack areas require less intense light,” Hannon said.
When positioning lighting it is best to watch for posts, beams or anything that may cast irritating shadows.
“You do not want to put lights above ceiling fans. You will in effect create a strobe light, which is unsettling for, not just cows, but also all other livestock and people as well. Do not put lights over fans,” Hannon said.
“Other considerations that are very important are electrical considerations in general. Cows specifically are very sensitive to stray voltage and electrical noise can interfere with our RFID tag technology. So, things like grounding your electrical system become very important. It is amazing how low the voltage can be and a cow can detect that voltage. That is when you start to see cows not wanting to go to feeding troughs or other behavioural issues.”
When looking at different lighting options, Hannon says LED lights are the most popular in agricultural buildings because of the low energy use with virtually no maintenance.
“Florescent lights would be next most popular and they are very good energy consumption, efficiency-wise but have a high-maintenance factor,” Hannon said. “Then there are HID systems, which have a moderate or low efficiency on energy consumption. They are the highest burner of energy and they have a medium level of maintenance.”
Hannon also recommends light products that have damp or wet location ratings as they will last longer.