Low Stress Stockmanship means also balancing dark and light for dairy cow well-being
Light is good, but cows need darkness as a necessary.
Darkness provides not only necessary physiological benefits, it supporting both well-being (animal welfare), and milk production.
Cattle can perceive their surroundings at night even without light
Light in the cowshed at night is therefore not necessary for cattle.
That makes sense, in nature no one stands near the animals with a light...
At best, moonlight is the only source of light in nature.
During long summer days, naturally daylight increase milk yield, while short winter days slow the milk yield down
It is the hormone Melatonin, controlled by light exposure, that follows a strict day-night rhythm.
When cows perceive blue light, their melatonin production is suppressed.
During night and in complete darkness, melatonin levels rise. This fluctuation helps regulate the Insulin-like Growth Factor-1 (also known as IGF-1) from the liver, which contributes to increase the milk yield.
In case of exposure to nearly a constant 24-hour light schedule, the natural rhythm disrupts, suppressing melatonin and negating the benefits of a balanced light-dark cycle.
Without a proper dark period, the biological processes that enhance milk production and influenced wellbeing and animal welfare become imbalanced.
I recommend using a light clock to automate light schedules . This ensures consistent, optimized lighting patterns, keeping cows in a healthy and animal friendly routine.
16 hours of light alternated with 8 hours of darkness
Research and practical experience show that a 16-hour light and 8-hour dark cycle (16L:8D) is the most effective approach for lactating dairy cows. With this schedule, summer conditions are best approximated in terms of hours of light.
As a result, dairy cows benefit optimally from increased IGF-1 levels, while circadian rhythms remain stable.
Avoid shadows and dark spots in the cowshed, they can create stress
Install well-placed lighting of high quality and suitable for use in cowsheds, so that the barn is evenly lit.
At least 6-8 hours of darkness is essential for a good and accurate melatonin release.
Therefore, cowsheds should be dimmed to a maximum of 5 lux to achieve this process.
Source text and photos: Ronald Rongen