Strange enough, I get a lot of questions about lighting in livestock housing during seminars, practical training sessions and workshops in autumn and winter. I deliberately call it “ strange enough,” because even in the summer many livestock houses are too dark.
The reason for this is often cost savings. But this cost savings may not only have a negative impact on animal welfare of the animals present in the barns, it may also have a negative impact on production characteristics. For example, daily growth, milk yield, development, fertility, et cetera. Light stimulates growth and well-being, not only in plants but also in animals and even in humans!
Good lighting is therefore essential.
Light color, light distribution and light intensity as well as the total number of lighting hours and the number of hours that artificial light is used, it all affects animal behavior and therefore their welfare.
THE IMPACT OF LIGHT ON THE FUNCTIONALITY OF LACTATING COWS
Light captured by the retina REDUCES the production of the hormone melatonin. Melatonin will make cows less active.
Less Melatonin secretion thus increases the cow's productive capacity by increasing the production of the hormone IGF-I and releasing it into the blood. The IGF-I, in turn, stimulates the cow's activity and therefore her milk production.
THE EFFECT OF LIGHT ON THE FUNCTIONALITY OF DRY COWS
For dry cows, the best light program is 8 hours light and 16 hours dark. Then the cow produces MORE melatonin, which stimulates resting.
THE EFFECT OF LIGHT ON THE DEVELOPMENT OF YOUNG STOCK
Light stimulates growth and physical development, which can reduce the gestation period by up to 4 weeks.
We also see that the time between calving and first insemination can be shortened with the right light regime and lighting.
The fertility cycle can thus be “restarted” more quickly. This usually works best at first-calf cows and a low-quality ration.
TOO MUCH IS NOT A GOOD THING EITHER
If you illuminate too many hours, it will have negative effects on coming into heat and showing heat symptoms.
By lighting the foraging areas significantly brighter you create a visual incentive to come to the foraging area, (by the way: light does NOT affect foraging speed).
DAY AND NIGHT RHYTHM IN THE COWSHED
Animals also benefit from an optimal day and night rhythm.
For lactating cows, this means 16 hours a day light followed by 8 hours of darkness.
This light regime not only shortens the intermediate calving period, it also increases disease resistance.
THE INTENSITY OF LIGHT
The light intensity due to indirect sunlight on a sunny day range from 10,000 lux to more than 20,000 lux.
To have good daylight conditions in cow barns, it is important to achieve at least 250 lux at 60cm above the floor.
In doing so, avoid dark areas and shadows. Cows see these as “black spots” and therefore as a potential threat!
LAST BUT NOT LEAST, THE COLOR OF THE LIGHT
The color temperature of light is indicated in Kelvin (or by the letter K).
The higher the number of Kelvin, the “ cooler” or “whiter” the color of the light.
Ideally, you should have a light color that approaches daylight as much as possible, (white full-spectrum daylight has 6500K).
This white full-spectrum daylight is for lactating cows housed in a barn the best light in terms of replicating daylight.
Source text and photos: Ronald Rongen, Infographic: Tony Butler