The Science of Swine Lighting
ONCE® lighting systems are designed to provide exceptional light quality for both the swine herds and humans caring for them. They are made with species-specific, Dim-to-Red Technology and are suitable for use in sow barns, gestation buildings, nurseries, gilt development units and finishing facilities. Our technology allows the lighting fixture to fully dim red, which swine perceive as darkness. This allows the red light to be used as a “service light” so workers can access the facility without disturbing or interrupting the sleep cycles of the animal.
The Effect of Lighting Indoors
The light we see affects our mind and a wide variety of metabolic processes within our body. Eyes are undeniably one of our most important organs. It is where light penetrates the retina and stimulates multiple biological functions. The light we perceive is part of the electromagnetic spectrum our eyes can detect, known as the visible spectrum. There are several aspects of artificial light important to swine producers:
- Spectral composition: The distribution of light wavelengths (indicates how much of each color is present)
- Photoperiod: The number of hours of light and dark in a 24-hour period
- Light intensity: The total amount of luminous power produced in the visual part of the light spectrum
Using an inappropriate artificial light, or simply improperly measured light intensities, will result in the illuminance (footcandle, lux) being too high or too low. The consequences of inappropriate lighting may affect health, production and welfare of your animals due to the abnormal light-induced biological responses.
Swine See Differently
Swine see colors much more subdued than humans do. They are dichromatic, meaning they have only 2 pigment cones and can only see two distinct colors, blue and green, with green being the more sensitive. The graphs below show the typical color sensitivity of a human eye compared to the sensitivity of a typical swine eye. In the Human Eye Spectrum (left) the highest sensitivity is in green and yellow, showing that humans do not see blue and red as well. In the swine spectrum (right), it is demonstrating that the eye is least sensitive to the color red.
Additional Resources on The Science of Swine Lighting
The Science of Swine Vision white paper, a PDF download
Building a Modern Pig Barn
Improve Animal Welfare
ONCE® lighting systems are designed to minimize extreme changes in lighting and positively directing animal behavior to reduce stress and improve their livability and performance. Abrupt changes are shown to excite animals, increase mortality rates, cortisol levels and inhibit melatonin secretion—all of which have a negative effect on their well-being. Sunrise and sunset simulation eliminates the stress inputs of switching lights on and off abruptly, supporting an animal’s immune response. By offering LED fixtures that present uniform coverage and a consistent light pattern, corticosterone levels are minimized and animal welfare is improved.
There are two major forms of domestic pigs, a European wild boar (Sus scrofa) and an Asian wild board (Sus indicus), however it is well documented that Asian pigs were used to improve European pig breeds during the 18th and early 19th centuries. Where swine originate is relevant to an animals’ natural habitat, which was meant to be outside. More specifically, the natural habitat of wild pigs is covered foliage and in natural settings, pigs are termed “crepuscular” in behavior — being active in the early morning and late evening (Lewis & Southern, 2001). Knowing this, we can create an enhanced natural environment where photoperiods are not as drastic and light intensities and spectrum are similar to what they originally experienced and perform best at.
Learn more in The Origin of the Domestic Pig: Independent Domestication and Subsequent Introgression case study.
Remembering back to the beginning, when it was a natural part of life for every living creature to experience a morning sunrise and an evening sunset, is the reason we focus on perfecting the science of animal-centric lighting with our mission to: Improve animal health through applied photo-biology.
Sunset and Sunrise
The circadian pacemaker consists of two component oscillators. One is entrained to dusk and controls the onset of melatonin secretion. The second is entrained to dawn and controls the melatonin amplitude. The natural daylight spectrum during sunsets and sunrises is different from natural light at noon. There are also significant seasonal variances in the spectral composition of sunset and sunrise light.
Birds react not only to seasonal changes in daylength, but also seasonal changes in the light spectrum. These facts add to the importance of considering spectrum in the addition of sunrise/sunset controls in artificial lighting choices. The second picture on your right illustrates the typical spectrum of a summer sunset.
In the spectrum charts below, daylight at noon is compared to daylight at sunset is compared.
Significance of Light on Swine
The Importance of Light Color
Pigs have dichromatic vision; in the pig’s eye there are two sets of cones that give the animal peak wavelength sensitivity at 439 nm (blue color) and 556 nm (green color). The photoreceptors in a pig’s eye cannot detect the color red (>650 nm). Past research indicates that in order to get a physiological response from domestic pigs, the light exposure for “daylight” should be within the light spectrum of 380 to 580 nm.
Recommendations for Light Intensity
Research by Tast et al. (2002) found in pigs there was a melatonin response to light at intensity as low as 40 lux. When changing abruptly from short to long days however, Tast suggested higher intensities (> 240 lux) be used to suppress the established melatonin rhythms. It is important to note that Tast’s scotophase (levels of light during the night phase) was 7 lux , since light during the night phase must also be considered in lighting programs for boars.
Significance of Photoperiod
Photoperiods can be separated into three components 1) length of time there is illumination in a 24- hour cycle (photoperiod length); 2) the direction (increasing or decreasing) of change over time in the illumination period; and 3) the time increments involved in the change of illumination over a specific time.
Findings for gilt development and gestation lighting shows that a daily photoperiod of 12 to 18 hours in length followed by a period of at least 6 hours darkness (red) is most beneficial, while 15 to 18 hours is recommended for farrowing room lighting. Lighting for nursery and finishing rooms recommend 8 hours of complete darkness, with a 30-minute sunrise/sunset simulation to reduce stress caused by the abrupt change from dark to light and vice versa.
Learn more about the three components in The Science of Swine Vision white paper, a PDF download
Experience a Return-On-Investment
When applied properly, lighting can greatly enhance performance and therefore profitability. A lighting system in a barn has three characteristics–color of the light (wavelength), intensity of the light, and the amount of time the lights are on each day (daily photoperiod). With advancing LED technologies, farmers can now simultaneously vary the color, intensity and photoperiod of the lighting in animal houses and barns.
The Right Lighting Program
Studies have proven that choosing ONCE® swine-specific LEDs supplied with a recommended light schedule can have a major impact on pre-wean mortality and animal welfare. For example, a lighting program for farrowing rooms recommends 15 to 18 hours, which has been proven to encourage increased suckling activity and improvements to milk composition, resulting in larger, heavier litters at weaning.
Want to learn more? ONCE® has a team of experts who know the best solutions specific to you and your animals. They make sure you get a lighting layout with the correct light levels and placement of the lights, for free! They can also help answer questions about lighting schedules and surge protectors as well. Contact someone on our Layer team today to learn more about what the right lighting program can do for you:
+1 (763) 381-5621 – Ext. 4
Switching from incandescent lighting to LED lighting with dimming can save you anywhere from 85 to 95% of your lighting electricity costs. Switching from compact fluorescent lamps (CFLs) to ONCE® LED lighting products saves from 45 to 50%.
Durable and Lasting Product Design
ONCE® animal-centric lighting systems go beyond traditional LEDs by offering a SOLUTION so both the animal and your bottom line benefit. By researching the science of light exclusively for the agricultural market, ONCE® is able to incorporate a robust design that is made specifically for harsh agricultural environments.
The Jelly Jar (JJ), Junction Box (JB), and Hard Wire (HW) versions are suitable for use in wet locations and are IP-66 rated. Article 547 of the National Electric Code requires LED luminaries in agricultural building be suitable for wet locations. This is to prevent electrical shock hazard, reduce the risk of fire, and prolong the life of the equipment.
In addition to being wet-rated, ONCE® lighting systems are built to withstand the corrosive vapors from animal excrement and excessive dust accumulation. This prolongs the life and eliminates maintenance costs.