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Shine a little light

Lighting is a major cost factor in broiler production. Traditionally, incandescent bulbs have been used for this purpose. But much more energy efficient sources are available nowadays. The Light Emitting Diode (LED) seems to be the light source of the future. US field tests have proved its savings and advantages.

By Dr. Susan Watkins and Susan Sullivan , Center of Excellence for Poultry Science, University of Arkansas Division of Agriculture and Cooperative Extension Service
Utilisation of solid side wall barns in the broiler industry provides a more uniform environment for rearing broilers, but does increase electrical costs associated with lighting as compared to traditional open sided barns. An energy audit in 2006 conducted by Phil Watkins, (American Electric Power, AEP) of the renovated Applied Broiler Research Farm (ABRF) of the University of Arkansas, indicated that replacing 40 bulbs that were 60 watt incandescent bulbs with energy efficient lighting such as 8 watt cold cathodes or 15 watt compact fluorescent bulbs, resulted in a 66% saving in lighting energy usage in a six week growing period and 75% lighting energy saving for an eight week grow-out when 52 of the 60 watt incandescent bulbs were replaced.
Many poultry producers have installed these more efficient technologies and while the savings are real, the frustrations associated with using these lamps include short life span of bulbs (sometimes barely lasting a flock) and significant loss of light output due to lamp lumen depreciation and dust accumulation particularly on the spiral compact fluorescent tube.
LED good alternative
Light emitting diodes or LED bulbs are not a new technology, but their use in poultry barns in the US has been limited until 2-3 years ago. Hailed as the light of the future for its energy efficiency and durability, they are steadily becoming the norm for lighting in schools, parking lots and other commercial settings, yet little data are available to determine if this more efficient yet expensive light has a place in poultry production barns.
Funding provided through the American Reinvestment and Recovery Act was used for a demonstration of LED lighting on broiler farms in Arkansas. All lights demonstrated were first evaluated in one of the four solid side wall broiler houses at the ABRF unit where each house has three electrical meters: one for lights, one for fans and feed augers and a third meter measuring total electrical usage. Three different LED lamps were evaluated and energy savings was found to be 80% or more compared to incandescent bulbs and bird performance was not compromised.
On farm test
In the field demonstration, three LED bulbs, 10 watt, 3700 Kelvin, 400 lumen Next Gen Illumination bulbs (NG); 10 watt, 6000 Kelvin, 400 lumen Power Secure bulbs (PS); and 6.7 watt, 6000 Kelvin, 600 lumen Luma Vue (LV) bulbs were compared to the energy efficient lighting technology currently used by the industry which included 2700 Kelvin and 4100 Kelvin 8 watt, 325 lumen cold cathodes (2700KCC and 4100KCC, respectively), and 15 watt, 1100 lumen dimmable compact fluorescent lamps (DCFL). The target was to install each technology on three farms. All farms were also given the option to install 23 or 26 watt non-dimmable compact fluorescent lamps (CFL) for brood lights.
The higher wattage and higher lumen CFL was used in the high ceiling houses with the lower wattage targeted towards the drop ceiling houses. Two of the farms kept their existing brood lights of 150 watt sodiums or tube fluorescents. The majority of the participants were using 100 watt incandescent bulbs for brooding and 60 watt incandescent bulbs for grow lights which were dimmed on schedules provided by their integrators.
Different weights
The 19 demonstration farms were selected by the 16 participating broiler complexes and represented different bird slaughter weights ranging from 3.6 to 9.5 pounds and grow-out cycles ranging from 37 to 66 days. Eight farms grow 5 to 6.5 pound average bird weights with 44-58 day grow-out cycles, seven farms grow 6 to 9.5 pound average bird weights with grow-out cycles of 47-64 days and the remaining two farms grow 3.6 to 4.55 pound average bird weights with 37-43 day grow-out cycles.
The majority of participants were four house farms with one- three house farm; two- two house farms, one ten house farm and one six house farm. On the ten house farm, the NextGen Illumination LED was installed as grow bulbs in five houses (50 bulbs/house) and 23 watt CF for brood light (38/house) and the remaining five houses kept their existing 60 watt incandescent bulbs for grow lights and 100 watt incandescent bulbs for brooding.
On the six house farm, the Power Secure bulbs were installed in four houses (42/house) and 23 watt CF for brood light (20/house) and the remaining two houses kept their 60 watt incandescent bulbs for grow lighting and 100 watt incandescent bulbs for brood lighting.
Brood and grow lights
The majority of the houses in the demonstration had grow lights on 20 foot centres over the feed lines with brood bulbs located every 10 feet between the grow lights on the brood end of the house. A few houses had brood lights only in the centre of the house located on 20 foot centres. Participant farms shared two year production and energy usage data from prior to the installation of the new bulbs and have provided this data post installation for approximately 11-13 months for an average of six flocks with the longer grow-out cycles averaging four flocks to date.
In addition, light intensity measurements at floor level was measured in a grid pattern every 10 feet down the length of the barn to the half house with eight readings taken across the barn at each 10 feet, from the sidewall to the outside drinker to the feed line then on the inside of the inside drinker line and then repeated on the opposite side. The readings were averaged to give an average foot candle of light for the barn. This was done for the existing bulbs then again after the new bulbs were installed and then after each flock was removed. This was done with brood and grow lights on which would represent brood light intensity and then brood lights were shut off and grow light intensity without dimming measured.

Dramatic improvements
The most significant finding was how little brood light growers had prior to installation of the new brood and grow bulbs. The average FC of brood light across all farms with the exception of the houses with the fluorescent tubes or high pressure sodium bulbs for brooding was less than two foot candles.
All farms which received the new 23 or 26 watt CFL experienced dramatic improvements in average brood light foot candles with the most significant improvement in light output being in the houses which combined the LV bulbs with the 23 or 26 w CFL.
The second most significant finding was the dramatic loss of average light, 50-80%, over time from the CFL lights installed for brooding. This light loss was attributed to dirt accumulation on the spiral bulbs along with lamp lumen loss. The farms with the CFL bulbs combined with the CC2700K , CC4100K and the DCFL began experiencing lighter birds at market age within the last two flocks and most of these farms have removed the bulbs.
The only farm to date which has continued to perform well with the CC2700K is the one which uses the fluorescent tubes for brooding where brooding light loss has been about 2% since initiation of the project. Both of the Cold Cathode technologies with the 325 lumens/bulb resulted in only .50 FC or less average light for grow when first installed and the 20-50% loss in average foot candles over the last year has dropped the foot candles of light to a level that is no longer adequate. The second issue encountered has been the significant loss of DCFL and to a lesser extent, the CC. The DCFL have experienced a failure rate of roughly 21% across all the DCFL farms.
No compromise in quality
LV LED combined with new brood bulbs significantly improved light output initially and over the year the LV LED has only lost 20-28% of its light output and average daily gain on the LV farms is .126 lbs. There have been no LV LED bulbs lost to date. The NG LED has also held light output very well with a 16-28% loss in average foot candles and no loss of bulbs with the exception of bulbs that were removed and physically damaged. Average daily gain for the NG LED is .129 lbs. (Figure 1) which is the highest for all the bulbs evaluated and higher than average daily gain for all participants prior to the retrofit for the two year data provided.
The greatest disappointment has been the PS LED which did well on light output and bird performance until the last two flocks. Within a two month window, all the PS LED bulbs turned a dull dim yellow and light output dropped 60-90%. Oddly it was not a steady loss over time like the DCFL or CCFL but seemed to happen across all farms at roughly the same time. Most of the participants with these bulbs have opted to remove them until the warranty replacements are available.
Discussions with the supplier revealed that they had gone with a chip supplier who sacrificed quality. One of the greatest concerns for the LED technology is compromise in quality to improve cost. Therefore the recommendation of standards such as LM 80 and LM 79 ratings along with UL ratings for ballasted bulbs will be important information for buyers to assure poor quality does not ruin the market.
Enormous energy savings
Regarding energy savings per flock, a difference of 1265 KwH is being consistently found when comparing the NG LED (292 KwH) with the incandescent (1557 KwH) where NG LED replaced 60 watt incandescent bulbs and 23 watt CFL replaced 100 watt incandescent brood lights on the farm rearing birds to 63-65 days. This is an 81% energy savings over incandescent bulbs and when calculated on an average of 10¢/KwH, savings is $126 per house/flock.
Another significant finding on the NG LED metered farm was the operation experienced a lightning strike which knocked out the electrical meters as well as several thousand dollars of equipment. Not a single NG LED was lost. Since this bulb operates on AC, the electrical surge was able to pass through the bulb without damaging it. A similar lightening strike occurred on one of the CC2700K farms. Fifteen bulbs were lost in one house. A second CC2700K producer was preparing his house for placement during severe cold weather. When he went to turn on the lights, he lost 36 bulbs. These stories further emphasise how fragile the cheaper technologies are and how much more durable a well designed LED bulb can be.
Educate producers and suppliers
Finally, Figure 2 summarises energy usage of the different lighting technologies as measured on the ABRF unit in the past few years with the Once Innovation 15 watt LED being installed four flocks ago. These bulbs are also proving to be a good LED option. Producers can save a significant amount of energy converting from incandescent to other energy efficient technologies. However, the field demonstration has shown that not all technologies actually save money. When cheaper DCFL or CCFL lights lose their light output either to dirt accumulation or lumen loss, bird performance can be sacrificed. It will be important to educate producers and companies on what the pros and cons of lighting options are so that initial costs can be weighed against long term benefits.
Thus, LED is proving to be a viable lighting technology for broiler production. The system has shown to be durable under poultry house conditions and support optimal bird performance. Costs of the technology are comparable and currently some of the more economical LED options are available to producers. Producers and companies need to remember that not all LED bulbs are quality products and not all bulbs are designed for poultry production. Therefore demonstrations such as this are valuable tools for providing producers with sound information for determining if LED lights are a good investment for their operation.


Dr. Susan Watkins and Susan Sullivan


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    Zdenko Grajcar

    This article is full of incorrect information. This is far from scientific research. I advise authors to correct it (publicly).
    1./ Author attributes average daily gain to specific LED light source. This is completely wrong assumption since all houses were equipped with two light sources. CFL and LED; CC and LED or HPS and LED. Therefore, average daily gain should be attributed to combination of light sources, not a single light source. In fact, lighting in brooding period is proving to be important.
    2./ Based on my knowledge about this project, lighting schedules and intensities in different houses were different. Chart with average daily gains has no statistical or practical significance. Ironically, incandescent lamps are the only ones with only statistical significance since there is a significantly more data spanning over few years.
    3./ Ironically, none of the mentioned lamps has been tested to any safety standards (UL or other) with exception of AgriShift lamps by Once.
    4./ Author should be more familiarized with LM 79 and LM 80 standards before recommending them as a measure of �quality�. Fact is that LM80 test has very little meaning for poultry applications.
    5./ Spectral and flux data for the mentioned lamps are incorrect and author was notified about discrepancies several times before publishing this article.
    6./ It is not evident that flux losses can be associated with lamp luminous degradation (bad quality) or can be simply attributed to different rate of dust collection in different environmental conditions.
    7./Only energy efficiency data in this article has any practical significance.
    8./ Stating that "Since this bulb operates on AC, the electrical surge was able to pass through the bulb without damaging it" is laughable and completely misleading. It is theoretically and practically impossible for lighting surge to pass 'through the bulb'. Most probable reason why lamps at that location did not get damaged was due to proper grounding of the building and due to proper electrical wiring. It has nothing to do with the lamps.
    I do applaud Dr. Watkins for a lot of work she did in area of poultry lighting. I really do. Proper lighting in poultry houses can significantly enhance poultry productivity, but providing public with inaccurate information and premature, statistically insignificant productivity statements can be more damaging than helpful to the industry. In general, LED lighting is the future for poultry housing. It is much more energy efficient and it is only light source which can be spectrally modified to adopt to spectral sensitivity of domestic fowl.

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    Dr. Susan Watkins and Susan Sullivan

    This was a field demonstration, not a research project, the last sentence restates the fact.

    1./ Bird performance has not been compromised with use of LED lighting. The article clearly states there are other bulbs used along with the LED bulbs. We did not use cold cathodes and LED in the same house.

    2./ I don't know what "charts" you think we are using? nor did we run any statistical analysis. We simply stated ADG is as good or better with houses equipped with LED lamps, until 1 brand of LED failed. This company told us they used a 'cheaper chip'.

    3./ The AgriShift lamp is not in the field demonstration

    4./ LM 80 and LM 79 refers to lumen depreciation. It is an additional tool for assisting producers in understanding lumen loss from light sources.

    5./ I don't believe spectral and flux data are mentioned in the article.

    6./ That's what we said, poor quality and/or dust accumulation.

    8./ We never said LED lighting 'significantly enhances productivity' we said LED light have not compromised productivity, until lamps began to fail. And, once again, this was a field demonstration not a research project.

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    Zdenko Grajcar

    Response to Dr. Watkins response:

    2./ I did refer to Charts with average daily gains from original study on which this article is based. Also, to determine statistical significance, you do not have to run statistical analysis. Definition of statistically significant if it is unlikely to have occurred by chance.
    3./ I simply stated that none of the lamps had was tested to a safety standard. Ironically, author used pictures of AgriShift lamps which were not part of the study and were only lamps with safety approval.
    4./ Again, author should be more familiarized with LM 79 and LM 80 standards before recommending them as a measure of quality. Only LM80 refers to lumen depreciation. LM79 does not. LM80 is based on human vision and human perception of the light. LM80 test has very little meaning for poultry applications.
    5./ Yes you do mention spectral and flux data. CCT (Correlated Color Temperature) is a spectral measure or in belter words spectral characteristic of visible light. And Lumen is SI unit of luminous flux.
    8./ Heading of paragraph 5 is 'DRAMATIC IMPROVEMENTS'. In my interpretation and most likely in interpretation of many other readers, 'dramatic improvement' is equal and synonymous with 'significantly enhanced'.

    I do agree that this was field demonstration. However, it was and it still is presented as a field research study.

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