Solid sidewall poultry housing has created a situation where lighting is now a major cost center. Loss of natural daylight means any light birds receive is now provided artificially with bulbs, which have an energy cost associated with them. Currently, incandescent, fluorescent, high pressure sodium, cold cathode and other lighting options are available to poultry producers, but choosing the correct one can be difficult. Since April 2006, the Applied Broiler Research Farm (ABRF) at the University of Arkansas has evaluated the energy usage associated with different light sources.
Energy Use and Cost
The ABRF sub-meters electricity used for lighting through a separate electric meter that allows accurate measurement of lighting kilowatt hour electricity usage.
After farm renovations were completed in April 2006, all four houses had two rows of 60-watt incandescent lights above the feed lines and a center row of brood lights that was 75-watt incandescent. Houses one and two have a total of 75 bulbs (42 dimmable lights plus 33 brood lights) while houses three and four have a total of 90 bulbs (50 dimmable lights plus 40 brood lights).
Prior to the start of the December 2006 flock, the 60-watt incandescent dimmable lights in house three were replaced with 8-watt dimmable cold cathode bulbs with a 2,700 Kelvin rating. Incandescent brood lights were not changed. Kilowatt hour usage for lighting during the December 2006 flock was 1,790 hrs., 1,740 hrs., 705 hrs., and 2,054 hrs. for houses one through four, respectively.
See 'Poultry House Lighting Electrical Usage and Cost' figure at right to see the energy cost associated with the Dec. 2006 usage. There was no difference in average weights, feed conversion or mortality for each of the houses.
A second flock was placed and bird weights (as measured by in-house bird scales) in the 2,700 Kelvin light house began to decline once the brood lights were turned off. The brood lights were turned back on until birds were five weeks old to help stimulate growth and this resulted in less electricity savings difference.
It was determined that the current strain of birds were more sensitive to light intensity and the 2,700 Kelvin cold cathode only provided 0.35 to 0.50 ft-candles at the feed line compared to 0.5 ft-candles in the incandescent houses. In addition, the 2,700 Kelvin cold cathode bulb gave off an orange tint similar to a 60- or 75-watt incandescent bulb.
Using Cold-Cathode Lighting
To help address these concerns, we began working with an Arkansas lighting vendor (Precision Lighting Systems, Inc.; Hot Springs, Ark.). Prior to the May 2007 flock, the incandescent dimmable lights in house four were replaced with 8-watt cold cathode bulbs with a 4,000 Kelvin rating. These bulbs have a slight bluish tint compared to the orange tint of the 2,700 Kelvin bulb; and, are able to deliver 0.50 ft.-candles of light at the feed line.
Therefore, the May 2007 flock consisted of all incandescent bulbs in houses one and two, incandescent brood lights and 2,700 Kelvin 8-watt cold cathode dimmable lights in house three, and incandescent brood lights and 4,000 Kelvin 8-watt cold cathode dimmable lights in house four.
(Compare the lighting and electricity use of the 2007 flocks as well, in the figure at left.)
Switching to energy efficient bulbs has dramatically cut energy usage and costs associated with lighting at the ABRF. Immediately after farm renovation (April through November 2006) when all 4 houses were using 60- and 75-watt incandescent bulbs, kilowatt hour usage for lights on the farm averaged 9,432 hrs. at a cost of $660 per flock over a 4-flock period. From February through August 2008, with houses one and two using 23-watt dimmable fluorescent bulbs and houses three and four using a combination of 15- and 30-watt fluorescent brood lights and 8-watt cold cathode grow lights, kilowatt hour usage on the farm for lights averaged 1,996 hours at a cost of $140 for a 3-flock period.
Thus, savings after switching to energy efficient lighting have averaged 7,436 kilowatt hrs. and $520 per flock at the ABRF. Bulb failures have been somewhat less on the cold cathode vs. the 23-watt dimmable fluorescent; averaging approximately one to two bulbs every other flock for the cold cathode and two to three per flock on the dimmable fluorescent.
Energy Efficient Solutions
There are a number of energy efficient alternatives to incandescent lighting now available although all are more expensive initially. The cold cathode bulbs we are currently using sell for about $9 per bulb but cheaper options are available when bulk purchasing the bulbs. However, life expectancy of the cold cathodes is approximately 25,000 hrs. as compared to an incandescent bulb which has an estimated life span of approximately 2,000-5,000 hrs. depending on the quality of the bulbs. So think long-term savings, not simply initial up-front bulb cost.
Producers should give serious consideration to lighting alternatives that conserve energy and offer long-term savings.
G.T. Tabler, S.E. Watkins and P.A. Watkins are with the University of Arkansas Division of Agriculture and AEP Southwestern Electric Power Company.
