|Purswell, Joseph - Jody|
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2015
Publication Date: 7/24/2015
Citation: Olanrewaju, H.A., Purswell, J.L., Collier, S.D., Branton, S.L. 2015. Effects of color temperatures (Kelvin) of LED bulbs on blood physiological variables of broilers grown to heavy weights. Poultry Science. 94:1721-1728.
Interpretive Summary: Light management is an important environmental factor that influences growth, reproduction and behavior. Lighting programs have a central purpose of slowing the early growth rate of broilers which allows them to achieve physiological maturity prior to maximal rate of muscle mass accretion. Incandescent lighting has been widely used to light broiler houses, but the disadvantages of short life, high energy consumption, and costly maintenance have become more prominent in poultry production. Over the last three decades, different types of lighting have been invented including light emitting diodes (LED). New regulations are prohibiting the incandescent bulb all over the world and will be replaced by modern lighting based on their positive effects on growth. There are conflicting reports of LED light bulbs impact on bird's performance, which may be due to the specific bulbs and their quality from difference manufacturers. To address this we evaluated the effects of color temperatures (Kelvin) of LED bulbs on blood physiological variables of broilers grown to heavy weights. Four treatments consisted of 3 LED light bulbs (2700k Warm-LED-1, 5000k Cool-LED-1, 5000k Cool-LED-2) and incandescent light (2010k ICD, standard) from d 0 to 56 d of age. The results indicated that the treatments had effects on some of blood physiological variables, but all these variables and acid-base changes were still within the normal acid-base homeostasis and physiological ranges. In addition, blood glucose and plasma corticosterone concentrations were not affected by treatments, indicating that these LED light source did not pose as stressors to modern heavy broiler chickens. This study shows that the 3 LED light bulbs evaluated in this study could be better alternative light sources for commercial poultry facilities that are using ICD bulbs to reduce energy cost and optimize production efficiency without inducing physiological stress on broilers grown to heavy weights.
Technical Abstract: Light-emitting diode (LED) lighting is being used in the poultry industry to reduce energy usage in broiler production facilities. However, limited data are available comparing efficacy of different spectral distribution of LED bulbs on blood physiological variables of broilers grown to heavy weights (> 3.2 kg). The present study evaluated the effects of color temperature (Kelvin) of LED bulbs on blood physiological variables of broilers grown to heavy weights. The experiment was a randomized complete block design. Four light treatments consisted of 3 LED light bulbs (2700k, [Warm-LED]; 5000k, [Cool-LED-#1]; 5000k, [Cool-LED-#2]) and incandescent light (ICD, standard) from 0 to 56 d of age. A total of 960 1-d-old Ross × Ross 708 chicks (30 males/30 females/room) were equally and randomly distributed among 16 environmentally-controlled rooms at 50% RH. Thus, each of the four treatments was represented by four rooms. Feed and water were provided ad libitum. All treatment groups were provided the same diet. Venous blood samples were collected on d 21, 28, 42, and d 56 of age. Treatments had significant (P = 0.05) effects on BW, pH, pCO2, pO2, sO2, and K+. However, all these acid-base changes remained within the normal acid-base homeostasis and physiological ranges. In addition, no effect of treatments was observed on HCO3-, Hct, Hb, Na+, Ca2+, Cl-, McHc, mOsm, and anion gap. Moreover, blood glucose and plasma corticosterone concentrations were not affected by treatments, indicating that the treatments did not induce physiological stress in broilers. This study shows that the 3 LED light bulbs evaluated in this study may be suitable for replacement of ICD light sources in commercial poultry facilities to reduce energy cost and optimize production efficiency without inducing physiological stress on broilers grown to heavy weights.