Broilers Surface Temperature Under the Use of Led Lighting Rodrigo G. Garcia¹ , Mayara R. Santana¹, Irenilza A. Nääs¹, Rodrigo Borille¹, Ana F. B. Royer¹, Ibiara C. L. Almeida Paz¹, Fabiana R. Caldara¹, Nilsa D. S. Lima¹, Kelly C. Nunes¹, Sandro Colet¹ ¹Federal University of Grande Dourados, UFGD, Brazil E-mail: rodrigogarcia@ufgd.edu.br Abstract: The standard incandescent light bulb used in broiler production generally produces insufficient light and sensible heat, which may affect the birds’ thermal environment and welfare. The LED light source presents a high luminous efficiency, besides leading to less heat output, and it reduces the cost with energy during broiler production. The aim of this study was to evaluate the surface temperature of broiler chickens reared under different LED bulb colors, compared to the fluorescent light bulb source, at different ages. We used 1350 male Cobb® pullets in this trial. At the 10th day of growth, the birds were reared under five light treatments: T1 through T4, using 4 LED colors (yellow, red, blue, white), and T5, using compact fluorescent bulbs, with light intensity of 20 lx. The birds were distributed in a fully randomized design within the five treatments with five replicates with 54 birds in each. The broilers’ surface temperature was recorded at 21, 28, 35 and 42 days of growth, at 7 PM, using an infrared thermography camera. Analysis of variance was applied to the results. No difference was found in the broilers’ surface temperature reared under the different LED bulb colors (p > 0.05). There was a difference in the surface temperature (p  0.05) related to the age of the birds which were 32.36 °C at 21 days, 29.58 °C at 28 days, 26.31 °C at 35 days, and 23.89 °C at 42 days of growth. The decrease in surface temperature is due to the use of fans to cool down the ambient temperature as the broiler’ grow out period ends at 42 days. Keywords: broiler welfare, lighting emitting diode, rearing environment Introduction The evolution in broiler production suggests great advancements towards animal welfare and an overall improvement in production aspects. The success of broiler production is related to several factors amongst them there are those related to the birds’ biological functions. Ambient lighting was initially recognized as an important variable in 1944 (Gabriel, 2003). The use of artificial lighting in broiler production allows better feed ration and water ingestion, growth, behavior and adaptation during the grow out period, than using only natural lighting (Mendes et al., 2010). For several years incandescent lights were used generating low iluminance and some amount of heat with prejudice to the performance and welfare of broilers (Pereira et al., 2012). Recently LED light started to be significant in the search for a good and economic source of light as it represents high iluminance efficiency with low heat production, besides being less expensive than other light sources found in the market. This research aimed to evaluate the surface temperature of broilers at various ages, reared in an environment with LED light in various colors, compared to those reared under fluorescent light. Material and Methods