Yeter The J. Anim. Plant Sci. 31(1):2021 26 POINT LED LIGHT SOURCES ATTACHED ON THE FEEDERS AND DRINKERS, AS AN ILLUMINATION SYSTEM IN BROILER HOUSES: EFFECTS ON BROILER PERFORMANCE B. Yeter Department of Animal Science, Faculty of Agriculture, University of Kahramanmaras Sutcu Imam, Kahramanmaras, Turkey Corresponding author’s email: byeter@gmail.com ABSTRACT The experiment was carried out to evaluate effects of point Light Emitting Diode (LED) lights source attached to the feeders and drinkers on the broiler performance compared with the standard ceiling with the bulb in environment controlled house with two clusters. Total of 3360 chicks were divided into 2 groups (control and experimental) consisting 3 replicates of 560 chicks with 12.5 birds/m 2 stocking density. Although, light intensity was measured as 18 lux at the level of feeders for the control group, it was measured 82 lux inside the feeders, 12 lux at the outer edge of them, while the measuring was showing 1 lux at 15 cm distance from the feeders 8 lux at the water dropper and zero in other areas for the experimental group. Standard rearing techniques and commercial diets were used during experimental period and parameters such as growth performance, feed conversion ratio (FCR) and mortality of broiler chicks were determined. The mean chick weight at the beginning of the experiment was similar in the control and experimental groups. There was no difference between lighting applications at the age of first week, however, at later stages, body weight (BW) was recorded significantly higher (P≤0.05, P≤0.01) in LED illumination treated group compared to control group. No significant differences were observed in feed intake and FCR between lighting treatments. In 42 day old, feed conversion ratios in control and LED lighting treated group were determined as 1.651 and 1.607, respectively (P>0.05). The mortality rates of control and LED lighting treated groups were found to be 5.24 and 3.51 (P≤0.05) at the age of 42 days. No negative effect of Point LED lights system on weekly body weight gain, feed intake, and feed conversion ratios were observed, but a positive effect on cumulative body weight and mortality. Therefore, pointed LED can be used as a lighting system in broiler production being cost effective without compromising the productive performance. Key words: Broiler, Lighting, Pointed LED, Performance. https://doi.org/10.36899/JAPS.2021.1.0189 Published online August 26, 2020 INTRODUCTION Lighting, an extremely significant environmental and primary microclimate factor in poultry production, plays a pivotal role for the release of various hormones that influence growth, development and physiological functioning (Olanrewaju et al., 2006; Baser and Yetisir, 2010; Ahmad et al., 2011; Yang et al., 2015; Olanrewaju et al., 2016; Zhao et al., 2019). Physiological activities and behavioural processes of birds are externally controlled by lighting programs (Brown, 2010; Mahmood et al., 2014; Pandey, 2019). Therefore, light source, intensity and lighting programs are significant management tools to regulate broiler production and welfare, playing an important role in broiler’s health (Deep et al., 2010; Blatchford et al., 2012; Olanrewaju et al., 2016). In animal husbandry sector and especially in broiler production, research on animal welfare is raising awareness (Raccoursier Frost, 2016). Lighting program is a strategic application used in broiler production aiming at reducing the incidence of metabolic and skeletal disorders in broiler chickens (Olanrewaju et al., 2014 a). Although it is possible to classify lighting programs from different angles, a classification made in the form of continuous, discrete and restricted lighting programs is in practice (Baser and Yetisir, 2010). It has been found that continuous light application, which has been widely used in broiler breeding, creates stress in animals (Rozenboim et al., 2010; Classen et al., 2010). Reduced lighting time and light intensity decreases mortality rates (Classen and Riddell, 1989; Renden et al., 1991; Blair et al., 1993; Sanotra et al., 2002; Olanrewaju et al., 2006). However, some studies show that mortality rates are not affected by lighting treatments (Olanrewaju et al., 2014a; 2014b, 2016; Evrim et al., 2017). Recently, incandescent and fluorescent Light Emitting Diode (LED) lighting have become more preferable instead of conventional light source in broiler production (Archer, 2015), benefits of this replacement include decrease in energy use, increase in bird performance and improvement in bird welfare. (It is also stated that different light sources and intensity have an The Journal of Animal & Plant Sciences, 31(1): 2021, Page: 26-35 ISSN (print): 1018-7081; ISSN (online): 2309-8694