Interactive effects of light sources, photoperiod, and strains on growth performance, carcass characteristics and health indices of broilers grown to heavy weights

Authors: Olanrewaju, Hammed; MILLER, W - Advanced Animal Eye Care; MASLIN, W - Mississippi State University; Collier, Stephanie; Purswell, Joseph - Jody; Branton, Scott

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2019
Publication Date: 11/22/2019
Publication URL: https://handle.nal.usda.gov/10113/6829284
Citation: Olanrewaju, H.A., Miller, W.W., Maslin, W.R., Collier, S.D., Purswell, J.L., Branton, S.L. 2019. Interactive effects of light sources, photoperiod, and strains on growth performance, carcass characteristics and health indices of broilers grown to heavy weights. Poultry Science. 98(12):6232-6240. https://doi.org/10.3382/ps/pez476.
DOI: https://doi.org/10.3382/ps/pez476

Interpretive Summary: Most governments around the world including the USA have passed measures to phase out incandescent (ICD) bulbs due to its inefficiency in favor of more energy-efficient lighting alternatives, including cold cathode fluorescent lamps (CCFL), compact fluorescent lamps (CFL), and light emitting diodes (LED) among others. Although, most of the research involving light management has focused on light sources, photoperiods, or each in combination with other factors. The rate of development differs among genetic strains and lighting program needs may be genetic strain specific for these two strains in order to optimize growth performance, but substantial reliable scientific information is limited for these two strains. Information is sparse on the effect of differing photoperiods with the new light sources currently used by the poultry industry in combination with genetic strains on broiler growth performance and welfare indices since establishing proper welfare practices are central to international trade negotiations of meat products. Therefore, the objective of this study was to evaluate the effects of light sources (CFL, LED, PS-LED) bulbs in comparison with incandescent (ICD) bulbs, photoperiod in combination with these two genetic strains on growth performance, carcass characteristics, and health indices of broilers grown to heavy weights (> 3.0 kg). In each trial of the 2 trials, we evaluated the effects of light sources, photoperiods, and genetic strains on growth performance, carcass characteristics, and health indices of broilers grown to heavy weights. The results indicated that the BW, BW gain, live weight, and carcass weights of birds reared under Cool-PS-LED were different in comparison to birds reared under ICD, but feed intake, feed to gain ratio, and mortality were not affected. Moreover, broilers subjected to short/non-intermittent photoperiod had lowest body weight, body weight gain, feed intake, carcass weight, and pectoralis major and minor weights compared with regular/intermittent photoperiods. There was no effect of treatments on most carcass characteristics. There was no effect of treatments on welfare indices, suggesting that the light sources evaluated did not compromise welfare of broilers grown to heavy weights. It was concluded that the use of these 3 evaluated light sources, especially Cool-PS-LED along with regular/intermittent photoperiod in commercial poultry facilities would reduce energy costs and optimizing production efficiency without compromising the welfare of broilers grown to heavy weights.

Technical Abstract: Effects of light sources, photoperiods, and genetic strains on growth performance, carcass characteristics, and health indices of broilers grown to heavy weights (>3 kg) were evaluated. The experimental design was a 4 × 2 × 2 factorial treatments consisting of 4 light sources [incandescent (ICD, standard), compact fluorescent (CFL), neutral light emitting diode (Neutral-LED), and cool poultry specific LED (Cool-PS-LED)], 2 photoperiods (regular/intermittent [2L:2D], and short [8L:16D], and 2 genetic strains (Strain A, Strain B). In each trial, chicks of two different strains from different commercial hatcheries were equally and randomly distributed into 16 environmentally-controlled rooms at 1 d of age. Each room was randomly assigned one of sixteen treatments from d 1 to 56 d of age. Feed and water were provided ad libitum. Birds were provided a four phase-feeding program (starter, grower, finisher, withdrawal). Birds and feed were weighed on 1, 14, 28, 42, and 56 d of age for growth performance. On d 56, 20 (10 males and 10 females) birds from each room were processed to determine weights and yields. The BW, BW gain, live weight and carcass weight of birds reared under PS-LED were higher (P = 0.05) in comparison with birds reared under ICD, but FI, FCR, mortality, and carcass characteristics were not affected by treatments. Also, broilers subjected to the short/non-intermittent photoperiod had the lowest (P = 0.05) growth performance and carcass characteristics compared with values obtained for regular/intermittent photoperiods. In addition, genetic strain was significant (P = 0.05) for most of the examined variables. Feed conversion, fat, tender, and yield were not affected by treatments. There was no effect of photoperiod, light sources, or their interactions on mortality. This study shows positive impacts on alternative light sources when compared to ICD along with regular/intermittent photoperiod in commercial poultry facilities, thereby reducing energy costs and optimizing production efficiency without compromising the welfare of broilers grown to heavy weights.