Comparison Effects of Natural and Artificial Lighting on Selected Blood Physiological Variables of Broilers Grown to 56 Days of Age

Light is one of the major enviro-climatic factors in poultry houses that influences physiology and metabolic processes and impact poultry welfare, health, production and behaviors. This study compared the effects of natural and artificial lighting on selected blood physiological variables of broilers grown to 56 days of age. In each of the two trials, a total of 704 (352 males/352 females) 1-d- old Ross x Ross 708 chicks were obtained from a commercial hatchery on day of hatch. The design structure was a randomized complete block design with two treatments and eight replications per trial. Birds were equally and randomly distributed into 16 environmentally controlled rooms in groups of 44 (22 males/22 females) per room. Thus, each of the two treatments were represented by eight rooms with total of sixteen replicates. Temperature and RH on d 1 were maintained at 90 ± 2.1°F and 50 ± 5%, respectively across all treatments rooms. Temperature was decreased by 4 °F per week until it reached 66 °F at 56 d of age. Feed and water were provided ad libitum. Birds were provided a four phase-feeding program (Starter: 0-14 d, Grower: 15-28 d, Finisher: 29-42 d, and Withdrawal: 43-56 d). Blood samples (3 ml) were collected from the brachial wing vein of 3 males and 3 females birds per room on d 28, 42, and 56 which were then analyzed immediately for whole blood physiological variables. Blood plasma samples were analyzed for T3, T4, and corticosterone concentrations. Results showed that artificial light significantly increased sO2 (P < 0.049), SaO2 (P < 0.031), and decreased RHb (P < 0.044) which may be due to slight difference in body weights, but the changes were all within physiological ranges for this species. In addition, blood glucose and plasma corticosterone concentrations were not affected by treatments, signify a similar level of physiological stress between the two light types. In conclusion, physiological variables examined in this study were unaffected by both natural and artificial lighting. However, birds exposed to artificial lighting had slightly increased body weight in comparison with birds reared under natural lighting, which may have a significant impact in commercial poultry production. USDA Agricultural Research Service. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.