Effects of Intermittent Lighting and Light Spectrum on Tibiotarsus Morphometry and Biomechanics in Broilers

Authors : İsmail Gökçe Yıldırım, Firuze Türker Yavaş, Figen Sevil Kilimci

Pages : 143-149

Doi:10.31196/huvfd.1781934

View : 49 | Download : 117

Publication Date : 2025-12-24

Article Type : Research Paper

Abstract :The lighting regime is a critical environmental variable in broiler production, with significant implications for skeletal development and welfare. This study evaluated the combined effects of photoperiod pattern (continuous vs. intermittent) and light spectrum (white vs. green) on the morphometric and biomechanical characteristics of the tibiotarsus in broiler chickens. Forty-four broilers were randomly assigned to four groups and exposed to the respective light conditions until 42 days of age. Morphometric parameters, including bone length, external and internal diameters, and cortical indices, were measured using digital calipers. Biomechanical properties were assessed via three-point bending tests to determine fracture load, stiffness, moment of inertia, and elastic modulus. Intermittent lighting significantly increased bone length and internal craniocaudal diameter compared to continuous lighting (P < 0.05), likely reflecting increased mechanical loading from enhanced locomotor activity. Although mechanical parameters such as fracture load and stiffness exhibited positive trends under intermittent lighting (+3.9% and +4.3%, respectively), these differences did not reach statistical significance. No significant differences were observed between white and green light in either morphometric or biomechanical outcomes, suggesting limited spectral influence under the conditions tested. In conclusion, the findings indicate that intermittent lighting may improve skeletal development in broilers by enhancing morphometric bone traits, even in the absence of marked changes in mechanical strength. The negligible effect of light spectrum suggests that, under controlled conditions, photoperiod manipulation may be a more effective strategy than spectral adjustment for promoting leg health and welfare in commercial broiler production.
Keywords : biomechanics, broiler, light spectrum, photoperiod, poultry welfare, tibiotarsus

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