Etlik Piliçlerde Aralıklı Aydınlatma ve Işık Spektrumunun Tibiotarsal Morfometri ve Biyomekanik Üzerine Etkileri

Abstract

Aydınlatma rejimi, etlik piliç yetiştiriciliğinde iskelet gelişimi ve hayvan refahı açısından kritik bir çevresel faktördür. Bu çalışmada fotoperiyot deseninin (kesintisiz vs. aralıklı) ve ışık spektrumunun (beyaz vs. yeşil) tibiotarsus’un morfometrik ve biyomekanik özellikleri üzerindeki birleşik etkileri değerlendirildi. Kırk dört etlik piliç rastgele olarak dört gruba ayrıldı ve 42 günlük yaşa kadar ilgili ışık koşullarına maruz bırakıldı. Morfometrik parametreler—kemik uzunluğu, dış ve iç çaplar ile kortikal indeksler—dijital kumpas kullanılarak ölçüldü. Biyomekanik özellikler, kırılma yükü, rijitlik, atalet momenti ve elastik modülün belirlenmesi amacıyla üç nokta eğme testi ile değerlendirildi. Aralıklı aydınlatma, kesintisiz aydınlatmaya kıyasla kemik uzunluğu ve craniocaudal iç çapta anlamlı artış sağlamıştır (P < 0,05). Bu durumun, artan lokomotor aktiviteye bağlı mekanik yüklenmenin sonucu olduğu düşünülmektedir. Kırılma yükü ve rijitlik gibi mekanik parametreler aralıklı aydınlatmada artış eğilimi göstermiştir (+%3,9 ve +%4,3); ancak bu farklar istatistiksel olarak anlamlı bulunmamıştır. Beyaz ve yeşil ışık arasında ise ne morfometrik ne de biyomekanik açıdan anlamlı bir fark gözlenmemiştir. Sonuç olarak, aralıklı aydınlatmanın, mekanik dayanımda belirgin bir değişiklik olmasa bile, kemik morfometrik özelliklerini iyileştirerek etlik piliçlerde iskelet gelişimine katkı sağlayabileceği belirlenmiştir. Işık spektrumunun etkisinin sınırlı kalması, kontrollü koşullarda bacak sağlığı ve refahını geliştirmede fotoperiyot manipülasyonunun spektral düzenlemeye kıyasla daha etkili bir strateji olabileceğini göstermektedir.

Keywords

• biyomekanik
• etlik piliç
• fotoperiyot
• ışık spektrumu
• kanatlı refahı
• tibiotarsus

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

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

References

1. Abo Ghanima MM, Abd El-Hack ME, Abougabal MS, Taha AE, Tufarelli V, Laudadio V, Naiel MAE, 2021: Growth, carcass traits, immunity and oxidative status of broilers exposed to continuous or intermittent lighting programs. Animal bioscience, 34(7), 1243–1252. https://doi.org/10.5713/ajas.20.0328
2. Ashabranner GG, Czarick III M, Fairchild BD, 2025: Evaluating the Effect of Daylength (24, 20, and 18 hours) during Brooding on Broiler Performance and Physiological Responses to Light Environment. J Appl Poult Res, 100558. https://doi.org/10.1016/j.japr.2025.100558
3. ASABE Standards 2007 [ANSI/ASAE S459 MAR1992 (R2007)].
4. Brickett KE, Dahiya JP, Classen HL, Annett CB, Gomis S, 2007: The impact of nutrient density, feed form, and photoperiod on the walking ability and skeletal quality of broiler chickens. Poult Sci, 86(10), 2117-2125. https://doi.org/10.1093/ps/86.10.2117
5. Cao J, Wang Z, Dong Y, Zhang Z, Li J, Li F, Chen Y, 2012: Effect of combinations of monochromatic lights on growth and productive performance of broilers. Poult Sci, 91(12), 3013-3018. https://doi.org/10.3382/ps.2012-02413
6. Classen HL, Riddell C, Robinson FE, 1991: Effects of increasing photoperiod length on performance and health of broiler chickens. Br Poult Sci, 32(1), 21-29. https://doi.org/10.1080/00071669108417324
7. Deep A, Schwean-Lardner K, Crowe TG, Fancher BI, Classen HL, 2010: Effect of light intensity on broiler production, processing characteristics, and welfare. Poult Sci, 89(11), 2326-2333. https://doi.org/10.3382/ps.2010-00964
8. Halevy O, Biran I, Rozenboim I, 1998: Various light source treatments affect body and skeletal muscle growth by affecting skeletal muscle satellite cell proliferation in broilers. Comp Biochem Physiol A Mol Integr Physiol, 120(2), 317-323. https://doi.org/10.1016/s1095-6433(98)10032-6

9. Harash G, Richardson KC, Alshamy Z, Hünigen H, Hafez HM, Plendl J, Al Masri S, 2020: Basic morphometry, microcomputed tomography and mechanical evaluation of the tibiotarsal bone of a dual-purpose and a broiler chicken line. PLoS One, 15(3), e0230070. https://doi:10.1371/journal.pone.0230070
10. Kang SW, Christensen KD, Kidd Jr MT, Orlowski, SK, Clark J, 2023: Effects of a variable light intensity lighting program on the welfare and performance of commercial broiler chickens. Frontiers in Physiology, 14, 1059055. https://doi.org/10.3389/fphys.2023.1059055 Khan K, Kilimci FS, Kara ME, 2021: Biomechanical tests: Applications and their reliability for the prediction of bone strength in broiler chicken. MAE Vet Fak Derg, 6(2), 85-92. https://doi.org/10.24880/maeuvfd.936262
11. Lilburn MS, 1994: Skeletal growth of commercial poultry species. Poult Sci, 73(6), 897-903. https://doi.org/10.3382/ps.0730897
12. Lynch M, Thorp BH, Whitehead CC, 1992: Avian tibial dyschondroplasia as a cause of bone deformity. Av Pathol, 21(2), 275-285. https://doi.org/10.1080/03079459208418842
13. Nasirzadeh N, Zamiri M J, Akhlaghi A, Ghovvati S, Kargar S, Amini J, 2025: Influence of LED light spectra and photoperiods on performance, bone characteristics and related genes expression in broiler breeders. Br Poult Sci, 66(3), 315-323. https://doi.org/10.1080/00071668.2024.2425627
14. Prayitno DS, Phillips CJ, Omed H, 1997: The effects of color of lighting on the behavior and production of meat chickens. Poult Sci, 76(3), 452-457. https://doi.org/10.1093/ps/76.3.452
15. Prescott NB, Wathes CM, Jarvis JR, 2003: Light, vision and the welfare of poultry. Anim Welf, 12(2), 269-288. https://doi.org/10.1017/S0962728600025689
16. Perretti A, Oyeniran, VJ, Cherry JM , Whittle RH , Grider Z, Nelson AH , Kang, SW , Erf GF, Weimer SL , 2025: Effects of Light Wavelength on Broiler Performance, Blood Cell Profiles, Stress Levels, and Tibiotarsi Morphology. Animals, 15(16), p.2372. https://doi.org/10.3390/ani15162372
17. Rozenboim I, Biran I, Chaiseha Y, Yahav S, Rosenstrauch A, Sklan D, Halevy O, 2004: The effect of a green and blue monochromatic light combination on broiler growth and development. Poult Sci, 83(5), 842-845. https://doi.org/10.1093/ps/83.5.842
18. Rozenboim I, Biran I, Uni ZE, Robinzon B, Halevy O, 1999: The effect of monochromatic light on broiler growth and development. Poult Sci, 78(1), 135-138. https://doi.org/10.1093/ps/78.1.135
19. Sakata AJ, Siqueira JAC, 2024: Lighting in broiler poultry houses: optimization for growth, welfare and sustainability. Revista Caribeña de Ciencias Sociales, 13(12), e4377-e4377.
20. Schwean-Lardner K, Fancher BI, Classen HL, 2012: Impact of daylength on behavioural output in commercial broilers. Appl Anim Behav Sci, 137(1-2), 43-52. https://doi.org/10.1016/j.applanim.2012.01.015
21. Turner CH, 2002: Bone biomechanics handbook (2nd ed.). CRC Press. Van Der Klein SAS, Berghof TVL, Arts JAJ, Parmentier HK, Van Der Poel JJ, Bovenhuis AH, 2015: Genetic relations between natural antibodies binding keyhole limpet hemocyanin and production traits in a purebred layer chicken line. Poult Sci, 94(5), 875-882. https://doi.org/10.3382/ps/pev052
22. Wang QB, Li CM, Jiang RS, Li SF, Huang HY, Huang ZY, Wang ZC, Zhao ZH, 2022: Effects of different intermittent illumination patterns on production performance of slow growing type Yellow chickens. European Poultry Science, 86, 1-14. https://doi.org/10.1399/eps.2022.351
23. Zampiga M, Calini F, Sirri F, 2021: Importance of feed efficiency for sustainable intensification of chicken meat production: implications and role for amino acids, feed enzymes and organic trace minerals. World's Poultry Science Journal, 77(3), 639-659. https://doi.org/10.1080/00439339.2021.1959277
24. Zawilska JB, Berezińska M, Rosiak J, Vivien-Roels B, Skene DJ, Pévet P, Nowak JZ, 2003: Daily variation in the concentration of melatonin and 5-methoxytryptophol in the goose pineal gland, retina, and plasma. Gen Comp Endocrinol, 134(3), 296-302. https://doi.org/10.1016/s0016-6480(03)00269-7