Free-Range Rearing as a Welfare-Oriented System: Enhances Growth, Digestibility, and Lipid Traits of Cobb500 Broilers in Tropical Conditions
Abstract
Free-range poultry production has gained increasing attention due to growing consumer demand for systems that promote animal welfare and sustainable meat production. However, information on the suitability of free-range systems for fast-growing broiler strains under tropical conditions remains limited and warrants further investigation. The current study aimed to evaluate the growth performance, behavior, apparent nutrient digestibility, serum lipid profile, and carcass characteristics of broilers reared under the free-range system. A total of 120 Cobb500 broiler chicks (14 days old) were randomly allocated to either a conventional indoor system or a free-range system with outdoor paddock access. Each treatment included 10 replicates of 6 birds reared in 1 × 1 m pens; free-range pens were provided with additional 1 × 6 m outdoor paddocks. Results revealed that free-range birds exhibited higher levels of foraging and locomotion. In contrast, indoor birds spent more time eating and resting throughout their growth period, especially at five weeks of age (p<0.05). No significant difference (p>0.05) was observed between the two treatments regarding growth performance traits. Meanwhile, broilers reared under a free-range system had significantly higher apparent digestibility of dry matter (p=0.017) and ether extract (p=0.043). In addition, free-range birds exhibited significantly lower serum triglycerides (−16.95%; p=0.001), LDL (−17.20%; p=0.002), VLDL (−14.07%; p=0.023), and LDL/HDL ratio (−20.00%; p=0.002) compared to conventionally reared birds. Abdominal fat content was also significantly reduced (−30%; p=0.003) in the free-range group, while other carcass traits remained unaffected (p>0.05). In conclusion, although the rearing system did not influence growth performance, free-range conditions improved behavioral expression, nutrient digestibility, and lipid metabolism by reducing serum lipid levels and carcass fatness.
Full text article
References
Amato, M. G., & Castellini, C. (2022). Adaptability challenges for organic broiler chickens: A commentary. Animals, 12(11), 1354. https://doi.org/10.3390/ani12111354
Anwar, U., Riaz, M., Farooq Khalid, M., Mustafa, R., Farooq, U., Ashraf, M., Munir, H., Auon, M., Hussain, M., Hussain, M., Ayaz Chisti, M. F., Bilal, M. Q., Rehman, A. ur, & Rahman, M. A. ur. (2023). Impact of exogenous xylanase and phytase, individually or in combination, on performance, digesta viscosity, and carcass characteristics in broiler birds fed wheat-based diets. Animals, 13(2), 1–13. https://doi.org/10.3390/ani13020278
AOAC. (2000). Official methods of analysis (17th ed.). Association of Official Analytical Chemists.
Baxter, M., Bailie, C. L., & O’Connell, N. E. (2019). Play behavior, fear responses, and activity levels in commercial broiler chickens provided with preferred environmental enrichments. Animal, 13(1), 171–179. https://doi.org/10.1017/S1751731118001118
Bonnefous, C., Collin, A., Guilloteau, L. A., Germain, K., Ravon, L., Bordeau, T., Chartrin, P., Godet, E., Cailleau-Audouin, E., Couroussé, N., Raynaud, E., Mignon, S. V., Reverchon, M., Mattioli, S., Castellini, C., Angelucci, E., Guesdon, V., Calandreau, L., Berri, C., & Le Bihan-Duval, E. (2024). Performance, meat quality, and blood parameters in four strains of organic broilers differ depending on the range used. Scientific Reports, 14(1), 1–13. https://doi.org/10.1038/s41598-024-81672-9
Campbell, Y. L., Walker, L. L., Bartz, B. M., Eckberg, J. O., & Pullin, A. N. (2025). Outdoor access versus conventional broiler chicken production: Updated review of animal welfare, food safety, and meat quality. Poultry Science, 104(4), 104906. https://doi.org/10.1016/j.psj.2025.104906
Castellini, C., Mugnai, C., Moscati, L., Mattioli, S., Guarino Amato, M., Cartoni Mancinelli, A., & Dal Bosco, A. (2016). Adaptation to organic rearing system of eight different chicken genotypes: Behaviour, welfare and performance. Italian Journal of Animal Science, 15(1), 37–46. https://doi.org/10.1080/1828051X.2015.1131893
de Jong, I. C., Bos, B., van Harn, J., Mostert, P., & te Beest, D. (2022). Differences and variation in welfare performance of broiler flocks in three production systems. Poultry Science, 101(7), 101933. https://doi.org/10.1016/j.psj.2022.101933
Dong, X. Y., Yin, Z. Z., Ma, Y. Z., Cao, H. Y., & Dong, D. J. (2017). Effects of rearing systems on laying performance, egg quality, and serum biochemistry of Xianju chickens in summer. Poultry Science, 96(11), 3896–3900. https://doi.org/10.3382/ps/pex155
Erian, I., & Phillips, C. J. C. (2017). Public understanding and attitudes towards meat chicken production and relations to consumption. Animals, 7(3), 20. https://doi.org/10.3390/ani7030020
Evaris, E. F., Sarmiento-Franco, L., & Sandoval-Castro, C. A. (2021). Meat and bone quality of slow-growing male chickens raised with outdoor access in tropical climate. Journal of Food Composition and Analysis, 98, 103802. https://doi.org/10.1016/j.jfca.2021.103802
Haruna, M. A., Bello, K. O., Adeyemi, A. O., & Odunsi, A. A. (2018). Comparison of conventional and semi-conventional management systems on the performance and carcass yield of broiler chickens. Nigerian Journal of Animal Science, 20(3), 81–87. https://www.ajol.info/index.php/tjas/article/view/166063
Hautefeuille, S., Guillou, S., Bouju-Albert, A., Misery, B., Laroche, B., Haddad, N., & Tareb, R. (2026). Free-range versus conventional: A comparison of microbial composition and Campylobacter contamination in broiler carcasses after chilling. Poultry Science, 105(1), 106111. https://doi.org/10.1016/j.psj.2025.106111
Horna, F., Leandro, G. S., Bícego, K. C., Macari, M., Reis, M. P., Cerrate, S., & Sakomura, N. K. (2023). Energy cost of physical activities in growing broilers. British Poultry Science, 64(4), 483–490. https://doi.org/10.1080/00071668.2023.2191309
Jin, S., Yang, L., Zang, H., Xu, Y., Chen, X., Chen, X., Liu, P., & Geng, Z. (2019). Influence of free-range days on growth performance, carcass traits, meat quality, lymphoid organ indices, and blood biochemistry of Wannan Yellow chickens. Poultry Science, 98(12), 6602–6610. https://doi.org/10.3382/ps/pez504
Kheravii, S. K., Swick, R. A., Choct, M., & Wu, S. B. (2017). Coarse particle inclusion and lignocellulose-rich fiber addition in feed benefit performance and health of broiler chickens. Poultry Science, 96(9), 3272–3281. https://doi.org/10.3382/ps/pex123
Li, Y., Luo, C. L., Wang, J., & Guo, F. Y. (2016). Effects of different raising systems on growth performance, carcass, and meat quality of medium-growing chickens. Journal of Applied Animal Research, 45(1), 326–330. https://doi.org/10.1080/09712119.2016.1190735
Ma, Z., Zhang, J., Ma, H., Dai, B., Zheng, L., Miao, J., & Zhang, Y. (2014). The influence of dietary taurine and reduced housing density on hepatic functions in laying hens. Poultry Science, 93(7), 1724–1736. https://doi.org/10.3382/ps.2013-03654
Marchewka, J., Sztandarski, P., Solka, M., Louton, H., Rath, K., Vogt, L., Rauch, E., Ruijter, D., de Jong, I. C., & Horbańczuk, J. O. (2023). Linking key husbandry factors to the intrinsic quality of broiler meat. Poultry Science, 102(2), 102384. https://doi.org/10.1016/j.psj.2022.102384
Martínez-Pérez, M., Sarmiento-Franco, L. A., Sandoval-Castro, C. A., Santos-Ricalde, R. H., Safwat, A. M., & García-Hernández, Y. (2023). Effect of indoor and free-range raising systems on growth performance of male Rhode Island Red chickens. Tropical and Subtropical Agroecosystems, 26(1), 043. https://doi.org/10.56369/tsaes.4312
Mir, N. A., Rafiq, A., Kumar, F., Singh, V., & Shukla, V. (2017). Determinants of broiler chicken meat quality and factors affecting them: A review. Journal of Food Science and Technology, 54(10), 2997–3009. https://doi.org/10.1007/s13197-017-2789-z
Mulder, M., & Zomer, S. (2017). Dutch consumers’ willingness to pay for broiler welfare. Journal of Applied Animal Welfare Science, 20(2), 137–154. https://doi.org/10.1080/10888705.2017.1281134
Mutibvu, T., Chimonyo, M., & Halimani, T. E. (2019). Effect of strain, sex, and rearing system on carcass and fat yield of Naked Neck, Ovambo, and Potchefstroom Koekoek chickens. Indian Journal of Animal Research, 54(9), 1171–1175. https://doi.org/10.18805/ijar.B-944
Nielsen, S. S., Alvarez, J., Bicout, D. J., Calistri, P., Canali, E., Drewe, J. A., Garin-Bastuji, B., Gonzales Rojas, J. L., Schmidt, C. G., Herskin, M. S., et al. (2023). Welfare of broilers on the farm. EFSA Journal, 21(2), 7788. https://doi.org/10.2903/j.efsa.2023.7788
Papageorgiou, M., Tzamaloukas, O., & Simitzis, P. (2025). Animal welfare protocols and labelling schemes for broilers in Europe. Poultry, 4(3), 1–23. https://doi.org/10.3390/poultry4030029
Pettersson, I. C., Weeks, C. A., Wilson, L. R. M., & Nicol, C. J. (2016). Consumer perceptions of free-range laying hen welfare. British Food Journal, 118(8), 1999–2013. https://doi.org/10.1108/BFJ-02-2016-0065
Połtowicz, K., & Doktor, J. (2011). Effect of free-range raising on performance, carcass attributes, and meat quality of broiler chickens. Animal Science Papers and Reports, 29(2), 139–149.
Ravindran, V., Hew, L. I., Ravindran, G., & Bryden, W. L. (1999). A comparison of ileal digesta and excreta analysis for the determination of amino acid digestibility in food ingredients for poultry. British Poultry Science, 40(2), 266–274. https://doi.org/10.1080/00071669987692
Rehman, M. S., Mahmud, A., Mehmood, S., Pasha, T. N., Hussain, J., & Khan, M. T. (2017). Blood biochemistry and immune response in Aseel chicken under free range, semi-intensive, and confinement rearing systems. Poultry Science, 96(1), 226–233. https://doi.org/10.3382/ps/pew278
Safwat, A. M., Sarmiento-Franco, L. A., Sandoval-Castro, C. A., Santos-Ricalde, R. H., & Ghazalah, A. A. (2026). Assessment of metabolizable energy requirements for broilers in both conventional indoor and free-range rearing systems. Journal of Animal and Feed Sciences, 35(2), 4–10. https://doi.org/10.22358/jafs/211603/2026
Sánchez-Casanova, R. E., Sarmiento-Franco, L., & Phillips, C. J. C. (2022). The effects of providing outdoor access to broilers in the tropics on their behavior and stress responses. Animals, 12(15), 1917. https://doi.org/10.3390/ani12151917
Sánchez-Casanova, R., Sarmiento-Franco, L., Phillips, C. J. C., & Zulkifli, I. (2020). Do free-range systems have the potential to improve broiler welfare in the tropics? World’s Poultry Science Journal, 76(1), 34–48. https://doi.org/10.1080/00439339.2020.1707389
Schreiter, R., Born, T., Herzog, M., & Freick, M. (2025). Free-range rearing characteristics of two German dual-purpose chicken breeds: Dresden chickens and Dresden bantams. Journal of Applied Poultry Research, 34(2), 100530. https://doi.org/10.1016/j.japr.2025.100530
Tellis, C., Sarrigeorgiou, I., Tsinti, G., Patsias, A., Fotou, E., Moulasioti, V., Kyriakou, D., Papadami, M., Moussis, V., Boti, M.-E., Tsiouris, V., Tsikaris, V., Tsoukatos, D., & Lymberi, P. (2024). Pasture vs. coop: Biomarker insights into free-range and conventional broilers. Animals, 14(21), 1–13. https://doi.org/10.3390/ani14213070
Tickle, P. G., Hutchinson, J. R., & Codd, J. R. (2018). Energy allocation and behavior in the growing broiler chicken. Scientific Reports, 8(1), 1–13. https://doi.org/10.1038/s41598-018-22604-2
Tong, H. B., Cai, J., Lu, J., Wang, Q., Shao, D., & Zou, J. M. (2015). Effects of outdoor access days on growth performance, carcass yield, meat quality, and lymphoid organ index of a local chicken breed. Poultry Science, 94(6), 1115–1121. https://doi.org/10.3382/ps/pev032
Van der Eijk, J. A. J., Gunnink, H., Melis, S., van Riel, J. W., & de Jong, I. C. (2022). Reducing stocking density benefits the behavior of both fast- and slower-growing broilers. Applied Animal Behavior Science, 257, 105754. https://doi.org/10.1016/j.applanim.2022.105754
Wang, Y., Ru, Y. J., Liu, G. H., Chang, W. H., Zhang, S., Yan, H. J., Zheng, A. J., Lou, R. Y., Liu, Z. Y., & Cai, H. Y. (2015). Effects of different rearing systems on growth performance, nutrient digestibility, digestive organ weight, carcass traits, and energy utilization in male broiler chickens. Livestock Science, 176, 135–140. https://doi.org/10.1016/j.livsci.2015.03.010
Whittle, R. H., Karcher, D. M., Erasmus, M. A., & Weimer, S. L. (2025). Effects of genetic strain, stocking density, and age on broiler behavior. Poultry Science, 104(2), 104723. https://doi.org/10.1016/j.psj.2024.104723
Zheng, M., Mao, P., Tian, X., & Meng, L. (2021). Effects of grazing mixed-grass pastures on growth performance, immune responses, and intestinal microbiota in free-range Beijing-you chickens. Poultry Science, 100(2), 1049–1058. https://doi.org/10.1016/j.psj.2020.11.005
Authors
Copyright (c) 2026 Tropical Animal Science Journal
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Authors submitting manuscripts should understand and agree that copyright of manuscripts of the article shall be assigned/transferred to Tropical Animal Science Journal. The statement to release the copyright to Tropical Animal Science Journal is stated in Form A. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA) where Authors and Readers can copy and redistribute the material in any medium or format, as well as remix, transform, and build upon the material for any purpose, but they must give appropriate credit (cite to the article or content), provide a link to the license, and indicate if changes were made. If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
Article Details
How to Cite
