Putative Blood Biomarkers on Tropical Resilience in Philippine Native and Crossbred Heifers
Abstract
Hematological values are essential in understanding the health of an animal. Interpretation of these values must consequently be clinically accurate. These values are also putative biomarkers for resiliency under tropical conditions. In this study, blood profiles of Panay Native (PN) and crossbred Holstein x Jersey (HxJ) heifer cattle were compared to identify biomarkers of tropical resilience. Blood samples from 58 heifers were analyzed using General Linear Models and multivariate techniques. Results demonstrated that temperate-derived Reference Intervals frequently misclassified healthy animals. The Panay cattle exhibited a superior erythropoietic phenotype (significantly higher RBC, HGB, PCV, p<0.001), driven by a unique regulatory mechanism in which increased red cell counts were balanced by reduced cell volume (negative RBC-MCV correlation, r = -0.76, p<0.001). In contrast, crossbred heifers exhibited signs of compensated hemolysis, characterized by regenerative anemia (>55% prevalence). Multivariate analysis revealed a clear divergence in physiological strategies, with crossbred cattle displaying a trade-off between erythropoiesis and immune stability, whereas the native cattle demonstrated superior homeostatic stability. Overall, this study confirms that non-localized reference intervals misinterpret the physiological realities of tropical herds, causing systemic diagnostic errors. Furthermore, the unique regulatory patterns substantiate the 'viscosity clamp' or the uncoupling of cell count and volume as putative biomarkers of innate climate resilience in indigenous cattle.
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References
Abramowicz, B., Kurek, Ł., & Lutnicki, K. (2019). Haematology in the early diagnosis of cattle diseases -a review. Veterinarski Arhiv, 89(4), 579–590. https://hrcak.srce.hr/225755
Bagath, M., Krishnan, G., Devaraj, C., Rashamol, V. P., Pragna, P., Lees, A. M., & Sejian, V. (2019). The impact of heat stress on the immune system in dairy cattle: A review. Research in Veterinary Science, 126, 94–102. https://doi.org/10.1016/j.rvsc.2019.08.011
Berghof, T. V. L., Poppe, M., & Mulder, H. A. (2019). Opportunities to improve resilience in animal breeding programs. Frontiers in Genetics, 9, 692. https://doi.org/10.3389/fgene.2018.00692
Brito, L. F., Bedere, N., Douhard, F., Oliveira, H. R., Arnal, M., Peñagaricano, F., Schinckel, A. P., Baes, C. F., & Miglior, F. (2021). Review: Genetic selection of high-yielding dairy cattle toward sustainable farming systems in a rapidly changing world. Animal, Sustainable Livestock Systems for High-Producing Animals, 15 (Suppl. 1), 100292. https://doi.org/10.1016/j.animal.2021.100292
Brooks, M. B., Harr, K. E., Seelig, D. M., Wardrop, K. J., & Weiss, D. J. (2022). Schalm’s Veterinary Hematology. John Wiley & Sons. https://doi.org/10.1002/9781119500537
Bureau of Agriculture and Fisheries Standards. (2017). Philippine National Standard: Dairy cattle and buffalo—Code of practice—Good animal husbandry practices (PNS/BAFS 199:2017). Department of Agriculture.
Bureau of Agriculture and Fisheries Standards. (2023). Philippine National Standard: Beef cattle and buffalo—Code of practice (COP)—Good animal husbandry practice (GAHP) (PNS/BAFS 200:2023). Department of Agriculture.
Chantip, D., Chooruang, N., Sakuna, K., Thongtem, N., & Chankeaw, W. (2025). Region-specific hematological and biochemical reference intervals for southern Thai fighting bulls. The Thai Journal of Veterinary Medicine, 55(1), 1–11. https://doi.org/10.56808/2985-1130.3822
Chauhan, S. S., Rashamol, V. P., Bagath, M., Sejian, V., & Dunshea, F. R. (2021). Impacts of heat stress on immune responses and oxidative stress in farm animals and nutritional strategies for amelioration. International Journal of Biometeorology, 65(7), 1231–1244. https://doi.org/10.1007/s00484-021-02083-3
Colditz, I. G., & Hine, B. C. (2016). Resilience in farm animals: Biology, management, breeding and implications for animal welfare. Animal Production Science, 56(12), 1961–1983. https://doi.org/10.1071/AN15297
Constable, P. D., Hinchcliff, K. W., Done, S. H., & Gruenberg, W. (2016). Veterinary Medicine: A textbook of the diseases of cattle, horses, sheep, pigs and goats. Elsevier Health Sciences.
Cooke, R. F., Daigle, C. L., Moriel, P., Smith, S. B., Tedeschi, L. O., & Vendramini, J. M. B. (2020). Cattle adapted to tropical and subtropical environments: Social, nutritional, and carcass quality considerations. Journal of Animal Science, 98(2), skaa014. https://doi.org/10.1093/jas/skaa014
Das, R., Sailo, L., Verma, N., Bharti, P., Saikia, J., Imtiwati, & Kumar, R. (2016). Impact of heat stress on health and performance of dairy animals: A review. Veterinary World, 9(3), 260–268. https://doi.org/10.14202/vetworld.2016.260-268
Department of Agriculture Press Office. (2024). Everyone can be a dairy farmer: NDA’s vision for a thriving local dairy industry. Official Portal of the Department of Agriculture. https://www.da.gov.ph/everyone-can-be-a-dairy-farmer-ndas-vision-for-a-thriving-local-dairy-industry/
Department of Science and Technology - Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (DOST-PCAARRD). (2010). Profitability Analysis: 25-Dairy Cow Module. DOST-PCAARRD.
Dimov, D., Penev, T., & Marinov, I. (2020). Temperature-humidity index -an indicator for prediction of heat stress in dairy cows. Veterinarija ir Zootechnika,78(100), 10-5. https://vetzoo.lsmuni.lt/data/vols/2020/78/lt/dimov.pdf
Dominguez, J. M. D., Yebron, M. G. N., Banayo, J. B., Chen, N., Salces, A. J., & Kim, K. S. (2026). Genomic Insights into the Origins, Population Structure, and Local Adaptation of Philippine Visayan Native Cattle. Animals, 16(4), 539. https://doi.org/10.3390/ani16040539
Ekine-Dzivenu, C. C., Mrode, R., Oyieng, E., Komwihangilo, D., Lyatuu, E., Msuta, G., Ojango, J. M. K., & Okeyo, A. M. (2020). Evaluating the impact of heat stress as measured by temperature-humidity index (THI) on test-day milk yield of small holder dairy cattle in a sub-Sahara African climate. Livestock Science, 242, 104314. https://doi.org/10.1016/j.livsci.2020.104314
George, J. W., Snipes, J., & Lane, V. M. (2010). Comparison of bovine hematology reference intervals from 1957 to 2006. Veterinary Clinical Pathology, 39(2), 138–148. https://doi.org/10.1111/j.1939-165X.2009.00208.x
González-Garduño, R., Zaragoza-Vera, C., Chay-Canul, A. J., & Flores-Santiago, E. D. J. (2023). Haematological values in cattle reared in humid and subhumid tropics of Mexico. Tropical Animal Health and Production, 55(4), 251. https://doi.org/10.1007/s11250-023-03664-7
Gupta, S., Sharma, A., Joy, A., Dunshea, F. R., & Chauhan, S. S. (2022). The impact of heat stress on immune status of dairy cattle and strategies to ameliorate the negative effects. Animals, 13(1), 107. https://doi.org/10.3390/ani13010107
Habimana, V., Nguluma, A. S., Nziku, Z. C., Ekine-Dzivenu, C. C., Morota, G., Mrode, R., & Chenyambuga, S. W. (2023). Heat stress effects on milk yield traits and metabolites and mitigation strategies for dairy cattle breeds reared in tropical and sub-tropical countries. Frontiers in Veterinary Science, 10. https://doi.org/10.3389/fvets.2023.1121499
Hartwiger, J., Schären, M., Frahm, J., Kersten, S., Hüther, L., Sauerwein, H., Meyer, U., Breves, G., & Dänicke, S. (2019). Effects of a change from an indoor-based total mixed ration to a rotational pasture system combined with a moderate concentrate feed supply on immunological cell and blood parameters of dairy cows. Veterinary Sciences, 6(2), 47. https://doi.org/10.3390/vetsci6020047
Henry, B. K., Eckard, R. J., & Beauchemin, K. A. (2018). Review: Adaptation of ruminant livestock production systems to climate changes. Animal, 12 (Suppl. 2), s445–s456. https://doi.org/10.1017/S1751731118001301
Jeelani, R., Konwar, D., Khan, A., Kumar, D., Chakraborty, D., & Brahma, B. (2019). Reassessment of temperature-humidity index for measuring heat stress in crossbred dairy cattle of a sub-tropical region. Journal of Thermal Biology, 82, 99–106. https://doi.org/10.1016/j.jtherbio.2019.03.017
Jongbo, A. O., de Borba, L. P., Pereira, R. M. M., Bello, Q. O., Gregoratto, L. L., de Souza, D. P., Adeyeye, O. A., & Vieira, F. M. C. (2026). Heat stress in livestock under tropical climates: Impacts and mitigation strategies. Tropical Animal Health and Production, 58(2), 65. https://doi.org/10.1007/s11250-026-04848-7
Koch, F., Viergutz, T., Kühn, C., & Kuhla, B. (2025). Dynamic immune and molecular responses to chronic heat stress in blood and peripheral blood mononuclear cells of dairy cows. Frontiers in Immunology, 16. https://doi.org/10.3389/fimmu.2025.1633453
Lagare, J. B. (2026). New era for dairy: Philippines to raise new milking cows. Inquirer.net. https://business.inquirer.net/573107/new-era-for-dairy-ph-to-raise-new-milking-cows
Morshedi, M., Yasini, S. P., & Shaghayegh, A. (2022). The effect of daily temperature fluctuation on hematological, biochemical and coagulation parameters in Holstein cattle. Journal of Animal Environment, 14(1), 23–30. http://aejournals.org/index.php/AEJ/article/view/247
Nguyen, N. T., & Bui, T. A. (2026). Age-specific hematological profiles of holstein friesian cattle in vietnamese smallholder farms. Advances in Animal and Veterinary Sciences. https://doi.org/10.17582/journal.aavs/2026/14.1.184.193
Ortega, A. D. S., Mujitaba, M. A., Xayalath, S., Gutierrez, W., Soriano, A. C., & Szabó, C. (2021). Perspectives of the livestock sector in the Philippines: A review. Acta Agraria Debreceniensis, (1), 175–188. https://doi.org/10.34101/actaagrar/1/9101
Philippine Atmospheric, Geophysical and Astronomical Services Administration. (2024). Daily Weather. PAGASA. https://www.pagasa.dost.gov.ph/
Philippine Council for Agriculture, Forestry and Natural Resources Research and Development. (2008). The Philippine Recommendations for Cattle Production (PCARRD Philippines Recommends Series No. 9-C).
Polsky, L., & Von Keyserlingk, M. A. G. (2017). Invited review: Effects of heat stress on dairy cattle welfare. Journal of Dairy Science, 100(11), 8645–8657. https://doi.org/10.3168/jds.2017-12651
Quagliardi, M., Galosi, L., Rossi, G., Roncarati, A., & Gavazza, A. (2024). Reference Intervals (RIs) in veterinary medicine. Acta IMEKO, 13(1), 1–5. https://doi.org/10.21014/actaimeko.v13i1.1615
R Core Team. (2025). R: A language and environment for statistical computing (Version 4.5.2) [Computer software]. R Foundation for Statistical Computing. https://www.R-project.org/
Rajashekaraiah, V., Pallavi, M., Choudhary, A., Bhat, C., Banerjee, P., Ranjithvishal, Laavanyaa, S., & Nithindran, S. (2023). Reactive oxygen species and antioxidant interactions in erythrocytes. In V. Rajashekaraiah (Ed.), The Erythrocyte—A Unique Cell (pp 1-22). IntechOpen. https://doi.org/10.5772/intechopen.107544
Rashamol, V. P., Sejian, V., Bagath, M., Krishnan, G., Archana, P. R., & Bhatta, R. (2018). Physiological adaptability of livestock to heat stress: An updated review. Journal of Animal Behaviour and Biometeorology, 6(3), 62–71. https://doi.org/10.31893/2318-1265jabb.v6n3p62-71
Roland, L., Drillich, M., & Iwersen, M. (2014). Hematology as a diagnostic tool in bovine medicine. Journal of Veterinary Diagnostic Investigation, 26(5), 592–598. https://doi.org/10.1177/1040638714546490
Rubio Lozano, M. S., Ngapo, T. M., & Huerta-Leidenz, N. (2021). Tropical beef: is there an axiomatic basis to define the concept?. Foods, 10(5), 1025. https://doi.org/10.3390/foods10051025
Santos, S. G. C. G. D., Saraiva, E. P., Gonzaga Neto, S., Maia, M. I. L., Lees, A. M., Sejian, V., Maia, A. S. C., Medeiros, G. R. D., & Fonsêca, V. D. F. C. (2022). Heat tolerance, thermal equilibrium and environmental management strategies for dairy cows living in intertropical regions. Frontiers in Veterinary Science, 9, 988775. https://doi.org/10.3389/fvets.2022.988775
Schalm, O. W. (1965). Veterinary Hematology (2nd ed.). Lea & Febiger.
Sejian, V., Bhatta, R., Gaughan, J. B., Dunshea, F. R., & Lacetera, N. (2018). Review: Adaptation of animals to heat stress. Animal, 12 (Suppl. 2), s431–s444. https://doi.org/10.1017/S1751731118001945
Sejian, V., Silpa, M. V., Reshma Nair, M. R., Devaraj, C., Krishnan, G., Bagath, M., Chauhan, S. S., Suganthi, R. U., Fonseca, V. F. C., König, S., Gaughan, J. B., Dunshea, F. R., & Bhatta, R. (2021). Heat stress and goat welfare: adaptation and production considerations. Animals, 11(4), 1021. https://doi.org/10.3390/ani11041021
Slayi, M., & Jaja, I. F. (2025a). Strategies for mitigating heat stress and their effects on behavior, physiological indicators, and growth performance in communally managed feedlot cattle. Frontiers in Veterinary Science, 12. https://doi.org/10.3389/fvets.2025.1513368
Slayi, M., & Jaja, I. F. (2025b). Optimizing rangeland use: Forage selection and grazing patterns of Nguni and Bonsmara cattle across traditional and commercial systems. Veterinary and Animal Science, 28, 100436. https://doi.org/10.1016/j.vas.2025.100436
Thom, E. C. (1959). The Discomfort Index. Weatherwise, 12, 57–61. https://doi.org/10.1080/00431672.1959.9926960
Trantham, N., Kelly, C., Hunt, J. A., Bonnema, H., Stephens, S., & Miller, L. M. (2025). Development and validation of a bovine coccygeal venipuncture model and rubric. Journal of Veterinary Medical Education, e20240111. https://doi.org/10.3138/jvme-2024-0111
Velayudhan, S. M., Brügemann, K., Alam, S., Yin, T., Devaraj, C., Sejian, V., Schlecht, E., & König, S. (2022). Molecular, physiological and hematological responses of crossbred dairy cattle in a tropical savanna climate. Biology, 12(1), 26. https://doi.org/10.3390/biology12010026
Venables, W. N., & Ripley, B. D. (2013). Modern Applied Statistics with S. Springer Science & Business Media.
Whitlock, M. C., & Schluter, D. (2020). The Analysis of Biological Data (3rd ed.). Macmillan Learning.
Xiong, Z., Li, L., Ouyang, K., Qu, M., & Qiu, Q. (2025). Deciphering heat stress mechanisms and developing mitigation strategies in dairy cattle: a multi-omics perspective. Agriculture, 15(14), 1477. https://doi.org/10.3390/agriculture15141477
Yadav, B., Srivastava, A., Yadav, P., Swain, D. K., Anand, M., Yadav, S., & Madan, A. K. (2025). Identification of thermoneutral zone in sahiwal zebu calves in subtropical climate of India. Animals, 15(13), 1830. https://doi.org/10.3390/ani15131830
Yadav, B., Yadav, S., Madan, A. K., Anand, M., Swain, D. K., Pandey, V., & Sirohi, R. (2022). Heat stress responses to increasing temperature humidity index (THI) in lactating Murrah buffalo. Buffalo Bulletin, 41(1), 161–170. https://doi.org/10.56825/bufbu.2022.4112316
Yan, G., Li, H., & Shi, Z. (2021). Evaluation of thermal indices as the indicators of heat stress in dairy cows in a temperate climate. Animals, 11(8), 2459. https://doi.org/10.3390/ani11082459
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