170942 20260430151735.0 doi 10.1007/s00484-026-03199-0 sideral 148999 ART-2026-148999 eng Abecia, José-Alfonso Universidad de Zaragoza (orcid)0000-0003-2827-3054 Biologger-based monitoring of body temperature, heart rate, and heart rate variability in Lidia cattle: relationships with environmental conditions 2026 An understanding of how Lidia cattle (Bos taurus) physiologically adapt to natural environmental conditions is essential for assessing their welfare and resilience in extensive systems. This study documented the circadian and short-term responses of Lidia cows to natural summer conditions based on data from subcutaneous biologgers that continuously recorded body temperature (T), heart rate (HR), and HR variability (HRV). Four cows were monitored for 10 consecutive days, and ambient T and relative humidity were recorded simultaneously, which were used to calculate the Temperature–Humidity Index (THI). Both T and HR exhibited clear diurnal rhythms, increasing during the day and peaking in the evening, but HRV indices (SDNN and RMSSD) were highest at night, which reflected highest parasympathetic activity at night. Cosinor analyses confirmed strong rhythmicity in body T (robustness = 0.84; circadian index > 3) and moderate rhythmicity in HR and HRV. Physiological responses to heat stress exhibited distinct temporal delays; i.e., HR increased approximately 3 h after increases in THI, body T peaked after about 4.5 h, and HRV reached its minimum 3.5–4 h later. Those results indicate that autonomic and thermal adjustments unfolded gradually and with measurable lags following changes in environmental conditions. Despite pronounced daily variations in ambient conditions, Lidia cattle maintained stable body T rhythms and clear circadian organization, which reflected their high thermotolerance and capacity to adjust to Mediterranean summer environments. info:eu-repo/grantAgreement/ES/UZ/IUCA info:eu-repo/semantics/closedAccess All rights reserved http://www.europeana.eu/rights/rr-f/ info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Iglesias, Pablo Plaza, Javier Nieto, Jaime Morales, Luis Palacios, Carlos Alonso, Marta Elena Lomillos, Juan Manuel 2008 700 Universidad de Zaragoza Dpto. Produc.Animal Cienc.Ali. Área Producción Animal 70, 4 (2026), 127 [12 pp.] Int. j. biometeorol. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 0020-7128 2513767 http://zaguan.unizar.es/record/170942/files/texto_completo.pdf Versión publicada info:eu-repo/date/embargoEnd/2027-04-15 2349395 http://zaguan.unizar.es/record/170942/files/texto_completo.jpg?subformat=icon icon Versión publicada info:eu-repo/date/embargoEnd/2027-04-15 oai:zaguan.unizar.es:170942 articulos driver 2026-04-30-13:57:34 ARTICLE