000153167 001__ 153167 000153167 005__ 20251017144643.0 000153167 0247_ $$2doi$$a10.1016/j.cbpa.2025.111849 000153167 0248_ $$2sideral$$a143629 000153167 037__ $$aART-2025-143629 000153167 041__ $$aeng 000153167 100__ $$0(orcid)0000-0003-2827-3054$$aAbecia, José A.$$uUniversidad de Zaragoza 000153167 245__ $$aTriaxial accelerometers and subcutaneous biologgers as tools to record diurnal and nocturnal changes in locomotor activity, body temperature, heart rate, and heart rate variability in melatonin-treated lambs (Ovis aries) 000153167 260__ $$c2025 000153167 5060_ $$aAccess copy available to the general public$$fUnrestricted 000153167 5203_ $$aThe study of growth and development of lambs (Ovis aries) is essential in sheep farming, and melatonin plays an important role in the physiology of growing lambs. The effects of an exogenous melatonin treatment on several physiological characteristics in fattening lambs at weaning were studied. Eight lambs were assigned to one of two groups; those that did (melatonin group, n = 4) or did not (no-melatonin group, n = 4) receive two subcutaneous melatonin implants at weaning. At the end of the fattening period, to quantify locomotor activity (LA), each lamb was fitted with a triaxial accelerometer, for 7 days. Simultaneously, lambs received a surgically implanted subcutaneous temperature (T) and heart rate (HR) biologger, which was programmed to record data every 5 min. HR variability (HRV) variables (SDNN, the standard deviation of normal-to-normal R-R intervals, and RMSSD, the root mean square of consecutive deviations between normal heartbeats) were measured. All of the variables exhibited 24-h circadian rhythms. Time of day (daytime vs. nighttime) had a significant effect on LA, T, and HR, but considering both treatment with melatonin and time, differences between time for these variables were only observed in melatonin-treated lambs. Exogenous melatonin did not affect LA or T, but melatonin-treated lambs had lower HR, SDNN, and RMSSD than did non-treated lambs. In conclusion, the use of subcutaneous biologgers and triaxial accelerometers in growing lambs demonstrated circadian rhythms in LA, T, HR, and HRV, and melatonin treatment negatively affected HRV, but its effects on the other physiological variables differed between day and night. 000153167 536__ $$9info:eu-repo/grantAgreement/EC/HORIZON EUROPE/101136346/EU/European Partnership Animal health and Welfare/EUPAHW 000153167 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc-nd$$uhttps://creativecommons.org/licenses/by-nc-nd/4.0/deed.es 000153167 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion 000153167 700__ $$aManenti, Isabella 000153167 700__ $$aViola, Irene 000153167 700__ $$aToschi, Paola 000153167 700__ $$aPalacios, Carlos 000153167 700__ $$aCanto, Francisco 000153167 700__ $$aMiretti, Silvia 000153167 7102_ $$12008$$2700$$aUniversidad de Zaragoza$$bDpto. Produc.Animal Cienc.Ali.$$cÁrea Producción Animal 000153167 773__ $$g305 (2025), 111849 [8 pp.]$$pComp. biochem. physiol., Part A Mol. integr. physiol.$$tCOMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY$$x1095-6433 000153167 8564_ $$s2539547$$uhttps://zaguan.unizar.es/record/153167/files/texto_completo.pdf$$yVersión publicada 000153167 8564_ $$s2599738$$uhttps://zaguan.unizar.es/record/153167/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada 000153167 909CO $$ooai:zaguan.unizar.es:153167$$particulos$$pdriver 000153167 951__ $$a2025-10-17-14:33:08 000153167 980__ $$aARTICLE