Basal body temperature as a biomarker of reproductive state in ewes: A multi‐method comparison
- 1Faculty of Environmental and Agricultural Sciences University of Salamanca Salamanca Spain
- 2Institute of Research in Environmental Sciences of Aragón (IUCA), University of Zaragoza Zaragoza Spain
Abstract
This study quantified body temperature dynamics throughout reproductive stages in crossbred ewes based on complementary monitoring techniques. Five ewes from a semi‐extensive farming system were included in two sub‐trials: animals were first assessed in the prepubertal stage and, subsequently, an oestrous cycle was induced by intravaginal progesterone sponges followed by eCG and prostaglandin; oestrous was confirmed by serum progesterone. Temperatures were recorded in five stages (prepubertal, pubertal, sponge, post‐sponge, oestrous) based on eight measurements: rectal (RT), subcutaneous biologger (SCT) and infrared thermography (IRT) of vulva/axilla that were obtained either as unprocessed maximum pixel or as FLIR‐processed maximum/mean. A linear mixed‐effects model that included Method, Stage and their interaction indicated strong global effects (all p < 0.001). Estimated marginal means revealed a clear physiological trajectory: temperatures were highest in the prepubertal stage, generally decreased from the prepubertal stage towards the treatment‐related stages, although the timing of the minimum value depended on the measurement method. Among the methods, RT yielded the highest estimated mean temperatures and the most stable measurements, SCT recorded slightly lower temperatures, vulvar FLIR‐processed metrics were able to detect stage‐related thermal changes, and axillary measures, especially unprocessed maxima, were more variable and environmentally sensitive. In general, thermal monitoring identified the expected reproductive‐stage patterns. RT and SCT provided the most stable detection of reproductive‐stage temperature changes, whereas vulvar FLIR‐processed thermography represented the most promising non‐invasive alternative. Axillary thermography was more variable and appeared to be more susceptible to environmental influences.
Related
- Individual variation in glucocorticoid plasticity to temperature is not associated with reproductive success in a wild songbird population
- Tracking interannual temperature variation: phenological plasticity and reproductive stability in tropical hornbills
- Association of Sex Hormone-Binding Globulin with Glycated Hemoglobin and Multidimensional Biomarker Structure in Reproductive-Age Women: An Analysis Based on NHANES 2021--2023
- In Situ Reproductive Bioassay with Caged Gammarus fossarum (Crustacea): Part 2—Evaluating the Relevance of Using a Molt Cycle Temperature‐Dependent Model as a Reference to Assess Toxicity in Freshwater Monitoring
- Urinary kisspeptin as a non-invasive reproductive biomarker in crossbred cattle and black Bengal does
BibTeX
@article{perezgarcia2026basal,
title = {{Basal body temperature as a biomarker of reproductive state in ewes: A multi‐method comparison}},
author = {E Pérez‐García and J Nieto de la Losa and JA Abecia and J Plaza and C Palacios Riocerezo},
journal = {Australian Veterinary Journal},
year = {2026},
month = jul,
doi = {10.1111/avj.70112},
url = {https://doi.org/10.1111/avj.70112},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Basal body temperature as a biomarker of reproductive state in ewes: A multi‐method comparison
AU - E Pérez‐García
AU - J Nieto de la Losa
AU - JA Abecia
AU - J Plaza
AU - C Palacios Riocerezo
PY - 2026
DA - 2026/07/04
JO - Australian Veterinary Journal
DO - 10.1111/avj.70112
UR - https://doi.org/10.1111/avj.70112
AB - This study quantified body temperature dynamics throughout reproductive stages in crossbred ewes based on complementary monitoring techniques. Five ewes from a semi‐extensive farming system were included in two sub‐trials: animals were first assessed in the prepubertal stage and, subsequently, an oestrous cycle was induced by intravaginal progesterone sponges followed by eCG and prostaglandin; oestrous was confirmed by serum progesterone. Temperatures were recorded in five stages (prepubertal, pubertal, sponge, post‐sponge, oestrous) based on eight measurements: rectal (RT), subcutaneous biologger (SCT) and infrared thermography (IRT) of vulva/axilla that were obtained either as unprocessed maximum pixel or as FLIR‐processed maximum/mean. A linear mixed‐effects model that included Method, Stage and their interaction indicated strong global effects (all p < 0.001). Estimated marginal means revealed a clear physiological trajectory: temperatures were highest in the prepubertal stage, generally decreased from the prepubertal stage towards the treatment‐related stages, although the timing of the minimum value depended on the measurement method. Among the methods, RT yielded the highest estimated mean temperatures and the most stable measurements, SCT recorded slightly lower temperatures, vulvar FLIR‐processed metrics were able to detect stage‐related thermal changes, and axillary measures, especially unprocessed maxima, were more variable and environmentally sensitive. In general, thermal monitoring identified the expected reproductive‐stage patterns. RT and SCT provided the most stable detection of reproductive‐stage temperature changes, whereas vulvar FLIR‐processed thermography represented the most promising non‐invasive alternative. Axillary thermography was more variable and appeared to be more susceptible to environmental influences.
SN - 0005-0423
SN - 1751-0813
ER -