Assessment of thermal imaging to objectively body condition score mature horses and multiparous gestating beef cows.
Abstract: This study explored whether thermal imaging could provide an objective means of body condition scoring (BCS) horses and multiparous, gestating beef cows. This study consisted of two parts: one part assessed BCS in horses of the Quarter Horse or Thoroughbred breed types while the other evaluated BCS of gestating beef cows. Ground truth BCS were assigned by five to eight trained scorers for each animal. Thermal images were also collected from one or both sides of the body and analyzed for surface temperature. Surface temperature and BCS were evaluated with the whole body, and for five (cows) or seven (horses) specific body regions. Covariates were monitored, including breed, ambient temperature, cloud coverage (%), housing conditions, blanketing status, individual scorer, and scorer's location. Considerable between-scorer variation in BCS assigned was apparent in both species, with 58% to 65% of observations falling within 0.5 BCS of the median. Much of the variability was attributable to scoring the degree of BCS deviation from normal, and 72% to 82% of scores agreed in directional accuracy. Scaled, centered scores within 0.5 units of the median BCS were defined as high-agreement data. Random forest regressions were derived to explore how well thermal-camera-obtained body surface temperature data could be used to estimate BCS of horses and cows using either all available data or the subset of high-agreement data. In both datasets, 15% of observations were used for hyperparameter tuning, 55% for model-training, and 30% for independent evaluation. Unique models were created for each body area assigned a BCS for horses (the neck, shoulder, withers, ribs, loin, tailhead, and overall) or beef cows (the brisket, shoulder, ribs and spine, hooks and pins, and overall). Models estimating horse BCS had lower RMSE (6.71% to 10.4%) and higher accuracy (62.7% to 90.3%) than those estimating cow BCS (RMSE: 6.39% to 15.9%; accuracy: 46.8% to 82.5%). Models derived from all data had higher RMSE (7.76% to 15.9%) and lower accuracy (53.8% to 82.3%) compared with those derived from only high-agreement data (RMSE: 5.80% to 8.18%; accuracy: 66.7% to 90.3%). Overall, thermal imaging shows promise as an objective tool for BCS assignment in both horses and beef cows. However, future refinement of the method for assigning BCS ground truth is important.
© The Author(s) (2025). Published by Oxford University Press on behalf of the American Society of Animal Science.
Publication Date: 2025-09-15 PubMed ID: 41245604PubMed Central: PMC12614166DOI: 10.1093/tas/txaf121Google Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
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Overview
- This research evaluated whether thermal imaging could objectively measure body condition scores (BCS) in mature horses and multiparous gestating beef cows.
- The study compared thermal surface temperature data to traditional, subjective BCS assigned by trained scorers, aiming to develop accurate, automated scoring models.
Study Design and Species
- The research consisted of two parts: one focusing on horses of Quarter Horse or Thoroughbred breeds, and the other on multiparous, gestating beef cows.
- For each animal, multiple trained scorers (five to eight) assigned traditional BCS to serve as a “ground truth” reference.
- Thermal images were captured from one or both sides of the animal bodies to assess surface temperature patterns.
- Body regions analyzed included seven areas for horses (neck, shoulder, withers, ribs, loin, tailhead, overall) and five areas for beef cows (brisket, shoulder, ribs and spine, hooks and pins, overall).
Data Collection and Covariates
- Surface temperature measurements from thermal images were linked with BCS data for both full-body and specific body regions.
- Several covariates were monitored to account for environmental and individual differences, including:
- Breed differences
- Ambient temperature
- Percentage of cloud coverage
- Housing conditions
- Blanketing status
- Individual scorer identity
- Scorer’s physical location
Scorer Variability and Data Agreement
- There was notable variability between scorers in assigning BCS for both horses and cows, reflecting subjectivity in traditional methods.
- Between 58% and 65% of all scores were within 0.5 BCS units of the median score assigned across scorers, showing moderate agreement.
- Most disagreement stemmed from how far the BCS deviated from normal, though 72% to 82% of scores agreed on whether conditions were above or below normal (directional accuracy).
- The researchers defined “high-agreement” data as scores within 0.5 units of the median, isolating more reliable BCS assignments for analysis.
Model Development and Analysis
- Random forest regression models were developed to predict BCS from thermal imaging data.
- Two different model sets were trained for each species:
- One using all available data
- Another restricted to the high-agreement subset of BCS data.
- Data were split into subsets for model tuning (15%), training (55%), and independent evaluation (30%).
- Separate models were built for each body region to explore localized thermal patterns and their relationship with BCS.
Results and Performance Metrics
- Models predicting horse BCS performed better than those for beef cows:
- Horse BCS models showed lower root mean squared error (RMSE) ranging from 6.71% to 10.4% and higher accuracy between 62.7% and 90.3%.
- Cow models had RMSEs from 6.39% to 15.9% and lower accuracies from 46.8% to 82.5%.
- Using high-agreement data improved model accuracy and decreased RMSE:
- High-agreement models had RMSEs between 5.80% and 8.18% and accuracy from 66.7% to 90.3%.
- Models using all data showed higher errors (7.76% to 15.9%) and lower accuracy (53.8% to 82.3%).
Implications and Future Directions
- The study indicates that thermal imaging has strong potential as an objective alternative to subjective body condition scoring for horses and beef cows.
- The technology could improve consistency and reduce observer bias in animal health and management assessments.
- Refining the method for establishing reliable BCS ground truth is critical, as scorer variability impacts model training and accuracy.
- Additional research may focus on improving imaging protocols, integrating environmental factors, and expanding sample sizes or species.
- Ultimately, thermal imaging could support more efficient animal welfare monitoring and nutritional management in livestock production.
Cite This Article
APA
Webster AP, Wright RK, Hammond JB, Kotey NA, Gleason CB, White RR.
(2025).
Assessment of thermal imaging to objectively body condition score mature horses and multiparous gestating beef cows.
Transl Anim Sci, 9, txaf121.
https://doi.org/10.1093/tas/txaf121 Publication
Researcher Affiliations
- School of Animal Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States.
- School of Animal Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States.
- School of Animal Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States.
- School of Animal Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States.
- School of Animal Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States.
- School of Animal Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States.
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