{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T04:31:26Z","timestamp":1787027486306,"version":"build-2736575974"},"reference-count":30,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2025,7,11]],"date-time":"2025-07-11T00:00:00Z","timestamp":1752192000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002241","name":"Japan Science and Technology Agency","doi-asserted-by":"publisher","award":["JPMJTR23R5"],"award-info":[{"award-number":["JPMJTR23R5"]}],"id":[{"id":"10.13039\/501100002241","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Hypocalcemia is common in dairy cows within the first 72 h post-calving, and can be either clinical or subclinical. Early detection is critical, but traditional laboratory tests are time-consuming and cow-side tests remain costly. A classic symptom of hypocalcemia is reduced ear skin temperature, which has been explored as a diagnostic tool in a previous study, but was not recommended at the end. Additionally, ambient temperature was found to strongly influence ear skin temperature, complicating diagnosis. The present study investigates infrared thermography of the ear as a potential non-invasive method for helping in the detection of hypocalcemia in Holstein cows. In order to differ from the previous study, with the goal of improving diagnosis accuracy, this research analyzed the entire ear temperature using infrared imaging software. Ambient temperature was factored in by categorizing samples into two groups based on air temperature: colder (\u22121.6 to 14.6 \u00b0C) and hotter (15.3 to 31.2 \u00b0C). Forty-two cows were monitored during the perinatal period, with blood samples and thermographic images taken twice a day until 48 h after calving. This study found that the median surface temperature of the ear correlated strongly with environmental temperature (r = 0.806, p &lt; 0.001) and weakly with blood ionized calcium levels (r = 0.310, p &lt; 0.01). In colder air temperatures, ear surface temperature was significantly different between healthy and hypocalcemic cows (p = 0.014). Logistic regression models were used to assess ionized calcium status based on different combinations of ear surface temperature, its difference from air temperature, and days in milk. In hotter air temperatures, only ear surface temperature, with no other covariates, was able to generate a valid model (p = 0.029). In colder air temperatures, multiple combinations of those variables generated valid models (p &lt; 0.05), with the difference between ear and air temperature, together with days in milk, performing the best. Thus, this study concluded that ear surface temperature obtained through infrared thermography, while not promising for warmer environments, does show application potential for helping in the detection of hypocalcemia in colder environments.<\/jats:p>","DOI":"10.3390\/ani15142055","type":"journal-article","created":{"date-parts":[[2025,7,11]],"date-time":"2025-07-11T14:22:36Z","timestamp":1752243756000},"page":"2055","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Evaluation of Ear Thermographic Imaging as a Potential Variable for Detecting Hypocalcemia in Postpartum Holstein Dairy Cows"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-0219-5793","authenticated-orcid":false,"given":"Guilherme","family":"Violin","sequence":"first","affiliation":[{"name":"Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-9544-6722","authenticated-orcid":false,"given":"Nanako","family":"Mochizuki","sequence":"additional","affiliation":[{"name":"Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Simon Stephen Abraham","family":"Warju","sequence":"additional","affiliation":[{"name":"Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9382-8960","authenticated-orcid":false,"given":"Megumi","family":"Itoh","sequence":"additional","affiliation":[{"name":"Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2402-4747","authenticated-orcid":false,"given":"Takahiro","family":"Aoki","sequence":"additional","affiliation":[{"name":"Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"323","DOI":"10.4081\/ijas.2005.323","article-title":"Physiological and Pathological Adaptations in dairy cows that may increase susceptibility to periparturient diseases and disorders","volume":"4","author":"Drackley","year":"2005","journal-title":"Ital. J. Anim. Sci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2820","DOI":"10.2527\/1995.7392820x","article-title":"Impact of changes in organic nutrient metabolism on feeding the transition dairy cow","volume":"73","author":"Grummer","year":"1995","journal-title":"J. Anim. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1016\/S0749-0720(15)31053-7","article-title":"Parturient paresis and hypocalcemia in ruminant livestock","volume":"4","author":"Oetzel","year":"1988","journal-title":"Vet. Clin. N. Am. Food Anim. Pract."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1016\/j.tvjl.2007.12.020","article-title":"The Monitoring, prevention, and treatment of milk fever and subclinical hypocalcemia in dairy cows","volume":"176","author":"Goff","year":"2008","journal-title":"Vet. J."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1016\/j.tvjl.2010.03.025","article-title":"Prevalence of subclinical hypocalcemia in dairy herds","volume":"188","author":"Reinhardt","year":"2011","journal-title":"Vet. J."},{"key":"ref_6","unstructured":"Smith, B.P. (2015). Large Animal Internal Medicine, Elsevier. [5th ed.]."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1471","DOI":"10.2460\/javma.1990.197.11.1471","article-title":"Serum ionized calcium concentration in clinically normal dairy cattle, and changes associated with calcium abnormalities","volume":"197","author":"Lincoln","year":"1990","journal-title":"J. Am. Vet. Assoc."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"6542","DOI":"10.3168\/jds.2015-10734","article-title":"Evaluation of ear skin temperature as a cow-side test to predict postpartum calcium status in dairy cows","volume":"99","author":"Venjakob","year":"2016","journal-title":"J. Dairy Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.theriogenology.2017.01.039","article-title":"Association between subclinical hypocalcemia in the first 3 days of lactation and reproductive performance of dairy cows","volume":"94","author":"Caixeta","year":"2017","journal-title":"Theriogenology"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"9321","DOI":"10.3168\/jds.2018-14587","article-title":"Epidemiology of subclinical hypocalcemia in early-lactation holstein dairy cows: The temporal associations of plasma calcium concentration in the first 4 days in milk with disease and milk production","volume":"101","author":"Neves","year":"2018","journal-title":"J. Dairy Sci."},{"key":"ref_11","first-page":"16","article-title":"The Influence of subclinical hypocalcemia on production and reproduction parameters in Israeli dairy herds","volume":"70","author":"Gild","year":"2015","journal-title":"Isr. J. Vet. Med."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"9285","DOI":"10.3168\/jds.2017-12971","article-title":"Short communication: Relationship between methods for measurement of serum electrolytes and the relationship between ionized and total calcium and neutrophil oxidative burst activity in early postpartum dairy cows","volume":"100","author":"Leno","year":"2017","journal-title":"J. Dairy Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"7001","DOI":"10.3168\/jds.2013-6901","article-title":"Subclinical hypocalcemia, plasma biochemical parameters, lipid metabolism, postpartum disease, and fertility in postparturient dairy cows","volume":"96","author":"Chamberlin","year":"2013","journal-title":"J. Dairy Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1111\/vcp.12705","article-title":"Evaluation of the i-STAT analyzer for determination of ionized calcium concentrations in bovine blood","volume":"48","author":"Yilmaz","year":"2019","journal-title":"Vet. Clin. Pathol"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"874","DOI":"10.3168\/jds.2013-7408","article-title":"Effect of induced subclinical hypocalcemia on physiological responses and neutrophil function in dairy cows","volume":"97","author":"Martinez","year":"2014","journal-title":"J. Dairy Sci."},{"key":"ref_16","unstructured":"Constable, P.D., Hinchcliff, K.W., Done, S.H., Gr\u00fcnberg, W., and Constable, P.D. (2017). Veterinary Medicine: A Textbook of the Diseases of Cattle, Horses, Sheep, Pigs and Goats, Elsevier. [11th ed.]."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2526","DOI":"10.2527\/1997.7592526x","article-title":"Body temperature and endocrine interactions before and after calving in beef cows","volume":"75","author":"Lammoglia","year":"1997","journal-title":"J. Anim. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"5053","DOI":"10.3168\/jds.2011-4484","article-title":"Validity of prepartum changes in vaginal and rectal temperature to predict calving in dairy cows","volume":"94","author":"Burfeind","year":"2011","journal-title":"J. Dairy Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1016\/S0749-0739(17)30502-3","article-title":"Thermography as an aid to the clinical lameness Evaluation","volume":"7","author":"Turner","year":"1991","journal-title":"Vet. Clin. N. Am. Equine Pract."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"R33","DOI":"10.1088\/0967-3334\/33\/3\/R33","article-title":"Infrared thermal imaging in medicine","volume":"33","author":"Ring","year":"2012","journal-title":"Physiol. Meas."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1169","DOI":"10.1108\/HFF-03-2011-0054","article-title":"Effects of concavity level on heat loss, effectiveness and efficiency of a longitudinal fin exposed to natural convection and radiation","volume":"23","author":"Cuce","year":"2013","journal-title":"Int. J. Numer. Methods Heat Fluid Flow"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Meisfjord J\u00f8rgensen, G.H., Mejdell, C.M., and B\u00f8e, K.E. (2020). Effects of hair coat characteristics on radiant surface temperature in horses. J. Therm. Biol., 87.","DOI":"10.1016\/j.jtherbio.2019.102474"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"144","DOI":"10.1080\/00480169.1987.35418","article-title":"The anatomy of the auricular conchae of cattle, sheep and deer","volume":"35","author":"Rashid","year":"1987","journal-title":"N. Z. Vet. J."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1017\/S0021859600045196","article-title":"The effect of environmental temperature and humidity on the ear temperatures of Ayrshire calves","volume":"45","author":"Beakley","year":"1955","journal-title":"J. Agric. Sci."},{"key":"ref_25","unstructured":"National Research Council (1971). A Guide to Environmental Research on Animals."},{"key":"ref_26","unstructured":"Yousef, M.K. (1985). Stress Physiology in Livestock. Volume I. Basic Principles, CRC Press."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"712","DOI":"10.2527\/2006.843712x","article-title":"Environmental factors influencing heat stress in feedlot cattle","volume":"84","author":"Mader","year":"2006","journal-title":"J. Anim. Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/j.applanim.2007.11.003","article-title":"The ear skin temperature as an indicator of the thermal comfort of pigs","volume":"113","author":"Andersen","year":"2008","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1292\/jvms.21-0320","article-title":"Improving the accuracy of estimating blood calcium concentration in holstein cows using electrocardiographic variables","volume":"84","author":"Itoh","year":"2022","journal-title":"J. Vet. Med. Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1007\/s10439-018-02115-x","article-title":"Validity of skin, oral and tympanic temperatures during exercise in the heat: Effects of wind and sweat","volume":"47","year":"2019","journal-title":"Ann. Biomed. Eng."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/15\/14\/2055\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:08:48Z","timestamp":1760033328000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/15\/14\/2055"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,7,11]]},"references-count":30,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2025,7]]}},"alternative-id":["ani15142055"],"URL":"https:\/\/doi.org\/10.3390\/ani15142055","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,7,11]]}}}