02720naa a2200361 a 450000100080000000500110000800800410001902400560006010000210011624501830013726000090032052016440032965000150197365000210198865000130200965000190202265000180204165000150205965000110207465000090208565300190209465300180211365300250213170000200215670000190217670000220219570000190221770000180223670000180225470000160227270000160228877300540230421549772023-08-22       2023    bl uuuu     u00u1 u    #d7 ahttps://doi.org/10.1016/j.jtherbio.2023.1036282DOI1 aGUADAGNIN, A. R.  aAssessment of heat production and methane emission using infrared thermography in lactating Holstein and Gyrolando-F1 (½ Holstein ½ Gyr) crossbreed cows.h[electronic resource]  c2023  aInfrared thermography (IRT) is a non-invasive and efficient tool to detect changes in the animal?s body surface temperature, which is directly associated with the animal?s energy loss. Methane emission represents a significant energy loss, particularly in ruminants, as well as heat production. Therefore, the aim of this study was to correlate skin temperature measured using IRT with heat production (HP) and methane emission in lactating Holstein and crossbred ½ Holstein x ½ Gyr (Gyrolando-F1) cows. Six Gyrolando-F1 and four Holstein cows, all primiparous, at mid lactation were used to evaluate daily HP and methane emission using indirect calorimetry in respiratory chambers. Thermographic images were taken at anus, vulva, ribs (on the right side), left flank, right flank, right front foot, upper lip, masseter and eye; IRT was performed every hour during 8 h after the morning feeding. Cows received the same diet ad libitum. Daily methane emission was positively correlated with IRT taken at the right front foot 1 h after feeding in Gyrolando-F1 cows (r = 0.85, P &lt 0.05) and with IRT taken at the eye 5 h after feeding in Holstein cows (r = 0.88, P &lt 0.05). HP was positively correlated with IRT taken at the eye 6 h after feeding in Gyrolando-F1 cows (r = 0.85, P &lt 0.05) and with IRT taken at the eye 5 h after feeding in Holstein cows (r = 0.90, P &lt 0.05). Infrared thermography was positively correlated with HP and methane emission in both Holstein and Gyrolando-F1 lactating cows, although the anatomical points and times of image acquisition yielding the greatest correlation coefficients varies among breeds.  aDairy cows  aGreenhouse gases  aGado Gir  aGado Holandês  aGado Leiteiro  aLactação  aMetano  aVaca  aBioenergética  aBioenergetics  aPrecision technology1 aMATIELLO, J. P.1 aRIBEIRO, R. S.1 aPEREIRA, L. G. R.1 aMACHADO, F. S.1 aTOMICH, T. R.1 aCAMPOS, M. M.1 aHEISLER, G.1 aFISCHER, V.  tJournal of Thermal Biologygv. 115, 103628, 2023.