Using unmanned aerial vehicles to record behavioral and physiological indicators of heat stress in cattle on feedlot and pasture

Physiological and behavioral indicators of heat stress in cattle are time labor-intensive to measure, difficult observe extensive pasture settings. We proposed record respiration rate standing behavior using unmanned aerial vehicles. Videos were recorded above steers on feedlot the morning (0830 – 1130) afternoon (1400 1700) over ten days between July 25 Aug 10, cows nine 19 29. In feedlot, video recordings 925 individuals (264 black-coated, 413 red, 248 white) obtained, varying breed which included Black Angus, Hereford, Charolais, Canadian Speckle Park, Simmental. On pasture, 267 (116 Angus 151 Hereford) obtained. Observer software was used analyze videos. Respiration highest black cattle, followed by red then white cattle. Coat color did not affect pasture; temperatures lower than feedlots effect coat may manifest until a certain ambient or globe temperature threshold. The probability that would be increased with load index