title: Technological, environmental and biological factors: referent variance values for infrared imaging of the bovine.
abstract: BACKGROUND
  Despite its variety of potential applications, the wide implementation of infrared technology in cattle production faces technical, environmental and biological challenges similar to other indicators of metabolic state. Nine trials, divided into three classes (technological, environmental and biological factors) were conducted to illustrate the influence of these factors on body surface temperature assessed through infrared imaging.
  
  
  RESULTS
  Evaluation of technological factors indicated the following: measurements of body temperatures were strongly repeatable when taken within 10 s; appropriateness of differing infrared camera technologies was influenced by distance to the target; and results were consistent when analysis of thermographs was compared between judges. Evaluation of environmental factors illustrated that wind and debris caused decreases in body surface temperatures without affecting metabolic rate; additionally, body surface temperature increased due to sunlight but returned to baseline values within minutes of shade exposure. Examination/investigation/exploration of animal factors demonstrated that exercise caused an increase in body surface temperature and metabolic rate. Administration of sedative and anti-sedative caused changes on body surface temperature and metabolic rate, and during late pregnancy a foetal thermal imprint was visible through abdominal infrared imaging.
  
  
  CONCLUSIONS
  The above factors should be considered in order to standardize operational procedures for taking thermographs, thereby optimizing the use of such technology in cattle operations.
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Guelph, ON N1G 2W1 Canada ; Department of Plant and Animal Sciences, Dalhousie University, Truro, NS B2N 5E3 Canada.
authors.forename: Yuri R
authors.initials: YR
authors.lastname: Montanholi
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Guelph, ON N1G 2W1 Canada.
authors.forename: Melissa
authors.initials: M
authors.lastname: Lim
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Guelph, ON N1G 2W1 Canada.
authors.forename: Alaina
authors.initials: A
authors.lastname: Macdonald
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Guelph, ON N1G 2W1 Canada ; Monsanto, Headingley, MB R3T 6E3 Canada.
authors.forename: Brock A
authors.initials: BA
authors.lastname: Smith
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge, AB T1J 4B1 Canada ; Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4Z6 Canada.
authors.forename: Christy
authors.initials: C
authors.lastname: Goldhawk
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge, AB T1J 4B1 Canada.
authors.forename: Karen
authors.initials: K
authors.lastname: Schwartzkopf-Genswein
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Guelph, ON N1G 2W1 Canada ; Invermay Agricultural Centre, AgResearch Limited, Mosgiel, 9053 New Zealand.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Miller
keywords: Body heat loss; Convective heat loss; Infrared imaging; Oxygen consumption; Pharmacodynamics