title: Infrared Thermography to Evaluate Heat Tolerance in Different Genetic Groups of Lambs.
abstract: Heat stress is considered a limiting factor for sheep production. We used information from physiological characteristics linked to heat tolerance to determine whether infrared thermography temperatures were able to separate groups of animals and determine the most important variables in this differentiation. Forty-eight four-month-old male lambs from eight genetic groups were used. Physiological (rectal temperature-RT, heart rate-HR, respiratory rate-RR) and blood traits, infrared thermography temperatures, heat tolerance indices, body measurements, weight and carcass traits were measured. Statistical analyses included variance, correlations, factor, discrimination and regression. Observing the correlations between physiological characteristics (RT, RR and HR) with temperatures measured by infrared thermography, regions for further studies should include the mean temperature of flank, nose and rump. Results show that there are strong relationships between thermograph measurements and RR, RT and HR in lambs, which are suggested to be directly correlated with heat tolerance capacity of the different genetic groups evaluated in this study. The assessment of body surface temperature measured by the thermograph could be used as a noninvasive tool to assess heat tolerance of the animals.
authors.affiliation: Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília, Brasília 70910-900, DF, Brasil. concepta.mcmanus@ufrgs.br.|Departamento de Zootecnia, Universidade Federal do Rio Grande do Sul, Porto Alegre 91540-000, Brasil. concepta.mcmanus@ufrgs.br.
authors.forename: Concepta
authors.initials: C
authors.lastname: McManus
authors.affiliation: Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília, Brasília 70910-900, DF, Brasil. eliandrabianchini@gmail.com.
authors.forename: Eliandra
authors.initials: E
authors.lastname: Bianchini
authors.affiliation: Instituto Federal de Educação, Ciência e Tecnologia Goiano-Campus Iporá, Iporá 76200-000, Brasil. pradopaim@hotmail.com.
authors.forename: Tiago do Prado
authors.initials: Tdo P
authors.lastname: Paim
authors.affiliation: Escola de Veterinária, Universidade Federal de Goiás, Goiânia, Goiás Paulo 74690-900, Brasil. flaviamedvet@yahoo.com.br.
authors.forename: Flavia Gontijo
authors.initials: FG
authors.lastname: de Lima
authors.affiliation: Departamento de Zootecnia, Universidade Federal do Rio Grande do Sul, Porto Alegre 91540-000, Brasil. jose.braccini@ufrgs.br.
authors.forename: José Braccini
authors.initials: JB
authors.lastname: Neto
authors.affiliation: Escola de Veterinária, Universidade Federal de Goiás, Goiânia, Goiás Paulo 74690-900, Brasil. castanheira_m@hotmail.com.
authors.forename: Marlos
authors.initials: M
authors.lastname: Castanheira
authors.affiliation: Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília, Brasília 70910-900, DF, Brasil. isildinha@gmail.com.
authors.forename: Geisa Isilda Ferreira
authors.initials: GI
authors.lastname: Esteves
authors.affiliation: Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília, Brasília 70910-900, DF, Brasil. cajug29@gmail.com.
authors.forename: Caio Cesar
authors.initials: CC
authors.lastname: Cardoso
authors.affiliation: Departamento de Zootecnia, Universidade Federal do Rio Grande do Sul, Porto Alegre 91540-000, Brasil. vanessacdalcin@yahoo.com.br.
authors.forename: Vanessa Calderaro
authors.initials: VC
authors.lastname: Dalcin
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001831:Body Temperature / Q000502:physiology; D001938:Brazil; D016000:Cluster Analysis; D006358:Hot Temperature; D007259:Infrared Rays; D008297:Male; D025341:Principal Component Analysis; D012044:Regression Analysis; D056152:Respiratory Rate / Q000502:physiology; D012756:Sheep / Q000235:genetics* / Q000502:physiology*; D013817:Thermography / Q000379:methods*
keywords: adaptation; genetic resources; naturalized breeds; temperature; tropical