Title:	Relationship between physical attributes and heat stress in dairy cattle from different genetic groups.
Authors:	ALFONZO, E. P. SILVA, M. V. G. B. SANTOS, D. D. dos STUMPF, M. T. DALCIN, V. C. KOLLING, G. FISCHER, V. McMANUS, C. M.
Affiliation:	E. P. ALFONZO, UFRGS; MARCOS VINICIUS GUALBERTO B SILVA, CNPGL; Daltro D. dos Santos, UFRGS; M. T. STUMPF, UFRGS; V. C. DALCIN, UFRGS; G. KOLLING, UFRGS; V. FISCHER, UFRGS; M. C. McMANUS, UFRGS; UnB.
Date Issued:	2015
Citation:	International Journal of Biometeorology, v. 60, n. 2, p. 245-353, 2015.
Description:	Dairy cattle raised under harsh conditions have to adapt and prevent heat stress. The aim of this study was to evaluate physical characteristics and their association with heat tolerance in different genetic groups of dairy cattle. Thickness of the skin and coat, length and number of hairs, body measurements, as well as physiological parameters and body temperatures by infrared thermography were determined in 19 Holstein and 19 Girolando (½ and ¾ Holstein) cows. The Holstein cattle were less tolerant to heat stress than Girolando (GH50 and GH75 Holstein), because of the difficulty in dissipating heat due to the larger body size, as well as thicker and longer hairs. The correlations between physical characteristics, physiological parameters, and thermographic measurements prove to be inconsistent among genetic groups and therefore are not predictive of heat tolerance, while the regressions of morphometric characteristics on physiological and thermographic measures were not significant. Thus, the physical characteristics were not good predictors of physiological indices and thermographic temperature and so should not be used.
NAL Thesaurus:	thermography
Keywords:	Coat and cows Tolerance
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CNPGL)