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Short communication: Upper critical temperature-humidity index for dairy calves based on physiological stress variables

Authors :
N. Boros
Fruzsina Luca Kézér
K. Nagy
Levente Kovács
Péter Póti
Source :
Journal of dairy science. 103(3)
Publication Year :
2019

Abstract

In this study, upper critical values of the temperature-humidity index (THI) were determined in Holstein bull calves (n = 16) based on noninvasive physiological variables. Meteorological and animal-based data were recorded for a 4-d period following a 24-h habituation. The estimated upper critical THI values based on the assessment of respiratory rate, rectal temperature, ear temperature, heart rate, and salivary cortisol concentrations were 82.4, 88.1, 83.0, 78.3, and 88.8, respectively. We inferred that welfare of young calves may be compromised above a THI of 78 and that calves experience significant heat stress above a THI of 88. Based on the present findings, upper critical THI should be considered to minimize the duration of impaired welfare during summer heat stress episodes.

Details

ISSN :
15253198
Volume :
103
Issue :
3
Database :
OpenAIRE
Journal :
Journal of dairy science
Accession number :
edsair.doi.dedup.....3bdad80f440564e224181a81142c0d54