Heat tolerance in cows of British breeds and their crosses with bonsmara under grazing conditions.

Autor: Fedrigo JK; Polo de Desarrollo Universitario (PDU) Agroforestal, Casa de La Universidad de Cerro Largo, Universidad de La República (Udelar), Ruta 26 Km 408, Bañados de Medina, Cerro Largo, Uruguay. Electronic address: jkfedrigo@gmail.com., Báez F; PDU Instituto Superior de La Carne, Sede Tacuarembó, Udelar, Ruta 5, Km 386, Tacuarembó, Uruguay., Cruz RS; Polo de Desarrollo Universitario (PDU) Agroforestal, Casa de La Universidad de Cerro Largo, Universidad de La República (Udelar), Ruta 26 Km 408, Bañados de Medina, Cerro Largo, Uruguay., Viñoles C; Polo de Desarrollo Universitario (PDU) Agroforestal, Casa de La Universidad de Cerro Largo, Universidad de La República (Udelar), Ruta 26 Km 408, Bañados de Medina, Cerro Largo, Uruguay.
Jazyk: angličtina
Zdroj: Journal of thermal biology [J Therm Biol] 2021 Dec; Vol. 102, pp. 103118. Date of Electronic Publication: 2021 Oct 27.
DOI: 10.1016/j.jtherbio.2021.103118
Abstrakt: The objective of this study was to evaluate the influence of the increasing temperature-humidity index (THI) on the body temperature of cows from different breed groups. Vaginal temperature was monitored in cows from two breed groups: a) British breeds (Hereford, Angus and their crosses, n=4); and b) their crosses with Bonsmara (BO, n=6). Vaginal temperature in cows of British breeds was always higher (P < 0.05), and the higher temperature picks coincide with afternoon hours. British cows maintained stable their vaginal temperature if THI was lower than 72.8, but for higher values, they showed linear increases. Moreover, the threshold THI associated to increase in vaginal temperature in British breeds was 72.8. However, vaginal temperature remained unchanged in Bonsmara crosses. The present work suggests that THI greater than 72.8 could affect the body temperature in grazing cattle of British breeds but not its crosses with Bonsmara.
(Copyright © 2021 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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