Physiological responses and animal behavior in Bonsmara-Hereford crosses vs. Hereford purebred on environment stress

  • Paula Alicia Batista Taborda University of the Republic of Uruguay; Faculty of Agriculture; Dept. of Animal Production and Pastures
  • Celmira Tomasina Saravia University of the Republic of Uruguay; Faculty of Agriculture
  • Ana Carolina Espasandin University of the Republic of Uruguay; Faculty of Agriculture; Dept. of Animal Production and Pastures
Keywords: beef cattle, grazing behavior, thermoregulation, bioclimatology

Abstract

Adaptative traits (rectal temperature-RT, respiratory rate-RR) and grazing behavior (Grazing, Ruminating and Rest time, and Sun or Shade time) of Bonsmara-Hereford crossbred-BH, n = 15, and purebred Hereford-HH, n = 18, yearling heifers, in a grazing system of Uruguay. Environment characterization was made using THIadjusted by radiation and wind speed (no, mild, and severe heat weaves), and the comprehensive climatic index-CCI (no, middle, moderate and severe stress). Adaptative traits were measured twice a day, weekly, in two consecutive days in summer and winter at 08h00 and 16h00. Grazing behavior was observed from 07h00 to 21h00 each 600 s twice in summer. The records were analyzed using a mixed model. Significant effect of genotype was observed in mild heat waves for RR and RT in the afternoon (BH lower than HH). For CCI in a.m., the RR was lower than HH in BH in severe stress, while in p.m., the RR was lower in all of CCI levels. RT in p.m. in moderate and severe was lower in BH than in HH. In winter, no differences were found. In grazing behavior, HH rests longer than BH doe; also, HH spends more time in the shade (34 %) than BH does (22 %). BH genotype showed better thermoregulation and grazing behavior at higher temperatures compared to HH.

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Published
2018-12-01
How to Cite
Taborda, P., Saravia, C., & Espasandin, A. (2018). Physiological responses and animal behavior in Bonsmara-Hereford crosses vs. Hereford purebred on environment stress. Scientia Agricola, 75(6), 479-485. https://doi.org/10.1590/1678-992x-2017-0042
Section
Animal Science and Pastures