Acta Scientiarum: Animal Sciences (Apr 2024)

Physical characteristics of the hair coat of sows raised in free-range systems in a tropical environment

  • Sheila Tavares Nascimento,
  • João Victor do Nascimento Mós,
  • Luci Sayori Murata,
  • Vinicius Machado dos Santos,
  • Antonio José Steidle Neto,
  • Evandro Menezes de Oliveira,
  • Alex Sandro Campos Maia,
  • Bruno Emanoel Teixeira,
  • Raquel Parizotto,
  • Luana Freitas Silva

DOI
https://doi.org/10.4025/actascianimsci.v46i1.63533
Journal volume & issue
Vol. 46, no. 1

Abstract

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The aim of this study was to investigate the hair coat characteristics of sows raised in a free-range system in a tropical climate and assess associations with effective radiative properties and thermal conductivity. Bristles were collected from December 2017 to April 2018 and evaluated for diameter (mm), length (mm), and density (bristles per cm2). From these data, the effective thermal conductivity, absorptivity, transmissivity, and reflectivity of the hair coat were determined. Sows were separated into four groups according to skin pigmentation and color parameters. The environment was characterized with regard to average air temperature (°C), relative humidity (%), and shortwave radiation (W m-2). The data were analyzed by repeated measures analysis. Bristle length (33 mm) and density (10 bristles cm-2) were lower in summer than in colder months (48 mm and 20 bristles cm-2, respectively). Effective absorptivity was higher and transmittance was lower in more pigmented sows, demonstrating a connection with protection against solar radiation. Therefore, the combination of a pigmented and dense coat seems to be ideal for pigs reared in free-range systems.

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