秋季と比較した夏季暑熱環境下におけるヒツジの心拍変動の特徴  [in Japanese] Characteristics of Heart Rate Fluctuations of Sheep in Summer Heat Environment Compared with Those in Autumn  [in Japanese]

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Author(s)

    • 竹村 勇司 TAKEMURA Yuji
    • 東京農工大学農学部生物生産学科 Faculty of Agriculture, Tokyo University of Agriculture and Technology
    • 神谷 充 KAMIYA Mitsuru
    • 東京農工大学農学部生物生産学科 Faculty of Agriculture, Tokyo University of Agriculture and Technology

Abstract

夏季暑熱環境下におけるヒツジの心拍変動の特徴を明らかにする目的で,日本コリデール種の雌雄成畜8頭を用いて秋季を対照に実験を行った。夏季は秋季と比較して,呼吸数,直腸温,皮膚温および被毛表面温が有意に高く,動物は暑熱ストレス状態にあると判断された。心拍間隔標準偏差と心拍間隔変動係数に有意差は認められなかったが,平均心拍間隔は有意に延長した。FFTによる周波数分析では,超低周波数(0.04 Hz未満)と低周波数(0.04以上0.15 Hz未満)帯域のパワーが有意に増大し,トータルパワーに占める超低周波帯域割合の有意な増大と高周波数(0.15以上1.07 Hz未満)帯域割合の有意な減少がみられた。以上の成績から,夏季暑熱下では,体温調節にあずかる呼吸循環器系の適応的機能変化を背景として超低周波数や低周波数帯域で心拍間隔の周期的変動が大きくなる傾向にあるものと推測された。

To investigate the characteristics of the heart rate fluctuations of sheep in a summer heat environment, experiments were performed on eight adult male and female Japanese Corriedale sheep in August (summer heat conditions) and in November (autumn control conditions). High respiration rates (ca. 200/min) and significant increases in the rectal, skin, and fleece temperatures observed at summer experiments indicated heat-stressed conditions of the animals. Mean R-R intervals were significantly lengthened in summer although the standard deviation and the coefficient of variation of R-R intervals were not significantly changed. In the results of spectral analysis of heart rate fluctuations by FFT, powers of the very low frequency (under 0.04 Hz, VLF) and the low frequency (0.04 to under 0.15 Hz, LF) bands were significantly inceased in summer. The power of VLF band expressed as the percentage to the total power was significantly increased in summer, but in contrast, that of the high frequency (0.15 to under 1.07 Hz) band was significantly decreased. It is presumed from the results that the amplitudes of the cyclic fluctuations in heart rate at the very low frequency and the low frequency bands are increased in a summer heat environment in relation to the adaptive thermoregulatory changes in the respirocirculatory functions.

Journal

  • Advances in Animal Cardiology

    Advances in Animal Cardiology 34(1), 6-17, 2001-06

    Japanese Society of Veterinary Cardiology

References:  28

Codes

  • NII Article ID (NAID)
    10008286462
  • NII NACSIS-CAT ID (NCID)
    AN10192925
  • Text Lang
    JPN
  • Article Type
    ART
  • ISSN
    09106537
  • NDL Article ID
    5910861
  • NDL Source Classification
    ZR22(科学技術--農林水産--畜産)
  • NDL Call No.
    Z18-1508
  • Data Source
    CJP  NDL  J-STAGE  JASI 
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