Acta Veterinaria et Zootechnica Sinica ›› 2020, Vol. 51 ›› Issue (6): 1342-1353.doi: 10.11843/j.issn.0366-6964.2020.017

• ANIMAL NUTRITION AND FEEDS • Previous Articles     Next Articles

Evaluation of Heat Stress of Housed Sheep and Correlation between Temperature-humidity Parameter and Physiological Parameter of Sheep in Hebei Province

ZHAO Juanjuan1, FENG Man2, SUN Xinsheng3, LU Dongmei4, WANG Chao1, ZHAO Shoupei1, CHE Dalu1, LI Xuemei1, GAO Yuhong1*   

  1. 1. College of Animal Science and Technology, Hebei Agricultural University, Baoding 071001, China;
    2. Animal Husbandry Research Institute, Chengde Academy of Agriculture and Forestry, Chengde 067000, China;
    3. College of Information Science and Technology, Hebei Agricultural University, Baoding 071001, China;
    4. Agricultural Bureau of Baoding, Baoding 071001, China
  • Received:2019-12-10 Online:2020-06-25 Published:2020-06-23

Abstract: This experiment was conducted to study heat stress on sheep in three regions (Yanshan Mountain of Hebei North, Taihang Mountain and Central-South plain) of Hebei province in summer, and the correlation was also investigated between ambient temperature-humidity parameters and physiological parameters of housed sheep in order to provide theoretical basis for improving the environment of sheep shed. Twelve large-scale sheep farms in 3 regions were selected to automatically detect and record the ambient temperature and relative humidity of sheep sheds in summer for 2 months. In the mean time, the rectal temperature and respiratory rate of sheep in each farm were detected. The results showed that the average daily temperature in sheep sheds of Yanshan Mountain of Hebei North, Taihang Mountain and Central-South plain reached 24.3, 28.5, and 28.7℃, and the temperature-humidity index (THI) was 72.40, 79.91, and 79.47, respectively. These results suggested that sheep in Yanshan Mountain of Hebei North region were suffering from mild heat stress, while sheep in the other two regions were suffering from moderate or serious heat stress. Thus, the heat stress prevention of sheep in summer in Hebei province should be paid more attention, and it was urgent to strengthen the heat prevention and cooling measures of sheep shed in summer. From physiological parameters of sheep in 3 regions, the range of rectal temperature was from 39.1 to 39.8℃ and respiratory rate was from 42 to 114 times·min-1. There was no significant correlation between rectal temperature and ambient temperature or THI (P>0.05); however, there was a significant linear negtive correlation between rectal temperature and relative humidity (P<0.05, r=0.60). Also, an extremely significant positive correlation was observed between respiratory rate and ambient temperature (P<0.01, r=0.84) or THI (P<0.01, r=0.87); however, no significant correlation was observed between respiratory rate and relative humidity (P>0.05). In summary, the individual physiological condition of sheep can be inferred from ambient temperature, humidity parameters or THI, which can provide data for the prevention of heat stress and diagnosis of related diseases in housed sheep.

Key words: sheep, temperature, relative humidity, temperature-humidity index, respiratory rate, rectal temperature

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