Alzina-López A, Farfán-Escalante JC, Valencia-Heredia ER, Yokoyama- Kano J

Language: Spanish
References: 16
Page: 112-121
PDF size: 56.04 Kb.

ABSTRACT

Introduction. This study was carried out to determine the relationship between the environmental temperature and humidity and the physiological variables (rectal temperature and respiratory rate) in crossbreed bovines during the months of July, September and November of 1998. Material and methods. Five farms were studied, two from the coastal zone with climate BS0 and three fron the eastern with local climate AW1 Five animals fron each farm were randomly selected to measure their physiological variables at 6, 10, 14 and 18 hours. Temperature, humidity and black globe temperatures in the sunlight and in the shade were determined hourly from 6 to 18 hours. Results. Results indicate a difference in the environmental thermal conditions in both regions, as well as in the respiratory rate and rectal temperature. The changes in the environmental conditions caused variations in the physiological constants. The microclimatic changes per hour apparently had an effect on the physiological variables of the animals from both regions. A relationship was observed between the environmental conditions per month, hour and the physiological variables. Only the animals raised in the east of the state were above the normal limits in respiratory rate and rectal temperature. Conclusion. These variations suggest that the animal activates the mechanism of respiratory evaporative thermal dissipation to compensate the reduced eficiency of sensible heat loss, this mechanism permits the animal to keep its body temperature within the physiological limits.

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