Research on the computer processing of the biological information in farm animals. (2) Analysis of data on calving and estrous period in cattle.

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Out of the physiological informations of cattle, the body temperature can be the most applicable parameter for predicting the time of calving and detecting the estrus. Hence we focused on the body temperature fluctuations measured by the portable data logger on cattle under the practical farm condition in this series of experiments.1. Temperature changes in estrus: 7 Holstein heifers and 8 estrous phases were used. The lowest body temperature (vaginal temperature) in a day changed clearly in peri-estrus period and results are summarized as follow. (1) The lowest temperature began falling from two or three days before estrus. The range of the drop varied from 0.1 to 0.8 ﾟC. (2) The temperature rose by 0.3 to 0.6 ﾟC in the morning of the estrous day compared with the day before. (3) If the estrus prolonged for two days, in the second day the temperature remained in a higher level. (4) In the post-estrus the temperature fell to the previous levels immediately.2. In the calving trial, 24 Holstein cows were used and the results were as follow. (1) The Body temperature rose between 3 and 1 days before calving and dropped thereafter. (2) Temperature rose more clearly during the night hours. (3) Some relationships between the calving time and body temperature fluctuations were suggested.3. As additional results it was found that the body temperature fluctuations consisted of three components as shown bellow. And the filtering method using the moving average, worked well for this purpose. (1) Circadian rhythm ; lowest in the morning and highest in the evening. (2) Rhythm which correspond with feeding interval ; heat increment after eating. (3) Fluctuations of 3 to 5 hours interval ; caused by lying and standing. The software program for more precise heat detection and calving time prediction are developing according to these results.