Kyle B L, Kennedy A D, Small J A
Department of Animal Science, University of Manitoba, Winnipeg, Canada.
Theriogenology. 1998 Jun;49(8):1437-49. doi: 10.1016/s0093-691x(98)00090-9.
Peaks in vaginal temperature were assessed as predictors of estrus in 22 suckled beef cows during 2 breeding seasons. A flexible plastic anchor was used to retain a temperature radiotransmitter within the cow vagina and vaginal temperature was monitored at 4-min intervals. Blood was collected twice weekly for analysis of serum progesterone to confirm the occurrence of estrus and ovarian status was checked weekly using transrectal ultrasonography. Visual observations of estrous behavior were made for 20 min/h between 0400 and 0800 h and casually from 0800 to 1600 h (4 to 6 times). Values for vaginal temperature were available for 47 estrous periods. The prediction of estrus based on vaginal temperature was excellent when an estral peak in vaginal temperature was defined as an increase of at least 0.4 degree C for 3 or more consecutive hours using the corresponding hourly means of a 2 or 3-d baseline. Combining the results of 2 separate years and using a 3-d baseline, a peak in vaginal temperature was found for 42 of 47 confirmed estrus periods (detection sensitivity of 89.4% and prediction power positive of 85.7%). Corresponding detection sensitivity and prediction power positive for visual observations of standing estrus were 53.2 and 96.2%, respectively. The mean maximal increase in vaginal temperature at estrus was 0.9 +/- 0.3 degree C and the mean duration of the estrual peak in vaginal temperature was 6.5 +/- 2.7 h. In addition, vaginal temperature was found to be significantly depressed for 3 d prior to estrus and significantly elevated at mid-cycle.
在两个繁殖季节中，对22头哺乳肉用母牛的阴道温度峰值进行了评估，以预测发情情况。使用一个柔性塑料锚将温度无线电发射器固定在母牛阴道内，每隔4分钟监测一次阴道温度。每周采集两次血液，分析血清孕酮以确认发情的发生，并每周使用经直肠超声检查卵巢状态。在04:00至08:00之间每小时进行20分钟的发情行为视觉观察，并在08:00至16:00之间不定期观察（4至6次）。获得了47个发情期的阴道温度值。当将阴道温度的发情峰值定义为使用2或3天基线的相应每小时平均值连续3小时或更长时间至少升高0.4摄氏度时，基于阴道温度对发情的预测效果极佳。结合两个单独年份的结果并使用3天基线，在47个确认的发情期中，有42个出现了阴道温度峰值（检测灵敏度为89.4%，阳性预测能力为85.7%）。站立发情视觉观察的相应检测灵敏度和阳性预测能力分别为53.2%和96.2%。发情时阴道温度的平均最大升高为0.9±0.3摄氏度，阴道温度发情峰值的平均持续时间为6.5±2.7小时。此外，发现发情前3天阴道温度显著降低，在发情周期中期显著升高。
