The reproductive performance of cattle can be suppressed by heat stress. Reproductive organ temperature, especially ovarian temperature, may affect follicle development and ovulation. The establishment of a technique for long-term measurement of ovarian temperature could prove useful in understanding the mechanisms underlying the temperature-dependent changes in follicular development and subsequent ovulation in cows. Here we report a novel method facilitating long-term and continuous recording of ovarian parenchymal temperature in cows. The method revealed that the ovarian temperature in the luteal phase was constantly maintained lower than the vaginal temperature, and that the diurnal temperature variation in the ovary was significantly greater than that in the vagina, suggesting that the ovaries may require a lower temperature than other organs to maintain their functions. This novel method could be used for the further understanding of ovarian functions during estrous cycles in cows.

中文翻译：

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日本黑牛体内卵巢实质温度长期慢性记录技术的建立

热应激会抑制牛的繁殖性能。生殖器官温度，尤其是卵巢温度，可能会影响卵泡发育和排卵。建立长期测量卵巢温度的技术可能有助于了解奶牛卵泡发育和随后排卵的温度依赖性变化的潜在机制。在这里，我们报告了一种有助于长期和连续记录奶牛卵巢实质温度的新方法。该方法显示，黄体期卵巢温度始终保持低于阴道温度，且卵巢温度昼夜变化明显大于阴道温度，这表明卵巢可能需要比其他器官更低的温度来维持其功能。这种新方法可用于进一步了解奶牛发情周期中的卵巢功能。