Effects of amount of anechoic intrauterine fluid (IUF) and size of largest follicle at insemination on proportion of cows pregnant as a result of AI (P/AI percentage), as well as factors associated with amount of IUF and size of the follicle were investigated. Follicle size was determined, and amount of IUF in the largest uterine segment was categorized as containing no fluid, ≤10, >10 to 20, and >20 mm using the ultrasonic monitor grid in 735 cows at time of insemination. Multivariable regression models were constructed to evaluate effects of different variables on P/AI percentage, and variables associated with the IUF score and follicle size. On day 30 post-insemination, the P/AI percentage was greater in cows that had >10 to 20 mm IUF than cows with no IUF (OR = 1.9, P = 0.01), but on day 70 post-insemination, the P/AI percentage was similar in cows with different amounts of IUF. Follicle size was not associated with P/AI percentage on days 30 and 70 post-insemination. Cows in spontaneous estrus, multiparous cows, cows with a cystic structure and a typically functional follicle, and Holstein cows had a greater likelihood for a larger IUF value. Primiparous cows, cows on which there was imposing of a hormonal-ovulation-synchronization regimen, and crossbred cows were more likely to have smaller follicles. In conclusion, amount of IUF at the time of insemination and size of the follicle were not associated with P/AI percentage, and several variables were associated with amount of IUF or follicle size.

研究了无回声宫内液 (IUF) 量和授精时最大卵泡大小对人工授精母牛比例（P/AI 百分比）的影响，以及与 IUF 量和卵泡大小相关的因素. 确定卵泡大小，并使用超声监测网格在 735 头奶牛授精时将最大子宫段中的 IUF 量分类为不含液体、≤10、>10 至 20 和 >20 毫米。构建多变量回归模型来评估不同变量对 P/AI 百分比的影响，以及与 IUF 评分和卵泡大小相关的变量。在授精后第 30 天，具有 >10 至 20 mm IUF 的奶牛的 P/AI 百分比高于没有 IUF 的奶牛（OR = 1.9，P = 0.01)，但在授精后第 70 天，具有不同 IUF 量的奶牛的 P/AI 百分比相似。卵泡大小与授精后第 30 天和第 70 天的 P/AI 百分比无关。自然发情的奶牛、经产奶牛、具有囊性结构和典型功能性卵泡的奶牛以及荷斯坦奶牛更有可能获得更大的 IUF 值。初产奶牛、强加激素-排卵同步方案的奶牛和杂交奶牛更有可能具有较小的卵泡。总之，受精时的 IUF 量和卵泡大小与 P/AI 百分比无关，几个变量与 IUF 量或卵泡大小相关。