Eldon J, Olafsson T
Acta Vet Scand. 1988;29(3-4):385-92. doi: 10.1186/BF03548633.
The time of ovulation, artificial insemination (AI), conception and conception rate were studied in 412 Icelandic dairy cows from 2 different areas during a period of 3 years. To assess these parameters the progesterone level was measured in sequential samples of milk and the status of the genital organs evaluated by monthly rectal palpations. The time and number of AI was recorded and the conception rate calculated and compared with the other parameters. Furthermore, the length of the calving interval and gestation period were determined. The effects of year, season, area, age, herd and parity on these parameters were evaluated. The overall mean for the time of first post partum ovulation was 42 days and varied from 29 to 49 days between herds. This is a considerably longer time than recorded for many other breeds of dairy cows. The effects of season, area and herd were significant for the time of first post partum ovulation. The overall time of first post partum AI and conception were 74 days and 97 days, respectively. In spite of late onset of ovarian activity in Icelandic dairy cows, these two pararmeters are comparable to those of other breeds of cattle. The effects of season, parity and herd were significant for these two parameters. The conception rate to first post partum AI was 59% and the number of AI per conception was 1.6. The time of conception correlated closely (r = 0.5) with the time of first post partum AI, but the conception rate to first AI increased and the number of AI per conception decreased with increasing time of first post partum AI. The calving interval was 382 days and the gestation period was 287 days.
在3年时间里，对来自2个不同地区的412头冰岛奶牛的排卵时间、人工授精（AI）时间、受孕情况及受孕率进行了研究。为评估这些参数，对连续采集的牛奶样本测量孕酮水平，并通过每月直肠触诊评估生殖器官状况。记录人工授精的时间和次数，计算受孕率并与其他参数进行比较。此外，还确定了产犊间隔和妊娠期的长度。评估了年份、季节、地区、年龄、牛群和胎次对这些参数的影响。产后首次排卵时间的总体平均值为42天，不同牛群之间在29至49天之间变化。这比许多其他品种的奶牛记录的时间长得多。季节、地区和牛群对产后首次排卵时间有显著影响。产后首次人工授精和受孕的总体时间分别为74天和97天。尽管冰岛奶牛卵巢活动开始较晚，但这两个参数与其他品种的牛相当。季节、胎次和牛群对这两个参数有显著影响。产后首次人工授精的受孕率为59%，每次受孕的人工授精次数为1.6次。受孕时间与产后首次人工授精时间密切相关（r = 0.5），但随着产后首次人工授精时间的增加，首次人工授精的受孕率增加，每次受孕的人工授精次数减少。产犊间隔为382天，妊娠期为287天。
