Eldon J, Olafsson T
Acta Vet Scand. 1986;27(3):421-39. doi: 10.1186/BF03548156.
The paper describes the postpartum (pp) reproductive performance of 252 dairy cows in 2 areas in Iceland, in the north (Eyjafjörður) and in the south (Skeið), during a 12 months period. First pp ovulation occurred significantly earlier in primiparous cows, in cows in Skeið and in cows that calved in September—November. The average time of first pp artificial insemination (ai) was 72 days in both areas. Conception rate to first ai in these cows was 58 % in Eyjafjörður and 53 % in Skeið and the number of ai per conception was 1.6 and 1.8, respectively. In Eyjafjörður, 23 % of the cows were inseminated at the time of first pp ovulation. Sixtytwo percent of these cows conceived. In Skeið, 20 cows were inseminated at the time of first pp ovulation, and 9 or 45 % of these cows conceived. The interval from calving to conception was, on the average, 92 days in Eyjafjörður and 100 days in Skeið. Comparison of results from individual farms showed increase in number of conceptions to first pp ai (35–72 %) and decrease in number of services per conception (2.0–1.3) with increased mean number of days from calving to first ai (62–82 days).
该论文描述了冰岛北部（埃亚菲亚德拉冰盖）和南部（斯基德）两个地区252头奶牛在12个月期间的产后繁殖性能。初产奶牛、斯基德地区的奶牛以及9月至11月产犊的奶牛首次产后排卵明显更早。两个地区首次产后人工授精的平均时间均为72天。这些奶牛首次人工授精的受孕率在埃亚菲亚德拉冰盖为58%，在斯基德为53%，每次受孕的人工授精次数分别为1.6次和1.8次。在埃亚菲亚德拉冰盖，23%的奶牛在首次产后排卵时进行了人工授精。其中62%的奶牛受孕。在斯基德，20头奶牛在首次产后排卵时进行了人工授精，其中9头或45%的奶牛受孕。从产犊到受孕的间隔时间，在埃亚菲亚德拉冰盖平均为92天，在斯基德为100天。各农场结果的比较显示，随着从产犊到首次人工授精的平均天数增加（62 - 82天），首次产后人工授精的受孕数增加（35% - 72%），每次受孕的输精次数减少（2.0 - 1.3次）。
