Adams G P, Sumar J, Ginther O J
University of Wisconsin, Department of Veterinary Science, Madison 53706.
J Reprod Fertil. 1990 Nov;90(2):535-45. doi: 10.1530/jrf.0.0900535.
The effects of lactational status and reproductive status on patterns of follicle growth and regression were studied in 41 llamas. Animals were examined daily by transrectal ultrasonography for at least 30 days. The presence or absence of a corpus luteum and the diameter of the largest and second largest follicle in each ovary were recorded. Llamas were categorized as lactating (N = 16) or non-lactating (N = 25) and randomly allotted to the following groups (reproductive status): (1) unmated (anovulatory group, N = 14), (2) mated by a vasectomized male (ovulatory non-pregnant group, N = 12), (3) mated by an intact male and confirmed pregnant (pregnant group, N = 15). Ovulation occurred on the 2nd day after mating with a vasectomized or intact male in 26/27 (96%) ovulating llamas. Interval from mating to ovulation (2.0 +/- 0.1 days) and growth rate of the preovulatory follicle (0.8 +/- 0.2 mm/day) were not affected by lactational status or the type of mating (vasectomized vs intact male). Waves of follicular activity were indicated by periodic increases in the number of follicles detected and an associated emergence of a dominant follicle that grew to greater than or equal to 7 mm. There was an inverse relationship (r = -0.2; P = 0.002) between the number of follicles detected and the diameter of the largest follicle. Successive dominant follicles emerged at intervals of 19.8 +/- 0.7 days in unmated and vasectomy-mated llamas and 14.8 +/- 0.6 days in pregnant llamas (P = 0.001). Lactation was associated with an interwave interval that was shortened by 2.5 +/- 0.05 days averaged over all groups (P = 0.03). Maximum diameter of anovulatory dominant follicles ranged from 9 to 16 mm and was greater (P less than 0.05) for non-pregnant llamas (anovulatory group, 12.1 +/- 0.4 mm; ovulatory group, 11.5 +/- 0.2 mm) than for pregnant llamas (9.7 +/- 0.2 mm). In addition, lactation was associated with smaller (P less than 0.05) maximum diameter of dominant follicles averaged over all reproductive statuses (10.4 +/- 0.2 vs 11.7 +/- 0.3 mm). The corpus luteum was maintained for a mean of 10 days after ovulation in non-pregnant llamas and to the end of the observational period in pregnant llamas. The presence (ovulatory non-pregnant group) and persistence (pregnant group) of a corpus luteum was associated with a depression in the number of follicles detected and reduced prominence of dominant follicles (anovulatory group greater than ovulatory non-pregnant group greater than pregnant group).(ABSTRACT TRUNCATED AT 400 WORDS)
在41只美洲驼中研究了泌乳状态和生殖状态对卵泡生长和退化模式的影响。通过经直肠超声检查对动物进行至少30天的每日检查。记录每个卵巢中黄体的有无以及最大和第二大卵泡的直径。美洲驼被分为泌乳组（N = 16）或非泌乳组（N = 25），并随机分配到以下组（生殖状态）：（1）未交配（无排卵组，N = 14），（2）与输精管结扎的雄性交配（有排卵但未怀孕组，N = 12），（3）与正常雄性交配并确认怀孕（怀孕组，N = 15）。在27只排卵的美洲驼中，26只（96%）在与输精管结扎或正常雄性交配后第2天排卵。从交配到排卵的间隔时间（2.0±0.1天）和排卵前卵泡的生长速度（0.8±0.2毫米/天）不受泌乳状态或交配类型（输精管结扎雄性与正常雄性）的影响。卵泡活动波通过检测到的卵泡数量的周期性增加以及相关的优势卵泡的出现来表明，优势卵泡生长至大于或等于7毫米。检测到的卵泡数量与最大卵泡直径之间存在负相关（r = -0.2；P = 0.002）。在未交配和输精管结扎交配的美洲驼中，连续优势卵泡出现的间隔时间为19.8±0.7天，在怀孕的美洲驼中为14.8±0.6天（P = 0.001）。泌乳与所有组平均缩短2.5±0.05天的波间间隔相关（P = 0.03）。无排卵优势卵泡的最大直径范围为9至16毫米，未怀孕的美洲驼（无排卵组，12.1±0.4毫米；有排卵组，11.5±0.2毫米）大于怀孕的美洲驼（9.7±0.2毫米）（P < 0.05）。此外，泌乳与所有生殖状态下优势卵泡的平均最大直径较小相关（P < 0.05）（10.4±0.2对11.7±0.3毫米）。在未怀孕的美洲驼中，黄体在排卵后平均维持10天，在怀孕的美洲驼中维持到观察期结束。黄体的存在（有排卵但未怀孕组）和持续存在（怀孕组）与检测到的卵泡数量减少以及优势卵泡的突出程度降低相关（无排卵组>有排卵但未怀孕组>怀孕组）。（摘要截断于400字）
