Vailes L D, Washburn S P, Britt J H
Department of Animal Science, North Carolina State University, Raleigh 27695-7621.
J Anim Sci. 1992 Jul;70(7):2094-103. doi: 10.2527/1992.7072094x.
Two experiments were conducted to determine how steroid milieus and pregnancy affect sexual behavior. Experiment 1 was arranged as a Latin square with five ovariectomized cows and five steroid milieus: no steroid (N); progesterone (P4); estradiol benzoate (EB); P4 + EB; and P4 followed by EB (P4:EB). Progesterone was administered via pessary (2 g of P4) for 5 d and EB was injected (1 mg i.m.) on the day before a test day. On a test day, cows were exposed for four 30-min periods, twice each with a tied or a loose estrual test cow (prepared using P4:EB). Sexual behaviors recorded were attempted mounts, successful mounts, front mounts, stands, head butts, chin rests, and vulvar sniffs. Cows exhibited more (P less than .05) sexual behavior during periods with the loose estrual test cow than with the tied estrual test cow. Cows receiving P4 alone ranked lowest among treatments for each behavior, whereas cows receiving EB or P4:EB ranked highest or second-highest. Progesterone prevented stands in cows given P4 + EB, but these cows displayed mounting behaviors similar to those of cows given EB and P4:EB. Cows given P4 + EB were similar to those given N for most behaviors. In Exp. 2, 118 intact, lactating cows were observed in groups of four or five for mounting of estrual test cows during 24, 30-min observation periods on 8 d over 2 yr. The design was an incomplete block with physiological state, parity, estradiol, progesterone, and a calculated estrogen:progesterone ratio included in the model. Each block included one or two cows at 23 +/- .8 d after insemination, divided retrospectively into one pregnant and two non-pregnant groups (low [less than 1 ng/mL] vs high progesterone), and other cows at 89 +/- 1.0, 152 +/- 1.2, and 234 +/- 1.7 d of gestation (six physiological groups). Most cows were observed once, but 27 cows were included twice during 2 yr. Only 60% of the 118 cows made attempted or successful mounts even though estrual test cows were always receptive. Physiological state was not associated with amount of mounting because very active (greater than or equal to five attempts) and inactive cows were represented in all physiological groups. The estrogen:progesterone ratio on test day accounted for small, but significant, variation in mounting behavior. For cows observed on two different days, correlations between successive observations were .46 for attempted mounts, .78 for successful mounts, and .71 for total mounts.(ABSTRACT TRUNCATED AT 400 WORDS)
进行了两项实验，以确定类固醇环境和怀孕如何影响性行为。实验1采用拉丁方设计，有五头去卵巢母牛和五种类固醇环境：无类固醇（N）；孕酮（P4）；苯甲酸雌二醇（EB）；P4 + EB；以及先给予P4后给予EB（P4:EB）。通过子宫托给予孕酮（2克P4），持续5天，并在测试日前一天注射EB（1毫克，肌肉注射）。在测试日，让母牛与一头发情测试母牛接触四个30分钟时段，该测试母牛分别用绳子拴住或放开（采用P4:EB处理）进行两次接触。记录的性行为包括尝试爬跨、成功爬跨、前爬跨、站立、头部顶撞、下巴倚靠和外阴嗅闻。与拴住的发情测试母牛接触期间相比，母牛在与放开的发情测试母牛接触期间表现出更多（P小于0.05）的性行为。单独接受P4处理的母牛在每种行为的处理组中排名最低，而接受EB或P4:EB处理的母牛排名最高或第二高。孕酮阻止了给予P4 + EB处理的母牛站立，但这些母牛表现出的爬跨行为与给予EB和P4:EB处理的母牛相似。给予P4 + EB处理的母牛在大多数行为上与给予N处理的母牛相似。在实验2中，在两年内的8天里，每次24个30分钟观察时段，将118头未阉割的泌乳母牛分成四五头一组，观察它们对发情测试母牛的爬跨情况。该设计是一个不完全区组设计，模型中纳入了生理状态、胎次、雌二醇、孕酮以及计算得出的雌激素：孕酮比值。每个区组包括授精后23±0.8天的一两头母牛，回顾性地分为一个怀孕组和两个未怀孕组（孕酮水平低[小于1纳克/毫升]与高孕酮组），以及妊娠89±1.0天、152±1.2天和234±1.7天的其他母牛（六个生理组）。大多数母牛只被观察一次，但在两年内有27头母牛被观察了两次。尽管发情测试母牛总是处于接受状态，但118头母牛中只有60%进行了尝试或成功爬跨。生理状态与爬跨次数无关，因为在所有生理组中都有非常活跃（大于或等于五次尝试）和不活跃的母牛。测试日的雌激素：孕酮比值在爬跨行为中占了小但显著的变异。对于在两个不同日期观察的母牛，连续观察之间的相关性，尝试爬跨为0.46，成功爬跨为0.78，总爬跨次数为0.71。（摘要截于400字）
