Kendrick K M, Keverne E B
A.F.R.C. Institute of Animal Physiology and Genetics Research, Babraham, Cambridge.
Physiol Behav. 1991 Apr;49(4):745-50. doi: 10.1016/0031-9384(91)90313-d.
The effects of treating ovariectomised nulliparous and multiparous ewes with progesterone and estrogen on maternal behavior with or without vagino-cervical stimulation were investigated. Following 48 h of estrogen treatment there was neither evidence for stimulation of maternal behavior, nor a reduction in aggressive behavior, towards lambs by either multiparous or nulliparous ewes compared with control treatment (injections of the oil vehicle). Following 5 min of mechanical vaginocervical stimulation, the multiparous estrogen-treated ewes showed both positive maternal responses (low pitch bleats, licking, sniffing and approaching the lamb) and a reduction in aggression (butts) and negative behavior (withdrawal from the lamb) towards the lambs, whereas the nulliparous ewes showed only a reduction in aggression and negative behavior. Neither group showed positive maternal responses following vaginocervical stimulation without steroid priming. When the ewes received two weeks of progesterone priming prior to estrogen treatment, both multiparous and nulliparous ewes showed reduced aggression towards, and withdrawal from, the lambs compared to the control condition, but no positive maternal responses apart from an increased sniffing of the lamb. After vaginocervical stimulation positive maternal responses showed by multiparous ewes were significantly potentiated compared to those shown following estrogen treatment alone. Nulliparous ewes remained unresponsive on positive maternal behaviors. These studies show that hormonal priming has little effect in inducing the onset of maternal behavior in multiparous or nulliparous sheep but is an essential prerequisite for vaginocervical stimulation to do so in multiparous animals.
研究了用孕酮和雌激素处理去卵巢未生育和经产母羊对有或无阴道-宫颈刺激时母性行为的影响。与对照处理（注射油载体）相比，雌激素处理48小时后，未生育和经产母羊对羔羊既没有表现出母性行为受到刺激的迹象，也没有表现出攻击行为减少。在机械性阴道-宫颈刺激5分钟后，经雌激素处理的经产母羊对羔羊表现出积极的母性行为反应（低音调咩叫、舔舐、嗅闻和接近羔羊），同时攻击行为（顶撞）和消极行为（躲避羔羊）减少，而未生育母羊仅表现出攻击行为和消极行为减少。在没有类固醇预处理的情况下，两组母羊在阴道-宫颈刺激后均未表现出积极的母性行为反应。当母羊在雌激素处理前接受两周的孕酮预处理时，与对照情况相比，经产和未生育母羊对羔羊的攻击行为和躲避行为均减少，但除了对羔羊嗅闻增加外，没有积极的母性行为反应。与仅接受雌激素处理相比，经产母羊在阴道-宫颈刺激后表现出的积极母性行为反应明显增强。未生育母羊对积极的母性行为仍无反应。这些研究表明，激素预处理对诱导经产或未生育绵羊的母性行为起始作用不大，但对于经产动物而言，是阴道-宫颈刺激诱导母性行为的必要前提条件。
