Munro R K
Department of Physiology, University of New England, Armidale, New South Wales.
Aust Vet J. 1990 Sep;67(9):313-5. doi: 10.1111/j.1751-0813.1990.tb07811.x.
Twelve suckling and 12 non-lactating post-partum cows were treated with a progesterone-releasing pessary for 7 or 14 d followed by an injection of 500 micrograms oestradiol benzoate (ODB) 24 h after pessary removal or no injection. Suckling had no significant effect on plasma progesterone concentrations (plasma P4) or plasma luteinising hormone concentrations (plasma LH) during pessary insertion. After pessary removal plasma LH rose in response to ODB. The extent of the rise was similar in suckling and non-lactating cows treated with progesterone for 14 d but was significantly lower in non-lactating than suckling cows (P less than 0.025) treated for 7 d. These findings indicate that suckling increases the responsiveness of plasma LH in post-partum cows following progesterone and oestrogen treatment compared to non-lactating cows and that extended treatment with progesterone can remove this difference.
12头哺乳期和12头非哺乳期的产后母牛接受了释放孕酮的子宫托治疗，为期7天或14天，在取出子宫托24小时后注射500微克苯甲酸雌二醇（ODB），或者不进行注射。在放置子宫托期间，哺乳对血浆孕酮浓度（血浆P4）或血浆促黄体生成素浓度（血浆LH）没有显著影响。取出子宫托后，血浆LH因ODB而升高。在用孕酮治疗14天的哺乳期和非哺乳期母牛中，升高的程度相似，但在接受7天治疗的非哺乳期母牛中，升高程度显著低于哺乳期母牛（P<0.025）。这些发现表明，与非哺乳期母牛相比，哺乳会增加产后母牛在接受孕酮和雌激素治疗后血浆LH的反应性，并且延长孕酮治疗可以消除这种差异。
