Cavalieri J, Hepworth G, Parker K I, Wright P J, Macmillan K L
Department of Veterinary Science, The University of Melbourne, 3030, Werribee, Australia.
Anim Reprod Sci. 2003 Apr 15;76(3-4):177-93. doi: 10.1016/s0378-4320(02)00260-9.
Ovarian follicular development and concentrations of gonadotrophin and steroid hormones were studied in non-lactating Holstein cows following administration of progesterone (P(4)) or oestradiol benzoate (ODB) at the start of treatment with an intravaginal progesterone releasing insert (IVP(4)) in a 2 by 2 factorial experiment. Cows were treated at random stages of the oestrous cycle with an IVP(4) device (Day 0) and either no other treatment (n=8), 200 mg of P(4) IM (n=9), 2.0 mg of ODB IM (n=8) or both P(4) and ODB (n=9). Seven days later devices were removed and PGF(2alpha) was administered. Twenty-four hours later 1.0mg of ODB was administered IM. Oestrus was detected in 97.1% and ovulation in 64.7% (effect of treatment, P=0.41) of cows within 96 h of removing inserts. In the cows that ovulated, day of emergence of the ovulatory follicle was delayed (P<0.01) and more precise (P<0.05) in cows treated with ODB compared to the cows treated with P(4). Interval from wave emergence to ovulation and the diameter of the ovulatory follicle was less (P<0.05) in cows treated with ODB compared to cows treated with P(4). Combined treatment with P(4) and ODB at the time of starting treatment with an IVP(4) device did not significantly change the pattern of ovarian follicular development compared to treatment with ODB alone. Concentrations of LH and FSH in plasma were less in cows treated with ODB between Days 0 and 4 (P<0.05) while treatment with P(4) increased concentrations of FSH in plasma between Days 0 and 4 (P<0.05). When anovulatory cows were compared to ovulatory cows, diameters of follicles (P<0.001) and growth rate of follicles (P<0.01) were less in anovulatory cows between Days 7 and 9, while concentrations of FSH in plasma were greater (P<0.01), concentrations of LH similar (P>0.90) and concentrations of oestradiol were less (P=0.01) in the anovulatory cows between Days 4 and 10. Our findings support a hypothesis that ovarian follicular development following administration of P(4) or ODB at the start of treatment with an IVP(4) device differs. Anovulatory oestrus may have been associated with reduced maturity and/or later emergence of ovarian follicles.
在一项2×2析因试验中，对非泌乳期荷斯坦奶牛在使用阴道内释放孕酮装置（IVP₄）开始治疗时给予孕酮（P₄）或苯甲酸雌二醇（ODB）后，卵巢卵泡发育以及促性腺激素和甾体激素浓度进行了研究。在发情周期的随机阶段，用IVP₄装置（第0天）对奶牛进行处理，且不进行其他处理（n = 8）、肌肉注射200 mg P₄（n = 9）、肌肉注射2.0 mg ODB（n = 8）或同时给予P₄和ODB（n = 9）。7天后取出装置并给予前列腺素F₂α（PGF₂α）。24小时后肌肉注射1.0 mg ODB。在取出装置后的96小时内，97.1%的奶牛出现发情，64.7%的奶牛排卵（处理效应，P = 0.41）。在排卵的奶牛中，与用P₄处理的奶牛相比，用ODB处理的奶牛排卵卵泡出现的天数延迟（P < 0.01）且更精确（P < 0.05）。与用P₄处理的奶牛相比，用ODB处理的奶牛从卵泡波出现到排卵的间隔以及排卵卵泡的直径更小（P < 0.05）。与单独用ODB处理相比，在使用IVP₄装置开始治疗时联合使用P₄和ODB并没有显著改变卵巢卵泡发育模式。在第0天至第4天，用ODB处理的奶牛血浆中促黄体生成素（LH）和促卵泡生成素（FSH）的浓度较低（P < 0.05），而用P₄处理在第0天至第4天增加了血浆中FSH的浓度（P < 0.05）。当将不排卵的奶牛与排卵的奶牛进行比较时，在第7天至第9天，不排卵奶牛的卵泡直径（P < 0.001）和卵泡生长速率（P < 0.01）较小，而在第4天至第10天，不排卵奶牛血浆中FSH的浓度较高（P < 0.01），LH浓度相似（P > 0.90），雌二醇浓度较低（P = 0.01）。我们的研究结果支持这样一个假设，即在使用IVP₄装置开始治疗时给予P₄或ODB后，卵巢卵泡发育不同。不排卵发情可能与卵巢卵泡成熟度降低和/或出现较晚有关。
