McNatty K P, Hudson N, Gibb M, Henderson K M, Lun S, Heath D, Montgomery G W
J Endocrinol. 1984 Aug;102(2):189-98. doi: 10.1677/joe.0.1020189.
The plasma concentrations of LH and prolactin and various parameters of ovarian function were examined in cows on known days of the oestrous cycle during May and June (autumn and winter) and during October (spring). Luteinizing hormone peak frequency and plasma prolactin concentrations were significantly higher in October than during the May-June period (LH, P less than 0.05; prolactin, P less than 0.01). The mean diameters of large healthy follicles (greater than or equal to 8 mm diameter) and the dominant oestrogen-secreting follicles were significantly larger (P less than 0.01 for both follicle types) and each follicle contained more granulosa cells (both P less than 0.01) in May-June than in October. The LH responsiveness of theca interna with respect to androstenedione production and the levels of aromatase activity in granulosa cells did not differ with time of year. The corpora lutea were heavier (P less than 0.05) and secreted more progesterone (P less than 0.01) in May-June than in October. It is concluded that seasonal differences in ovarian activity exist in cows and that these differences are probably the consequence of seasonal differences in gonadotrophin secretion.
在5月和6月（秋冬）以及10月（春季）的发情周期已知天数对奶牛进行检查，检测其促黄体生成素（LH）和催乳素的血浆浓度以及卵巢功能的各项参数。10月的促黄体生成素峰值频率和血浆催乳素浓度显著高于5 - 6月期间（LH，P<0.05；催乳素，P<0.01）。5 - 6月大的健康卵泡（直径大于或等于8毫米）和主要分泌雌激素的卵泡的平均直径显著更大（两种卵泡类型均为P<0.01），且每个卵泡含有的颗粒细胞更多（均为P<0.01），相比10月而言。内膜细胞对雄烯二酮产生的LH反应性以及颗粒细胞中的芳香化酶活性水平在一年中的不同时间并无差异。5 - 6月的黄体比10月更重（P<0.05）且分泌更多孕酮（P<0.01）。得出的结论是，奶牛存在卵巢活动的季节性差异，且这些差异可能是促性腺激素分泌季节性差异的结果。
