Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
J Dairy Sci. 2010 May;93(5):1979-86. doi: 10.3168/jds.2009-2626.
Favorable uterine involution and ovarian activity are very important for the next reproductive cycle of postpartum cows. The objective of this study was to evaluate the effect of parity on uterine involution and resumption of ovarian activity in Chinese Holstein dairy cows after calving under similar postpartum nutritional conditions. Traits of the status of uterus and ovaries detected by ultrasonography, dry matter intake (DMI), milk yield, body condition score (BCS), and estradiol concentration in milk samples were analyzed for 46 Chinese Holstein dairy cows in various parities (primiparous=18; biparous=13; multiparous=15). The results showed that there was no significant difference for DMI, BCS, and milk yield among different parities; all cows were considered to be under similar nutritional conditions. Days of the previous gravid uterine horn involution were significantly greater in primiparous dairy cows than in biparous and multiparous dairy cows. Days from calving to ovulation (first and second) and the number of follicular waves to first ovulation were significantly greater in primiparous cows than in multiparous cows. In summary, there was a significant negative relationship between parity and postpartum uterine involution and resumption of ovarian activity in Chinese Holstein cows under similar body conditions.
产后子宫收缩和卵巢活动的良好状态对奶牛下一个繁殖周期非常重要。本研究旨在评估在相似产后营养条件下，不同胎次对产后中国荷斯坦奶牛子宫复旧和卵巢活动恢复的影响。对 46 头中国荷斯坦奶牛的超声检测的子宫和卵巢状态特征、干物质采食量（DMI）、产奶量、体况评分（BCS）和奶样中雌二醇浓度进行了分析，这些奶牛的胎次分别为（初产=18 头；经产=13 头；多产=15 头）。结果表明，不同胎次间的 DMI、BCS 和产奶量无显著差异；所有奶牛均被认为处于相似的营养条件下。初产奶牛上次妊娠子宫角的退化天数明显长于经产和多产奶牛。从产犊到排卵（第一次和第二次）以及到第一次排卵的卵泡波数天数，初产奶牛明显多于多产奶牛。总之，在相似体况下，中国荷斯坦奶牛的胎次与产后子宫复旧和卵巢活动恢复呈显著负相关。
