Zulu Victor Chisha, Sawamukai Yutaka, Nakada Ken, Kida Katsuya, Moriyoshi Masaharu
Department of Obstetrics and Gynecology, Graduate School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan.
J Vet Med Sci. 2002 Oct;64(10):879-85. doi: 10.1292/jvms.64.879.
The relationship among nutritional status, systemic insulin-like growth factor-I (IGF-I) and ovarian function early postpartum were investigated. A total of 27 Holstein-Friesian cows, 10 that cycled normally within 20 days postpartum, 5 diagnosed with follicular cysts, 8 with persistent corpus luteum (CL) after the first ovulation postpartum and 4 with inactive ovaries were used for the study. Blood samples were collected 1-3 times per week, for 60 days pre- and postpartum, for IGF-I, progesterone, estradiol, free fatty acids (FFA), blood urea nitrogen (BUN), and aspartate aminotransferase (AST) determination. Inactive ovary and cystic cows had a higher body condition score before calving and lost more condition than normal or persistent CL cows. Immediately postpartum, IGF-I levels were higher and rose sharply in cows that cycled normally than in cystic, inactive ovary or persistent CL cows. At calving and early postpartum, FFA was higher in inactive ovary and cystic than in normal and persistent CL cows. There was a significant strong positive relationship between IGF-I and BUN, and strong negative relationships between IGF-I and FFA and AST in all groups. There was a positive relationship between serum IGF-I and estradiol in normal cystic and inactive ovary cows. This study found that overconditioned cows during the dry period or at calving, lost more body condition postpartum. These cows also had a deeper and longer period of negative energy balance (NEB), poor liver function and low circulating IGF-I concentrations early postpartum. Such cows were likely to have poor reproductive function as seen in development of cystic ovaries, persistent CL and inactive ovary. Changes in serum IGF-I early postpartum may help predict both nutritional and reproductive status in dairy cattle.
研究了产后早期营养状况、全身胰岛素样生长因子-I（IGF-I）与卵巢功能之间的关系。本研究共使用了27头荷斯坦-弗里生奶牛，其中10头在产后20天内正常发情，5头被诊断为卵泡囊肿，8头在产后首次排卵后出现黄体持久化（CL），4头卵巢无活性。在产前和产后60天内，每周采集1 - 3次血样，用于测定IGF-I、孕酮、雌二醇、游离脂肪酸（FFA）、血尿素氮（BUN）和天冬氨酸转氨酶（AST）。卵巢无活性和患有囊肿的奶牛在产犊前体况评分较高，且比正常或黄体持久化的奶牛体况损失更多。产后立即测定，正常发情奶牛的IGF-I水平较高且急剧上升，高于患有囊肿、卵巢无活性或黄体持久化的奶牛。在产犊时和产后早期，卵巢无活性和患有囊肿的奶牛的FFA高于正常和黄体持久化的奶牛。在所有组中，IGF-I与BUN之间存在显著的强正相关，IGF-I与FFA和AST之间存在强负相关。在正常、患有囊肿和卵巢无活性的奶牛中，血清IGF-I与雌二醇之间存在正相关。本研究发现，干奶期或产犊时体况过肥的奶牛，产后体况损失更多。这些奶牛产后负能量平衡（NEB）的程度更深、持续时间更长，肝功能较差，产后早期循环IGF-I浓度较低。如卵泡囊肿、黄体持久化和卵巢无活性的发生所示，这类奶牛可能生殖功能较差。产后早期血清IGF-I的变化可能有助于预测奶牛的营养和生殖状况。
