Laboratory of Theriogenology, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan.
J Reprod Dev. 2021 Oct 29;67(5):291-299. doi: 10.1262/jrd.2021-052. Epub 2021 Sep 11.
A certain level of endometrial bacterial infection and inflammation is involved in bovine uterine involution during the puerperal period. Factors that hamper normal uterine involution expose the uterine environment to pathological conditions, causing different endometritis levels. The lack of proper diagnostic tools extends the time to conception. Efforts have been made to elucidate the postpartum uterine environment, including bacterial flora, changes in transient endometrial inflammation, and the pathophysiology of endometritis, to improve bovine reproductive performance. E. coli and Trueperella pyogenes in the uterus are likely to cause persistent infection, and Mycoplasma bovigenitalium infection is associated with dystocia and cytological endometritis in postpartum dairy cows. Due to the widespread use of cytobrush as a diagnostic tool for bovine subclinical endometritis (SE) that enables quantification of the degree of inflammation, we found that endometritis at week 5 postpartum was associated with delayed first ovulation. Approximately 30% of open cows have SE during the postpartum period, and cows with low blood glucose during prepartum have a high risk of developing SE. Additionally, cows with purulent vaginal discharge do not always have endometritis but only vaginitis and/or cervicitis. Intrauterine infusion of polyvinylpyrrolidone-iodine (PVP-I) improves fertility and promotes endometrial epithelial cell regeneration after inducing transient uterine inflammation, suggesting that PVP-I could be a good alternative to antibiotics. In conclusion, prepartum management to prevent glucose deficiency, prompt diagnosis to identify causative agents and intrauterine inflammation levels, and appropriate treatment to minimize antimicrobial resistance is beneficial for tackling endometritis and improving reproductive performance in bovine herds.
在产后期间，牛的子宫复旧过程中涉及一定程度的子宫内膜细菌感染和炎症。阻碍正常子宫复旧的因素使子宫环境处于病理状态，导致不同程度的子宫内膜炎。缺乏适当的诊断工具会延长受孕时间。人们一直在努力阐明产后子宫环境，包括细菌菌群、短暂子宫内膜炎症的变化以及子宫内膜炎的病理生理学，以提高牛的繁殖性能。大肠杆菌和腐生真杆菌可能在子宫内引起持续感染，而牛支原体感染与产后奶牛的难产和细胞学子宫内膜炎有关。由于广泛使用细胞刷作为牛亚临床子宫内膜炎（SE）的诊断工具，可以定量炎症程度，我们发现产后第 5 周的子宫内膜炎与首次排卵延迟有关。大约 30%的开放奶牛在产后期间患有 SE，产前血糖低的奶牛患 SE 的风险较高。此外，有脓性阴道分泌物的奶牛并不总是患有子宫内膜炎，而只是患有阴道炎和/或宫颈炎。聚维酮碘（PVP-I）宫内灌注可改善牛的繁殖力，并在诱导短暂子宫炎症后促进子宫内膜上皮细胞再生，这表明 PVP-I 可能是抗生素的良好替代品。总之，产前管理以预防低血糖、及时诊断以确定病原体和子宫内炎症水平以及适当的治疗以最大程度减少抗生素耐药性，有利于解决子宫内膜炎并提高牛群的繁殖性能。
