Applied Animal Biology, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada V6T 1Z4.
Applied Animal Biology, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada V6T 1Z4; University of Guelph, Ridgetown Campus, Ridgetown, ON, Canada N0P 2C0.
J Dairy Sci. 2023 Jul;106(7):4860-4873. doi: 10.3168/jds.2022-22147. Epub 2023 May 10.
The objective of this study was to evaluate the effects of the use of intravaginal probiotics prepartum on the incidence risk of metritis postpartum and conception risk after first artificial insemination (AI). A total of 606 Holstein cows were enrolled 3 wk before their expected calving date from 2 farms. Cows were randomly assigned to either receive a 2-mL dose of a combination of 3 lactic acid bacteria (probiotic treatment) washed with approximately 2 mL of a sterile saline solution, into the vaginal canal twice weekly until parturition, or no intervention (control). Metritis diagnoses were carried out on 6 and 12 d postpartum. Vaginal discharge and rectal temperature were assessed, and vaginal discharge was scored on a scale from 1 to 4, where 1 = clear and 4 = fetid, purulent discharge. Metritis was defined as cows having a vaginal discharge score of 4 with or without fever (rectal temperature ≥39.5°C) on either 6 or 12 d postpartum, or both. Cows were bred after a 60-d voluntary waiting period primarily via the detection of estrus using automated activity monitors; cows not found in estrus were enrolled onto timed AI protocols to receive first breeding before 100 DIM. Pregnancy diagnosis was carried out at d 35 ± 7 post-AI on both farms. Data were analyzed via ANOVA using linear mixed regression models and survival analysis using a Cox proportional hazard model. Total incidence risk of metritis was 23.7% and 34.4% on farm A and farm B, respectively. Overall, the incidence of metritis was not different between treatment groups (control: 41.6 ± 3.8%; probiotic: 38.6 ± 4.0%); however, an interaction by farm was detected, where the probiotic treatment reduced metritis on one farm but not on the other. Conception risk after first AI was not affected by treatment. However, we detected an interaction between parity and treatment, where multiparous cows receiving the probiotic treatment were more likely to become pregnant compared with multiparous cows within the control group (hazard ratio: 1.33; 95% confidence interval: 1.10-1.60); no effect of probiotic treatment was found on the hazard of pregnancy for primiparous cows. In addition, the probiotic treatment was associated with an increased proportion of cows being detected in estrus for the first AI postpartum. In conclusion, vaginal probiotic treatment applied during the 3 wk prepartum was associated with a decreased incidence of metritis on one farm but not the other, suggesting that farm management may be a key player influencing treatment efficacy. Overall, probiotic treatment was found to have only limited effects on fertility in the current study.
本研究旨在评估产前阴道使用益生菌对产后子宫内膜炎发病风险和首次人工授精（AI）后妊娠风险的影响。从两个牧场选择了 606 头荷斯坦奶牛，在预计分娩前 3 周入组。奶牛被随机分配接受 2 毫升剂量的 3 种乳酸菌（益生菌治疗），用约 2 毫升无菌生理盐水冲洗，每周两次直到分娩，或不干预（对照组）。产后第 6 天和第 12 天进行子宫内膜炎诊断。评估阴道分泌物和直肠温度，并对阴道分泌物进行评分，范围从 1 到 4，其中 1 = 清亮，4 = 恶臭、脓性分泌物。子宫内膜炎定义为奶牛在产后第 6 天或第 12 天或两者都出现阴道分泌物评分 4 分，伴有或不伴有发热（直肠温度≥39.5°C）。奶牛在 60 天自愿等待期后主要通过自动活动监测器检测发情进行配种；未发现发情的奶牛将被纳入定时 AI 方案，在 100 天内进行首次配种。在两个牧场，产后第 35 天±7 天进行妊娠诊断。数据采用方差分析线性混合回归模型和 Cox 比例风险模型生存分析进行分析。农场 A 和农场 B 的子宫内膜炎总发病率分别为 23.7%和 34.4%。总体而言，治疗组之间子宫内膜炎的发病率没有差异（对照组：41.6±3.8%；益生菌组：38.6±4.0%）；然而，检测到了一个由农场引起的交互作用，即在一个农场中，益生菌治疗降低了子宫内膜炎的发病率，但在另一个农场中没有。首次 AI 后的妊娠风险不受治疗影响。然而，我们检测到产次和治疗之间存在交互作用，接受益生菌治疗的经产奶牛比对照组中的经产奶牛更有可能怀孕（风险比：1.33；95%置信区间：1.10-1.60）；未发现益生菌治疗对初产奶牛妊娠风险的影响。此外，益生菌治疗与产后首次 AI 时发情奶牛的比例增加有关。总之，产前 3 周阴道应用益生菌治疗与一个农场而非另一个农场的子宫内膜炎发病率降低有关，这表明农场管理可能是影响治疗效果的关键因素。总的来说，在本研究中，益生菌治疗对生育力的影响有限。
