The aim of this study was to evaluate the effects of treating Holstein cows with pegbovigrastim on periparturient diseases, milk production, and reproductive performance while exploring the mode of action of an immunomodulatory protein. Cows were randomly allocated to 1 of 2 treatments, untreated control (CTR, n = 423) and pegbovigrastim (PEG, n = 417). At 7 d from the anticipated calving date (d −7), cows allocated to PEG received a subcutaneous injection of 15 mg of pegylated recombinant bovine granulocyte colony stimulating factor (pegbovigrastim injection, Imrestor, Elanco Animal Health, Greenfield, IN). A second injection was administered within 24 h after calving (d 0). Blood samples were obtained from a subset of cows (CTR, n = 103; PEG, n = 102) at −7 and 0, 3, 7, and 14 d relative to parturition. Samples were used for hemogram and quantification of haptoglobin, nonesterified fatty acids, β-hydroxybutyrate, and trace and macro minerals. Vaginal cytobrush was performed on the same subset cows at d 0, 7, and 14 to assess the relative neutrophil count. Additionally, colostrum samples were collected to measure IgG, IgM, IgA, and lactoferrin concentrations. Postpartum disease occurrence was recorded from calving until 30 d in milk (DIM). Weekly milk yield was recorded for the first 12 wk after calving. Cows treated with PEG had a 3- to 4-fold increase in circulating polymorphonuclear leukocyte, lymphocyte, and monocyte numbers, with a peak at 3 d after treatment followed by a gradual decline, but the counts remained significantly greater compared with CTR at 14 DIM. The administration of PEG did not affect the incidence of clinical and subclinical mastitis, retained fetal membranes, metritis, puerperal metritis, and endometritis. Primiparous cows treated with PEG tended to have lower odds of developing hyperketonemia than CTR [odds ratio (OR) = 0.57, 95% confidence interval (CI) = 0.23 to 1.42]. Cows treated with PEG had higher odds of being diagnosed with lameness within 30 DIM compared with CTR (OR = 1.79, 95% CI = 1.16 to 2.76); however, we found no significant differences by 60 DIM. Treatment with PEG increased the odds of displaced abomasum (OR = 8.27, 95% CI = 1.02 to 66.6). Cows treated with PEG had higher odds of being diagnosed with 1 or more clinical diseases compared with CTR cows (OR = 1.39, 95% CI = 1.02 to 1.90). We observed no differences in linear scores or milk composition between treatments. Furthermore, primiparous cows treated with PEG produced more milk than CTR primiparous cows during the first 12 wk postpartum (PEG = 37.51 ± 0.66; CTR = 35.91 ± 0.65 kg), but no differences were observed on energy-corrected milk. Treatment did not alter reproductive performance; additionally, cows diagnosed with metritis or puerperal metritis and treated with PEG tended to have higher proportion of neutrophils in the vaginal mucosa when compared with CTR metritic cows. Although PEG treatment increased circulating polymorphonuclear leukocyte, monocyte, and lymphocyte numbers, as expected, it was detrimental to cow health because it increased morbidity.

这项研究的目的是评估用培格韦拉司亭治疗荷斯坦奶牛对围产期疾病，产奶量的影响和生殖性能，同时探索免疫调节蛋白的作用方式。将母牛随机分配到2种处理方法之一中，即未经处理的对照（CTR，n = 423）和培高维拉汀（PEG，n = 417）。在预期的产犊日期（d -7）的第7天，分配给PEG的母牛皮下注射15 mg聚乙二醇化重组牛粒细胞集落刺激因子（pegbovigrastim注射，Imrestor，Elanco Animal Health，Greenfield，IN）。产犊后24小时内（d 0）进行第二次注射。相对于分娩，在-7和0、3、7和14 d从一小组母牛（CTR，n = 103； PEG，n = 102）获得血液样本。样品用于血红蛋白和触珠蛋白，非酯化脂肪酸，β-羟基丁酸酯以及微量矿物质和大量矿物质的血常规和定量分析。中性粒细胞计数。另外，收集初乳样品以测量IgG，IgM， IgA和乳铁蛋白浓度。从产犊到牛奶（DIM）30 d记录产后疾病的发生。产犊后的前12周记录每周牛奶产量。用PEG处理的母牛的循环多形核白细胞，淋巴细胞和单核细胞数目增加了3到4倍，在治疗后3 d达到峰值，随后逐渐下降，但与14 DIM时的CTR相比，其计数仍然明显更高。服用PEG不会影响临床和亚临床乳腺炎的发生率，保留的胎膜，子宫炎，产褥期子宫内膜炎和子宫内膜炎。用PEG处理的初乳牛发生高血钾的几率往往比CTR低[几率（OR）= 0.57，95％置信区间（CI）= 0.23至1.42]。与CTR相比，经PEG处理的母牛在30 DIM内被诊断出la足的几率更高（OR = 1.79，95％CI = 1.16至2.76）；但是，我们发现60 DIM并没有显着差异。PEG处理增加了厌恶置换的可能性（OR = 8.27，95％CI = 1.02至66.6）。与CTR奶牛相比，用PEG处理的奶牛被诊断出患有1种或多种临床疾病的几率更高（OR = 1.39，95％CI = 1.02至1.90）。我们观察到线性分数或牛奶成分没有差异治疗之间。此外，在产后前12周内，用PEG处理的初乳牛比CTR初乳牛产生的牛奶更多（PEG = 37.51±0.66； CTR = 35.91±0.65 kg），但经能量校正的牛奶没有观察到差异。治疗没有改变生殖能力；此外，与CTR子宫肥大的母牛相比，被诊断患有子宫炎或产褥期子宫并用PEG治疗的母牛在阴道粘膜中倾向于有更高比例的嗜中性粒细胞。尽管PEG处理可以如预期的那样增加循环多形核白细胞，单核细胞和淋巴细胞的数量，但由于它增加了发病率，因此不利于母牛的健康。