产前血液生化和免疫变量对奶牛产后乳腺炎风险的预测潜力。
Prognostic potential of pre-partum blood biochemical and immune variables for postpartum mastitis risk in dairy cows.
机构信息
Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, P. R. China.
出版信息
BMC Vet Res. 2020 May 14;16(1):136. doi: 10.1186/s12917-020-02314-6.
BACKGROUND
Mastitis is the most frequent diseases for transition cows. Identification of potential biomarkers for diagnosis of mastitis is important for its prevention. Thus, this study was conducted to investigate blood variables related to lipid metabolism, oxidative stress and inflammation, and serum variables that are related to health in postpartum cows.
RESULTS
Seventy-six healthy Holstein dairy cows at week 4 before calving were selected to collect blood samples from weeks - 4 to 4 weekly relative to calving, respectively. Milk yield and composition were recorded weekly. According to the cut-off of somatic cell counts (SCC) for diagnosis of mastitis, 33 cows with SCC ≥ 500,000 cells ml, 20 cows with 200,000 cells ≤ SCC < 500,000 cells ml, and 23 cows with SCC < 200,000 cells ml were defined as high, middle, and low SCC, respectively. Serum concentrations of β-hydroxybutyrate were higher (P < 0.01) during all weeks, and non-esterified fatty acids were higher in high SCC than in low SCC cows from weeks - 3 to 2 relative to calving. Higher serum concentrations of superoxide dismutase (P < 0.01) and lower malondialdehyde levels (P < 0.01) in low SCC than in high SCC cows indicate that the latter suffered from oxidative stress. The difference analysis of the three groups suggested that none of the above-mentioned variables can be used as potential prognostic candidates. On the other hand, high SCC cows exhibited higher blood neutrophil to lymphocyte ratio (NLR, P < 0.01) and platelet to lymphocyte ratio (PLR, P < 0.01) than low SCC cows, with a higher NLR (P < 0.01) in middle SCC than in low SCC cows. The high SCC cows had lower levels of anti-inflammatory factors including IL-10 (P = 0.05), but higher levels of proinflammatory factors such as IL-6 (P < 0.01), TNF-α (P < 0.05), and PSGL-1 (P < 0.01) than low SCC cows.
CONCLUSIONS
The significantly different NLR and PLR pre-partum between the middle and low SCC cows suggest their prognostic potential for postpartum mastitis risk.
背景
乳腺炎是围产期奶牛最常见的疾病。鉴定用于乳腺炎诊断的潜在生物标志物对于乳腺炎的预防非常重要。因此，本研究旨在探讨与产后奶牛健康相关的血脂代谢、氧化应激和炎症相关的血液变量和血清变量。
结果
选择 76 头健康荷斯坦奶牛，在分娩前第 4 周分别采集每周-4 至 4 周与分娩相关的血液样本。每周记录牛奶产量和成分。根据体细胞计数（SCC）用于乳腺炎诊断的截止值，将 SCC≥500,000 个细胞/ml 的 33 头奶牛、200,000 个细胞≤SCC<500,000 个细胞/ml 的 20 头奶牛和 SCC<200,000 个细胞/ml 的 23 头奶牛分别定义为高 SCC、中 SCC 和低 SCC。β-羟丁酸的血清浓度在所有周均较高（P<0.01），与分娩相关的前 3 周至 2 周，高 SCC 奶牛的非酯化脂肪酸高于低 SCC 奶牛。低 SCC 奶牛的超氧化物歧化酶血清浓度较高（P<0.01），丙二醛水平较低（P<0.01），表明后者遭受氧化应激。三组间差异分析表明，上述变量均不能作为潜在的预后候选物。另一方面，高 SCC 奶牛的血液中性粒细胞与淋巴细胞比值（NLR，P<0.01）和血小板与淋巴细胞比值（PLR，P<0.01）高于低 SCC 奶牛，中 SCC 奶牛的 NLR 高于低 SCC 奶牛（P<0.01）。高 SCC 奶牛的抗炎因子如 IL-10 水平较低（P=0.05），但促炎因子如 IL-6（P<0.01）、TNF-α（P<0.05）和 PSGL-1（P<0.01）水平较高。
结论
中 SCC 和低 SCC 奶牛之间产前 NLR 和 PLR 的显著差异提示其对产后乳腺炎风险的预后潜力。
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