Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Jilin, 130062, Changchun, China.
Mammalian NutriPhysioGenomics, Department of Animal Sciences, Division of Nutritional Sciences, University of Illinois, 61801, Urbana, USA.
BMC Vet Res. 2020 Dec 2;16(1):470. doi: 10.1186/s12917-020-02676-x.
Left displaced abomasum (LDA) occurs at high frequency in the early postpartum period and can affect production performance of dairy cows. Clinical diagnosis of LDA is usually done by abdominal auscultation and percussion. The purpose of this study was to explore the potential applicability of blood biomarkers for early warning and diagnosis of LDA in dairy cows.
Twenty early postpartum healthy cows and thirty early postpartum LDA cows of similar parity were used. A receiver operating characteristic curve (ROC) method was used to analyze the sensitivity of hematological biomarkers to LDA including energy balance metabolic biomarkers, liver/kidney function biomarkers, and minerals. A cut-off point was defined for each of the selected hematological biomarkers deemed sensitive markers of LDA. Compared with healthy cows, body condition score (BCS), dry matter intake (DMI) and milk production were lower in LDA cows. Among energy metabolism markers, serum non-esterified fatty acid (NEFA), β-hydroxybutyric acid (BHBA), insulin (INS), and revised quantitative insulin sensitivity check index (RQUICKI) levels were lower while serum glucagon (GC) was greater in LDA cows. Among the liver/kidney function biomarkers, activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH), the ratio of AST/ALT and levels of total bilirubin (TBIL), direct bilirubin (DBIL), indirect bilirubin (IBIL), albumin (ALB), blood urea nitrogen (BUN), creatinine, and total protein (TP) were greater in LDA cows. Among minerals analyzed, serum Cl, Ca, and K were lower in LDA cows. After ROC analysis, it was determined that serum Ca, INS, RQUICKI, ALT, GGT, and creatinine are potential indicators for early warning and diagnosis of LDA for early postpartum dairy cows.
Dairy cows with LDA were under severe negative energy balance (NEB), had signs of liver damage and potentially lower insulin sensitivity. A combination of multi-hematological biomarkers including Ca, INS, RQUICKI, ALT, GGT and creatinine has the potential to help identify cows at risk of LDA in the early postpartum period.
左方变位的真胃（LDA）在产后早期高频发生，会影响奶牛的生产性能。LDA 的临床诊断通常通过腹部听诊和叩诊进行。本研究旨在探索血液生物标志物在奶牛 LDA 早期预警和诊断中的潜在适用性。
使用了 20 头产后早期健康奶牛和 30 头具有相似胎次的产后早期 LDA 奶牛。采用受试者工作特征曲线（ROC）方法分析了包括能量代谢生物标志物、肝/肾功能生物标志物和矿物质在内的血液生物标志物对 LDA 的敏感性。为被认为是 LDA 敏感标志物的每个选定血液生物标志物定义了一个截断点。与健康奶牛相比，LDA 奶牛的体况评分（BCS）、干物质采食量（DMI）和产奶量较低。在能量代谢标志物中，血清非酯化脂肪酸（NEFA）、β-羟丁酸（BHBA）、胰岛素（INS）和修订后的定量胰岛素敏感性检查指数（RQUICKI）水平较低，而血清胰高血糖素（GC）较高。在肝/肾功能生物标志物中，血清丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、γ-谷氨酰转肽酶（GGT）、乳酸脱氢酶（LDH）、AST/ALT 比值以及总胆红素（TBIL）、直接胆红素（DBIL）、间接胆红素（IBIL）、白蛋白（ALB）、血尿素氮（BUN）、肌酐和总蛋白（TP）的活性较高。在分析的矿物质中，LDA 奶牛的血清 Cl、Ca 和 K 较低。经 ROC 分析，确定血清 Ca、INS、RQUICKI、ALT、GGT 和肌酐是产后早期奶牛 LDA 早期预警和诊断的潜在指标。
患有 LDA 的奶牛处于严重的负能量平衡（NEB）状态，有肝损伤迹象，胰岛素敏感性可能较低。包括 Ca、INS、RQUICKI、ALT、GGT 和肌酐在内的多种血液生物标志物的组合有可能帮助识别产后早期处于 LDA 风险中的奶牛。
