Subclinical ketosis risk prediction in dairy cows based on prepartum metabolic indices

ABSTRACT Ketosis can seriously impair cow performance. This study detected changes in prepartum blood metabolic parameters for predicting postpartum ketosis occurrence in dairy cows. Body condition score (BCS) was assessed before and after delivery. Blood samples of 63 cows were collected from 10 days before calving to 10 days after calving to measure metabolic parameters including β-hydroxybutyric acid (BHBA), non-esterified fatty acid (NEFA), glucose (GLU), total bilirubin (TBIL), direct bilirubin (DBIL), indirect bilirubin (IBIL), total protein (TP), albumin (ALB), globulin (GLO), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). There was a postpartum subclinical ketosis incidence of 42.25%. Compared with prepartum, plasma, levels of BHBA, AST, and NEFA significantly increased postpartum, and prepartum AST (R=0.57) and NEFA (R=0.45) showed a significant positive correlation with ketosis postpartum. Plasma GLU level significantly decreased postpartum and was significantly negatively correlated with ketosis (R=-0.21). Receiver operating characteristic curve analysis revealed prepartum BSC < 2.88, and prepartum plasma AST > 68.0 U/L, GLU < 3.97mmol/L, NEFA > 0.27mmol/L, and BHBA > 0.43mmol/L, indicating a high risk of subclinical ketosis postpartum. These levels can be used as risk indicators to predict the occurrence of subclinical ketosis in postpartum cows.

摘要：酮病会严重损害奶牛的生产性能。本研究通过检测围产期血液代谢指标的变化，以期预测奶牛产后亚临床酮病的发生风险。研究分别在分娩前后对63头奶牛的体况评分（BCS）进行评定，并于产犊前10天至产犊后10天期间采集血液样本，检测包括β-羟丁酸（BHBA）、非酯化脂肪酸（NEFA）、葡萄糖（GLU）、总胆红素（TBIL）、直接胆红素（DBIL）、间接胆红素（IBIL）、总蛋白（TP）、白蛋白（ALB）、球蛋白（GLO）、丙氨酸氨基转移酶（ALT）以及天冬氨酸氨基转移酶（AST）在内的多项代谢指标。受试奶牛产后亚临床酮病的发病率为42.25%。与产前相比，产后奶牛血浆中BHBA、AST及NEFA水平显著升高；且产前AST（R=0.57）与NEFA（R=0.45）水平与产后酮病呈显著正相关。产后血浆GLU水平显著降低，且与酮病呈显著负相关（R=-0.21）。受试者工作特征曲线（Receiver Operating Characteristic curve，ROC曲线）分析显示，产前体况评分<2.88、产前血浆AST>68.0 U/L、GLU<3.97mmol/L、NEFA>0.27mmol/L以及BHBA>0.43mmol/L，均提示奶牛产后存在较高的亚临床酮病风险。上述指标可作为风险预测因子，用于预测奶牛产后亚临床酮病的发生。