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 奶牛酮病可严重损害奶牛生产性能。本研究通过检测围产期血液代谢参数变化，以预测奶牛产后酮病的发生。分别在分娩前后对奶牛进行体况评分（Body Condition Score, BCS）。采集63头奶牛从产犊前10天至产犊后10天的血液样本，检测包括β-羟丁酸（β-hydroxybutyric acid, BHBA）、非酯化脂肪酸（non-esterified fatty acid, NEFA）、葡萄糖（glucose, GLU）、总胆红素（total bilirubin, TBIL）、直接胆红素（direct bilirubin, DBIL）、间接胆红素（indirect bilirubin, IBIL）、总蛋白（total protein, TP）、白蛋白（albumin, ALB）、球蛋白（globulin, GLO）、丙氨酸氨基转移酶（alanine aminotransferase, ALT）、天冬氨酸氨基转移酶（aspartate aminotransferase, AST）在内的多项代谢指标。本研究中奶牛产后亚临床酮病发病率为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）、NEFA（R=0.45）与产后酮病呈显著正相关。产后奶牛血浆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）分析结果显示，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及BHBA>0.43mmol/L的奶牛，产后发生亚临床酮病的风险较高。上述指标可作为风险预测指标，用于预判奶牛产后亚临床酮病的发生。