Clinical utility of plasma progesterone and blood and plasma glucose concentrations in predicting parturition in Holstein cows

摘要

predicting parturition is urgently needed in the dairyindustry. The objective of this study was to evaluatechanges in plasma progesterone concentration ([prog])and glucose concentration in whole blood ([gluc]_b) andplasma ([gluc]_p) as predictors of parturition within 6,12, and 24 h in primiparous and multiparous Holsteincows. Blood samples were obtained daily at approximately0900 h from 34 primiparous and 72 multiparousHolstein cows in late gestation and the time of calvingrecorded to the nearest hour. Plasma [prog] wasmeasured using an ELISA, and [gluc]_b and [gluc]p usinga low-cost point-of-care glucose meter. The optimalcut-point for predicting parturition was determined usingbinomial logistic regression with general estimatingequations, because the data set consisted of repeatedmeasures for each cow. Diagnostic test performance wasevaluated by comparing the area under the receiver operatingcharacteristic curve (AUC) and calculating thesensitivity, specificity, and κ at the optimal cut-pointfor predicting parturition. Plasma [prog] was the mostaccurate predictor of parturition within 24 h (AUC =0.96) and 12 h (AUC = 0.93), whereas [gluc]b was themost accurate predictor of parturition within 6 h (primiparous,AUC = 0.96; multiparous, AUC = 0.86). Weconclude that a decrease in plasma [prog] is currentlythe most accurate test for predicting calving within 24h. Measurement of [gluc]b is a promising new test forthe cow-side prediction of parturition in dairy cows dueto its accuracy, practicality, and low cost.