Objective: To determine an accurate rapid method for determination of blood glucose concentration in cattle under field conditions.
Design: Prospective, randomized, controlled trial.
Animals: 62 clinically normal Holstein cattle: 34 cows and 28 calves.
Procedure: Glucose concentrations in venous blood samples were measured in duplicate using a rapid, dry-slide chemistry technique for determination of blood glucose concentration and a laboratory-based method for determination of plasma glucose concentration. Analyses of variance were used to determine whether the relationship between results of the 2 methods was affected by the status of the animals (cows vs calves) or the PCV of the blood samples. Simple linear regression was performed to determine the correlation between the 2 methods and the slope, intercept, and residual error variance of the relationship between the methods.
Results: There as a significant linear relationship between the 2 methods throughout the range of glucose concentrations. Mean difference between results of the 2 methods (results for laboratory-based method - results for rapid method) was 12.95 mg/dl (SD, 7.20 mg/dl). The PCV did not affect the relationship, and there was no difference between results of the 2 methods for cows versus calves. Correlation between means of the duplicative values determined by use of the 2 methods was high (r = 0.9462).
Clinical implications: The good correlation between the 2 procedures and the comparable precision estimates (coefficient of variation, 7.17% for laboratory-based method; coefficient of variation, 10.11% for rapid methods) indicates that using the rapid method to measure blood glucose concentration is valid in cows and calves.