Cut-off Point of Glutathione Peroxidase(GSH-PX) for the Diagnosis of Endometritis in Dairy Cows

Abstract:

The cut-off point of a diagnostic test is the determination of the minimum value at which an individual can be diagnosed as sick. To obtain a good position, an analysis is carried out using a statistical ROC Curve (Receiver Operating Characteristic), which is used in determining the value of the diagnosis with the highest sensitivity and specificity. The cut-off value of glutathione peroxidase (GSH-Px) for the diagnosis of uterine diseases is not described. The minimum tolerable value can be described for 130 U/g Hb; the value has been used as a limit under which it has a marginal deficiency of Se. Therefore, the objective of this work was to determine the cut-off point of the GSH-Px values that allows diagnosing cows with endometritis, in dairy herds in the province of Santa Fe, Argentina. We used 115 Holstein cows between 21 and 56 postpartum days, from dairy establishments in the province of Santa Fe, Argentina. Blood samples were obtained by puncturing the coccygeal vein for determination of GSH-Px. At the same time, the uterine status of the cows was characterized in two groups: healthy cows (VS, by its initials in Spanish) and cows with endometritis, either clinical and subclinical (VE, by its initials in Spanish). To create a ROC curve, the VS and VE diagnoses must be entered under a binary system as 0 (VS) and 1 (VE). The obtained results indicate that the point or cut value for the GSH-Px was of 222 U/g Hb with a sensitivity of 81.4% and a specificity of 33.9%. That is to say, above that value, the possibility of suffering endometritis decreases significantly. We can conclude that the cut-off point of 222 U/g Hb obtained for this group of cows from establishments in the province of Santa Fe, could be considered in the future as a complementary tool to diagnose endometritis.