[Inmunoenzymatic assay used to determine reproductive losses and as a toll for reproductive management decision-taking in dual-purpose cows in the tropics] | Determinacion de progesterona mediante un ensayo inmunoenzimatico para toma de decisiones de manejo reproductivo y determinacion de estas perdidas en vacas de doble proposito mantenidas en clima tropical

English. The objective of present study was to evaluate an immunoenzymatic assay (IEA) to both confirm estrus and early pregnancy diagnosis, adn the reproductive losses occuring between oestrus and 45 days post-artifical insemination (AI) in dual-purpose cows. Two experiments were conducted, and in both of them, the detection of estrus was done three times per day; Al was done using conventional methods and pregnancy diagnosis was done by rectal palpation practiced at 45 days post-Al. In experiment 1, a completely random design was used progesterone determinations at time of estrus and at 23+-1 days post-Al. In comparison to radioinmunoasay (RIA), IEA presented 7.1 % of failures at detecting estrus, and 4.3 % of error at detection gestation. In experiment 2, a completely random design was used with no treatments and no restrictions, blood samples were taken by punction of yugular vein at the time of estrus and 23+-1 days post -Al. In comparison to RIA, the EIA results showed 0 % of error in the confirmation estrus, and the majority of the reproductive losses 92 % ocurred between the day of AI and 23+-1 days post AI

Spanish; Castilian. Los objetivos fueron evaluar un ensayo inmunoenzimatico (eIe) para determinar progesterona (P4) en leche para confirmar el estreo, diagnosticar y determinar las perdidas reproductivas entre el estro y los 45 dias posteriores a la inseminacion artifical (IA) en vacas de doble proposito. Se realizaron 2 experimentos. En el experimento 1, se uso un diseno completamente al azar (n=47), se tomaron en forma simultanea muestras de leche y sangre para ser analizadas por el eIe y por el radioinmunoanalisis (RIA) para determinar P4 al momento del estro y a los 23+- dias posteriores. Con respecto al RIA, el EIE tuvo un 7.1 % de error para confirmar el estro y un 4.3 % de error para la gestacion. En el experimento 2, se uso un diseno completamente al azar sin tratamientos ni restricciones (n=47), se tomaron muestras de sangre por puncion de la vega yugular al momento del estro y a los 23+-1 dias posteriores a la IA. Con base en el RIA los datos indicaron que el eIe determino 0 % de error en la confirmacion de estros, mientras que el 92 % de las perdidas reproductivas ocurrieron entre la IA y el dia 23+-1 posterior a la IA.