[Plassmatie progesterone in bovine embryos recipient by Elisa] | Progesterona plasmatica en receptoras de embriones bovinos por el metodo de Elisa

English. In order to know early pregnant, plasma progesterone (P4) concentration were determined by Enzyme Linked Immunosorbent Assay (ELISA) in 47 crossbred bovine embryos recipient heifers. Pregnancy status was confirmed by rectal palpation 60 days after estrus. Pregnancy rates were 38.3 (18/47) while a 61.7 stayed open. Simple linear regression, one way analysis of variance and chi-square analysis indicated that there were not differences (P0.05) between plasma P4 concentrations of females which remained pregnant and those which did not on either days 0 (estrus) or 7 (ET). On day 21, the mean +- SD concentration of P4 in pregnant females was 12.2 +- 2.2 ng/ml being significantly higher (P0.05) compared to non-pregnant females (0.82 +- 0.42 ng/ml). Recipients having plasma P4 concentration of 2 ng/ml or more on day 21, were considered as pregnant. The accuracy of this test for evaluating the concentrations of P4 the days 21 to 24 after estrus gives a high percentage of safety in the early diagnosis of pregnant, to recycle the open recipent before 60 days post estrus, reducing thus, the maintenance cost of them

Spanish; Castilian. Con la finalidad de tener diagnostico de prenez precoz, se determinaron las concentraciones de progesterona (P4) plasmatica por Enzimoinmunoanalisis (ELISA), de 47 novillas mestizas receptoras de embriones bovinos. La tasa de prenez se confirmo por palpacion transrectal a los 60 dias post TE. De las 47 transferencias, 18 receptoras (38,3) resultaron prenadas y 29 (61,7) vacias. La regresion lineal, el analisis de varianza y de Ji cuadrado, no demostraron (P0,05) diferencias entre las concentraciones de P4 de receptoras prenadas y vacias para los dias 0 (celo) y 7 (TE) del ciclo estral. Para el dia 21, las concentraciones de P4 en prenadas, fueron mas altas (P0,05) (12,2 +- 2,2 ng/ml) que en vacias (0,82 +- 0,42 ng/ml). El dia 21 post celo se obtuvo un 75 de efectividad en la deteccion de prenadas y un 100 en vacias utilizando las concentraciones de P4 (2 ng/ml de p4 como criterio discriminatorio). Se concluye que la determinacion de las concentraciones de P4 entre los dias 21 a 24 post celo proporciona un alto porcentaje de seguridad en el diagnostico precoz de hembras vacias, para reciclarlas antes de los 60 dias post celo, logrando disminuir asi los costos de mantenimiento de las mismas