| Popis: |
El objetivo fue evaluar tratamientos de sincronización del estro en vaquillonas HU. 276 vaquillonas cíclicas fueron divididas al azar en: G1, n = 60 con cuerpo lúteo (CL) fueron inyectadas i.m. con delprostenate, 400 µg (Glandinex®, Ono-Pharmaceutical, Japan). G2, n = 49, implante auricular subcutáneo con norgestomet, 3,0 mg, durante 9 días más norgestomet i.m., 3,0 mg y valerato de estradiol i.m., 5,0 mg (Crestar®, Intervet, Holanda), al día 7 se inyectó delprostenate i.m., 400 µg. G3, n = 50, igual al G2 más eCG i.m., 500 UI (Folligon®, Intervet, Holanda) al día 9. G4, n = 52, se colocó un dispositivo intravaginal con progesterona (CIDR-B®, Easy-Breed, Lab. Hamilton, NZ) durante 7 días y benzoato de estradiol i.m., 3,0mg (Estradiol ®, Lab. Dispert, Uruguay), al día 7 se inyectó delprostenate i.m., 400µg. G5, n = 65, el día 0 se inyectó gonadorelina i.m., 250µg (Fertagyl®, Intervet, Holanda) y al día 7 delprostenate i.m., 400 µg. Se controlaron estros durante 5 días, inseminando 12 horas post celo visto. Al día 27 post IA se diagnosticó gestación mediante ultrasonografía. Los resultados fueron analizados mediante test X² con corrección de Yates. El 86,7% de presentación de estro del G1 fue inferior (P < 0,001) al G2, G3, G4 y G5 (100,0% respectivamente). Los porcentajes de concepción del G1 (86,5%), G4 (75,0%) y G5 (80,0%) fueron superiores (P < 0.001) al G2 (49,0%) y G3 (64,0%). El porcentaje de preñez del G2 (49,0%) fue inferior (P < 0,001) al G1 (86,5%), G3 (64,0%), G4 (75,0%) y G5 (80,0%). Teniendo en cuenta los porcentajes de concepción y preñez, se concluye que los tratamientos más eficientes fueron los del G1, G4 y G5. The objective of this study was to evaluate different treatments of estrous synchronization in Uruguayan Holstein heifers. 276 cycling heifers were randomly divided in: G1, n = 60 with CL were injected i.m. with 400 µg of delprostenate, (Glandinex®, Ono-Pharmaceutical, Japan). G2, n = 49, subcutaneous ear implant with 3.0 mg of norgestomet during 9 days plus 3.0 mg i.m. of norgestomet and 5.0 mg estradiol valerate (Crestar®, Intervet, Holland), on day 7 400 µg of delprostenate i.m. was injected with withdrawal of ear implant at day 9. G3, n = 50, similar to the G2 plus 500 UI of eCG i.m. (Folligon®, Intervet, Holland) on day 9. G4, n = 52, an intravaginal device with progesterona was placed (CIDR-B®, Easy-Breed, Lab. Hamilton, NZ) during 7 days and 3.0 mg i.m. of estradiol benzoate (Estradiol®, Lab. Dispert, Uruguay), on day 7 i.m. 400 µg of delprostenate was injected. G5, n = 65, on day “0” 250 µg i.m. of gonadoreline (Fertagyl®, Intervet, Holland) and on day 7 400 µg i.m. of delprostenate. Estrous was controlled during 5 days after end of each treatment, artificial insemination was carried at detected estrous. On day 27 from AI pregnancy rate was detected by ultrasonography. The results were analyzed by means of X² with Yate´s correction. 86.7% of estrous presentation of G1 was inferior P < 0.001) to G2, G3, G4 and G5 (100.0% respectively). The conception rate of G1 (86.5%), G4 (75.0%) and G5 (80.0%) it were superior (P < 0.001) compared to G2 (49.0%) and G3 (64.0%). The pregnancy rate of G2 (49.0%) was lower (P < 0.001) compared to G1 (86.5%), G3 (64.0%), G4 (75.0%) and G5 (80.0%). Keeping in mind the conception and pregnancy rates, we conclude that the most efficient treatments were those of the G1, G4 and G5. 512 - 516 Bimestral |
