The objective of this study was to compare the results of some parameters of seminal quality of bulls obtained by the Conventional method and also by the computerized CASA system, other objective was to determinate if there is any difference in seminal quality between Jersey, Holstein and Brown Swiss bulls. Semen samples were collected from 5 bulls and were analyzed by the conventional method which parameters are: Individual motility (%), Mass motility (1-5), Neubauer chamber concentration (106 spermatozoa/ml) and individual post-freezing motility (%). The same samples were analyzed by CASA method, which variables are: Total motility (%), Progressive motility (%), concentration (106 spermatozoa/ml) and total post-freezing motility (%). Results obtained by each breed of bulls in these parameters were compared using a Duncan multiple range test to assess statistical differences. The result was that Jersey bull's semen had the higher counts for most o the variables compared with the other two. The entire population of results by the Conventional method was also compared against the entire population of results by CASA, in those parameters that are equivalent between the two methods: motility (individual vs total), concentration (Neubabuer vs CASA) and post-freezing motility. This comparison was performed with a Student test that proved there were differences between the two methods in all the studied parameters. In the case of motility, the conventional method showed an average 79% against the 75.56% of the CASA system. In concentration, the conventional method had a result of 762.83 million spermatozoa/ml which was inferior that the 819.3 millions spermatozoa/ml of the CASA method. Finally, about the post-freezing motility the conventional method had the highest result with 65.36% against the 59.64% of CASA. The conclusion was that the numeric results of spermatic quality are different depending on which method is used.

La incorporación de técnicas diseñadas para controlar la dinámica folicular y la ovulación en los últimos años ha reducido los problemas asociados con la detección de celos y permitido sistematizar en gran medida los trabajos reproductivos.  Es posible optar por distintos tratamientos de sincronización de celos que van desde los más simples, que utilizan inyecciones periódicas de prostaglandina F2α, a los más complejos, que utilizan GnRH o dispositivos con progesterona, la adición de gonadotrofina coriónica equina (eCG) a los tratamientos con dispositivos con progesterona y estradiol ha brindado la posibilidad de aplicar la IATF con altas tasas de preñez en vacas para leche cíclicas y no cíclicas. El objetivo del estudio fue determinar la tasa de ovulación con el efecto de la hormona gonadotropina coriónica equina (eCG) sobre el tamaño del folículo preovulatorio (FPO), cuerpo lúteo en el día 7  (CL7) y tasa de preñez a 35 días de vacas Holstein friesian mestizas en la provincia de Pastaza. Se aplicaron dos tratamientos (T): TA= DIB+BE+PG; TB= TA+ eCG (día 8), se usó un protocolo de inseminación artificial a tiempo fijo (IATF). Se utilizaron 100 vacas Holstein mestizas, multíparas en periodo posparto entre 60 a 150 días, condición corporal de 2.25 a 2.75; el sistema de alimentación se basó en pastoreo al sogueo con pasto gramalote (Axonopus scoparius). Para el análisis de datos se utilizó software estadístico Minitab ® 17 en su versión de prueba.  El FPO en el TA alcanzaron un diámetro de 15,00 mm y el TB, 13.80 mm (P>0.05). No se encontró diferencia significativa. En condiciones de la región amazónica el tamaño del FPO y  CL, no se incrementó con la administración de eCG en la IATF.