Características ováricas y hormonales de la cobaya en diferentes etapas del ciclo estral

Abstract

The objective of this research was to evaluate the ovarian and hormonal characteristics of the guinea pig after heat synchronization with oral progesterone. The study was carried out in the Biotechnology laboratory of the Faculty of Agricultural Sciences of the University of Cuenca. Forty-three guinea pigs between 4 and 5 months of age were used, with an average weight of 886,2 ± 12,80 grams, they were synchronized for 15 days with oral progesterone (P4) (Altrenogest) for the subsequent assessment of the vaginal membrane, cytology, blood sampling, evaluation of ovarian morphology, antral follicle count and corpus luteum, as well as the classification of COC's obtained at five moments of the estrous cycle day (15, 1, 4, 8 and 11). The results showed that the oral administration of P4 at a dose of 0.22 mg/kg of body weight for 15 days allowed 94.1% of guinea pigs to present vaginal membrane opening (AMV). A mean of 30.1 antral follicles of different sizes available for aspiration was determined, that is, 15.1 follicles/ovary. Collecting 1,249 suitable COC's through the follicular aspiration technique, of which 61.5% come from follicles between (0.5-1 mm), 60% (less than 0.5 mm) and 71.4% (greater than 1 mm). In conclusion, it is confirmed that the follicular dynamics in the guinea pig is biphasic, in addition, the corpus luteum has a growth, static and regression phase and that the preovulatory follicle measures between 0.5-1 mm and that this class of follicles are the ones that provide COC's of the highest quality.