Caracterización morfométrica y evaluación de la calidad de COC´s de acuerdo con el ciclo estral en la especie Felis catus

Abstract

Currently, there is a high interest in biotechnology for assisted reproduction in the domestic cat, because the information obtained can be transferred to wild felids. The objective of the present investigation was to describe the morphological changes in vaginal and uterine cytology that occur during the different stages of the estrous cycle and the association of these changes with the characteristics of the ovaries, the state of development of the follicles and the quality of the oocyte. For this study, 20 female cats were used, which underwent a pre-surgical vaginal cytology and a post-surgical cytology at the uterine level. The morphometry of the ovaries obtained was obtained according to the different stages of the cycle: anestrus, proestrus and estrus, where there were no statistical differences (p>0.05), the mean value per ovary being 0.44 cm wide, 1.00 cm long and 0.14 g in weight. The number of ovarian follicles >2 mm< in diameter was lower (p>0.05) in anestrus (18.00 ± 5.29) than in proestrus (31.44 ± 11.28) and estrus (25.28 ± 8.03). The evaluation of the amount of oocyte cumulus complexes (COC's) did not differ statistically, it was 21.50 ± 10.08 in anestrus, 35.56 ± 11.23 in proestrus and 33.00 ± 11.70 in estrus (p>0.05), however, when COC's were assessed by cresyl brilliant blue staining, it was determined that a greater number of COC'S (p<0.05) resulted to be BCB positive in proestrus stage 18.67 ± 5.24 vs. 9.75 ± 4.64 anestrus and 18.00 ± 5.32 estrus. Finally, the oocyte morphometric variables had no statistical differences between cycle stages (p>0.05). In conclusion, the morphometric characteristics of the ovaries, the number of follicles and oocyte characteristics are statistically similar regardless of the stage of the estrous cycle. Likewise, the BCB test proved to be a useful methodology to categorize oocytes from female cats.