Cryopreservation and characterization of canine preantral follicles.

The aim of this study was to define the population, morphological and ultrastructural characteristics of bitch preantral follicles (PAFs) and to compare the effects on the morphology of PAF of two cryopreservation techniques - slow freezing (SF) and vitrification (V) - of bitches' ovarian tissue. The average population (number per ovary) of PAFs was 48,541 ±â€¯18,366, where 94.25% were primordial (45,145 ±â€¯16,076). The average diameter of the primordial follicles was 27.5 ±â€¯4.2 µm. The overall percentage of morphologically normal PAFs was 93.66 ±â€¯6.81% for the control group, 86.16 ±â€¯11.05% after SF and 68.14 ±â€¯12.75% after V. The percentage of normal primordial follicles was 96.69 ±â€¯4.72% in control, 89.51 ±â€¯10.39% in SF and 75.32 ±â€¯9.23% in V. There was no significant difference in the overall percentage of normal PAFs among SF and the control. However, slow frozen follicles presented ultrastructural damage, while vitrified primordial and primary follicles were well preserved. In conclusion, although slow freezing seemed to be a good preserving method, vitrification was more effective than slow freezing in preserving the ultrastructure of primordial and primary follicles of bitches.

Anatomical and histological characterization of the cervix in Santa Inês hair ewes

The aim of the present study was to describe the morphology of the cervix in Santa Ines ewes. One hundred cervices were collected from females of different ages (12 to 48 months). Five types of cervical os were observed: duck-bill, flap, rosette, papilla and spiral, with duck-bill being the most predominant type (51%) overall. The average cervix length was 4.68 cm (range of 3 to 7 cm). Shorter cervices (P < 0.05) were observed in younger females (12-18 months). The number of rings was on average 5.68 (range 3 to 8). There was a positive correlation between cervical length and animal age (r = 0.22; P < 0.0001) and between cervical length and number of rings (r = 0.21; P < 0.0001). Cervical rings were generally funnel-shaped and the mean internal diameter of the rings was 2.98 mm. The average number of rings with fornix was 5.17. The presence of fornix in the first three rings was higher than in the subsequent rings, gradually decreasing until the seventh ring. The internal shape of the cervix resembled two inverted cones, being wider at both ends and narrower in the middle. Differences in the internal characteristics of the cervical canal (length, diameter, number of rings, and number of fornices) were observed only between some of the cervical os shapes, and the success of the cervical passage cannot be predicted by the determination of the cervical os shape. Some anatomical features of the cervical canal in Santa Inês ewes differ from those reported for other sheep breeds, showing that information obtained can be useful to define the characteristics of devices to be used for achieving successful cervical penetration during insemination of Santa Inês ewes.(AU)

Anatomical and histological characterization of the cervix in Santa Inês hair ewes

The aim of the present study was to describe the morphology of the cervix in Santa Ines ewes. One hundred cervices were collected from females of different ages (12 to 48 months). Five types of cervical os were observed: duck-bill, flap, rosette, papilla and spiral, with duck-bill being the most predominant type (51%) overall. The average cervix length was 4.68 cm (range of 3 to 7 cm). Shorter cervices (P < 0.05) were observed in younger females (12-18 months). The number of rings was on average 5.68 (range 3 to 8). There was a positive correlation between cervical length and animal age (r = 0.22; P < 0.0001) and between cervical length and number of rings (r = 0.21; P < 0.0001). Cervical rings were generally funnel-shaped and the mean internal diameter of the rings was 2.98 mm. The average number of rings with fornix was 5.17. The presence of fornix in the first three rings was higher than in the subsequent rings, gradually decreasing until the seventh ring. The internal shape of the cervix resembled two inverted cones, being wider at both ends and narrower in the middle. Differences in the internal characteristics of the cervical canal (length, diameter, number of rings, and number of fornices) were observed only between some of the cervical os shapes, and the success of the cervical passage cannot be predicted by the determination of the cervical os shape. Some anatomical features of the cervical canal in Santa Inês ewes differ from those reported for other sheep breeds, showing that information obtained can be useful to define the characteristics of devices to be used for achieving successful cervical penetration during insemination of Santa Inês ewes.