Descripción macroscópica y microscópica de ovarios de alpaca (Vicugna pacos) durante la etapa fetal

Abstract

The aim of this work was to describe macroscopically and microscopically the ovaries of alpacas during the fetal stage. We worked with 18 female fetuses collected at the Huancavelica Municipal Slaughterhouse, from alpacas destined for human consumption. The process and analysis of the collected samples was performed at the Faculty of Veterinary Medicine - UNMSM, in Lima, Peru. Fetal age was calculated by measuring the biparietal diameter and divided into three groups: Group I (60 - 150 days), Group II (151 - 239 days) and Group III (240 - 335 days). The weight of the ovaries was 0.02 ± 0.01, 0.03 ± 0.01 and 0.03 ± 0.01 grams in the first, second and third group, respectively. The ovaries were paired, oval-shaped, with a smooth, cream surface, located in the sublumbar region at the level of the 6th and 7th lumbar vertebrae. The cortex and medulla were visible from the third month. Microscopically, in Group I, we observed oogonium, the distinction between cortex and medulla, unilaminar primary follicles, atresia and segmentation of the germ cells. In Group II, we observed preantral primary follicles. In Group III, we observed preovulatory follicles. We concluded that, from day 68 of the fetal stage of the alpaca, ovaries have macroscopic characteristics similar to those of an adult alpaca. Microscopically, they presented ovogonia, primordial follicles, unilaminar primary follicles, preantral follicles, preovulatory follicle, as well as the degeneration of the germ cells.