Collection and evaluation of semen from the Capybara Hydrochoerus hydrochaeris

Objective. Determine the characteristics of semen and morphometry of the Capybara (Hydrochoerus hydrochaeris) spermatozoid. Materials and methods. 10 males, weighing between 21-45 kg, which were restrained and anesthetized, were used in the study. The semen sample was obtained by electroejaculation and the color, volume, pH, mass motility, individual motility, viability, concentration and morphology were determined. Measurements of the head and tail of spermatozoids were also conducted. Results. Semen was obtained from 100% (10/10) of the animals. The highest number of ejaculations (80%; 8/10) was obtained with a maximum voltage of 6V. The color was white, of a milky appearance, average values were volume 135.5 ± 93.56 ?l, pH 8.14 ± 0.38, mass motility 32.60 ± 13.46%, individual motility 34 ± 19.81%, viability 19.42 ± 51.3%, sperm concentration 127 ± 59.01x106 spermatozoids / mL and morphology 51.3 ± 19.42 normal spermatozoids. The head length was 5.41 ± 0.7?m, the width of head 3.77 ± 0.5 and head area 75.66 ± 20.6 ?m2. The tail length was of 27.9 ± 11.3 ?m. Conclusions. Semen collection by electro ejaculation was successful, without presenting significant differences in semen characteristics and spermatozoid morphology with other smaller wild rodents, although there was a high variability of these characteristics observed between the animals sampled, possibly due to the heterogeneity of the experimental animals.