Evaluation of Fresh and Thawed Semen of Pecari tajacu (Artiodactyla: Tayassuidae) in Yucatán Mexico

This research aimed to characterize the seminal properties of collared peccary Pecari tajacu before and after freezing, and to relate the morphometric measurements of the testes with sperm measurements before freezing. The study design was quasi-experimental in nature. The investigation was carried out at the Xmatkuil Wildlife Management and Conservation Unit and the Centennial Zoo in the state of Yucatan, Mexico, during the months of October to December 2001. Seventeen collared pecaries adult were electroejaculation from two captive populations. Macro and microscopic analyzes of fresh and thawed semen were carried out, also morphometric measurements of the testes, the data of sperm measurements were compared with Student´s  t-test, a linear regression model was adjusted between spermatic and morphometric variables of the testis. Logistic regression was performed between seminal freezability and spermatic and morphometric variables. The ejaculate volume was 0.96 ± 0.98 ml, with 62.08 ± 19.10% sperm motility, concentration of 558.61 ± 537.04 x 106 spermatozoa / ml of fresh semen and vigor of 3.7 ± 0.58 on a scale of 1 to 5. On thawing the motility sperm was 35 ± 17.18% and 2.75 ± 0.62 vigor. The measurements of the sperm cell segments did not show a significant difference between the individuals of the two populations. Testicular width and sperm concentration were fitted to the logistic regression model with freezability (1 = yes, 0 = no). It is concluded that testicular width is a factor significantly associated with sperm motility and seminal freezability.