Biometry of the Reproductive System and the Ejaculation Response of Maned Wolf (Chrysocyon brachyurus) to Electroejaculation Procedure

Introduction - The Maned Wolf (Chrysocyon brachyurus) is the largest south American canid and despite of its wide distribution, inhabiting open formations in South America, this species is listed as a Near Threatened [1]. With the increasing fragmentation of the Cerrado habitat and the perspective that in short time fewer natural isolated areas remains, a genetic management is imperative in order to maintain viable populations among these areas.

Objectives - Therefore, the knowledge of the reproductive system biometry as well as the development of sampling procedures and gametes preservation techniques are fundamental for the preservation of the genetic information. The objective of the present work is to study the biometry of the reproductive system of Maned Wolf as well as to evaluate the ejaculation response of this species to electroejaculation procedure.

Materials and methods - Semen samples were obtained through electroejaculation between March and April 2005 from 06 captives Maned Wolves in: Mogi Mirim – SP (n=1); São Bernardo – SP (n=1); Sorocaba – SP (n=1); Volta Redonda – RJ (n=1) and Araxá –MG (n=2), some of the animals were sampled twice with a month of interval between the sampling. In one of the studied animals it was not possible to perform the electroejaculation procedure due to the presence of urolith and the obstruction of the urethra. The animals were chemically restrained with 5 mg/kg de PV of Zoletil® (hydrocloridrate of tiletamina + zolazepan cloridrate - VIRBAC®) via IM. Immediately after chemical restrain the biometry of reproductive system was performed and a catheterization of the urethra was realized with a polypropylene catheter adequate to the size of the external urethral hole of each animal in order to empty the blade. The blade was than filled with 20 ml of a skim milk based extender (Botu-semen® -Biotech Botucatu LTDA, Botucatu-SP, Brazil) before the electroejaculation procedure starts (80 stimulus of 4 to 12 volts). Immediately after the electroejaculation procedure a catheterization of the urethra was performed in order to retrieve the material present in the blade. The obtained samples from the blade washing were than placed in plastic tubes and centrifuged for 5 minutes at 800g and evaluated forage of sperm motility (0-100%) and rate of progressive status (0-5). Data were computed by MEANS and FREQ procedure from the SAS statistical package [2]. We calculated mean values and standard deviations of age, weight, sperm motility, progressive status, penis length and height and width of testis (table 1) and verified frequencies of progeny, preputial appearance, presence of urolith, presence of spermatozoa on blade washing and ejaculation. [...]