Marco A.C. Mendonça1, DVM; Marcílio Nichi1, DVM, MS, PhD; Rodrigo H.F. Teixeira2, DVM, MS; Fabrício B. Rassy2, DVM; Marcelo A. de B. Vaz Guimarães1, DVM, MS, PhD
Abstract
Semen analysis is the first step towards the use of assisted reproductive techniques (i.e., artificial insemination, embryo transfer) as tools for conservation of endangered species. The aim of this study was to analyse semen samples from captive giant anteaters (Myrmecophaga tridactyla). Animals were anesthetized with 7.0 mg/kg of ketamine (Ketalar® injectable suspension 5%, Pfizer do Brasil, Guarulhos, SP, Brazil) and 0.6 mg/kg of midazolam (Dormonid® injectable suspension 10%, Roche do Brasil, Rio de Janeiro, Brazil) IM. Semen samples were collected through electroejaculation using a bipolar rectal probe connected to a commercially available electroejaculator (AC-60Hz). The regimen of electrical stimuli was composed by series of 10 stimuli in each voltage, beginning with 2 V and increasing until 6 V. Semen was assessed by a routine descriptive analysis designed to determine volume, concentration, vigor, motility, major, minor and total defects. Acrosome and cell membrane integrity were assessed through Pope's simple staining and eosine/nigrosine methods, respectively. Chromatin fragmentation was determined in a flow cytometer and mitochondrial activity was measured by a test based on the oxidation of 3,3’-diaminobenzidine (DAB). Results are presented in Table 1.
Table 1. Results of the spermatic profile from
giant anteater (Myrmecophaga tridactyla)
|
Mean
|
SEM
|
Volume (µl)
|
1279
|
±271
|
Concentration (x 106/ml)
|
129.415
|
±36.136
|
Vigor (0–5)
|
2.3
|
±0.2
|
Motility (%)
|
33
|
±6
|
Major defects (%)
|
54
|
±6
|
Minor defects (%)
|
11
|
±2
|
Total defects (%)
|
64
|
±6
|
Acrosome integrity (%)
|
84
|
±31
|
Cell membrane integrity (%)
|
81
|
±4
|
Chromatin fragmentation (%)
|
13.2
|
±3.7
|
Mitochondrial activity class I (%)
|
66
|
±6
|
Mitochondrial activity class II (%)
|
19
|
±3
|
Mitochondrial activity class III (%)
|
8
|
±2
|
Mitochondrial activity class IV (%)
|
4
|
±1
|
Mitochondrial activity class V (%)
|
3
|
±1
|
Acknowledgments
The authors thank the following institutions: Parque Municipal Quinzinho de Barros, Sorocaba; Parque Zoológico Municipal de Bauru; Bosque Dr. Fábio Sá Barreto, Ribeirão Preto; Zoológico Paraíso das Aves Jarinu; Parque Zoológico Municipal de Guarulhos; Criador Conservacionista Alphavillage, Itu.