title: Effect of egg yolk concentration on cryopreserving Spanish ibex (Capra pyrenaica) epididymal spermatozoa.
abstract: Tris-egg yolk based diluents provide adequate cryoprotection for the sperm of most wild species in which they have been tested. The objective of the current study was to evaluate various Tris-based diluents containing different concentrations of egg yolk, for the fertilizing ability of epididymal spermatozoa of the Spanish ibex (Capra pyrenaica) after freezing and thawing. For this purpose, we used heterologous in vivo fertilization by intrauterine insemination of domestic goats (Capra hircus). In Experiment 1, a Tris-citric acid-glucose (TCG) diluent containing 6% (v/v) egg yolk and a TCG extender containing 20% egg yolk were compared. In Experiment 2, a TCG-6% egg yolk extender was compared with Triladyl-20% egg yolk. Diluted samples were cooled slowly to 5 degrees C over 1 h and equilibrated at that temperature for 2 h. At that point, aliquots of samples were loaded into 0.25 ml straws, and frozen in nitrogen vapor for 10 min. The fertility of spermatozoa frozen in TCG-6% egg yolk was higher (P<0.05) than for those extended with TCG-20% egg yolk, and tended to be higher than for those frozen with Triladyl-20% egg yolk. From the results of this study, the use of Tris-based extenders containing low concentrations of egg yolk (6%) is recommended for cryopreserving Spanish ibex epididymal spermatozoa.
authors.affiliation: Departamento de Reproducción Animal, Avda. Puerta de Hierro Km 5,9, INIA, 28040 Madrid, Spain. moreno@inia.es
authors.forename: Julián
authors.initials: J
authors.lastname: Santiago-Moreno
authors.forename: Adolfo
authors.initials: A
authors.lastname: Toledano-Díaz
authors.forename: Antonio
authors.initials: A
authors.lastname: Pulido-Pastor
authors.forename: Jesús
authors.initials: J
authors.lastname: Dorado
authors.forename: Amelia
authors.initials: A
authors.lastname: Gómez-Brunet
authors.forename: Antonio
authors.initials: A
authors.lastname: López-Sebastián
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004530:Egg Yolk; D004822:Epididymis / Q000166:cytology*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D006041:Goats / Q000502:physiology*; D008297:Male; D011247:Pregnancy; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013076:Sperm Count / Q000662:veterinary; D013081:Sperm Motility / Q000502:physiology; D013094:Spermatozoa
chemical_list: D003451:Cryoprotective Agents