title: Use of commercial extenders and alternatives to prevent sperm agglutination for cryopreservation of brown bear semen.
abstract: The objective of this study was to evaluate different bovine and canine commercial semen extenders for cryopreservation of brown bear ejaculates and the effect of semen collection directly into extender on sperm agglutination. Semen samples were obtained by electroejaculation from 13 adult males. In experiment 1, eleven ejaculates from eight bears were used to evaluate Bioxcell and Andromed as extenders, whereas in experiment 2, nine ejaculates from six bears were used to evaluate Triladyl canine, CaniPro, and Extender 2 as extenders. An extender specifically developed for brown bears (Test-Tris-fructose-egg yolk-glycerol, TTF-ULE/bear) served as a control extender in both experiments. After thawing, total and progressive sperm motility and sperm viability were greater (P < 0.05) for TTF-ULE/bear and Andromed extenders than for Bioxcell in experiment 1 and greater (P < 0.05) for TTF-ULE/bear extender than for Triladyl Canine, CaniPro, and Extender 2 in experiment 2. In experiment 3, addition of handling extender (TTF-H) to the semen collection tube for eight ejaculates from seven bears resulted in less (P < 0.05) sperm agglutination in fresh samples (score 0.5 ± 0.2 vs. 1.8 ± 0.4 in diluted and control samples, respectively) with no effect on pre-freeze and post-thawing semen quality. In conclusion, TTF-ULE/bear is the most suitable extender for brown bear semen cryopreservation, but comparable results can be obtained with the commercial extender Andromed. In addition, collection of ejaculates directly in TTF-H extender decreases sperm agglutination in fresh samples.
authors.affiliation: ITRA-ULE, INDEGSAL, University of León, León, Spain; Animal Reproduction and Obstetrics, University of León, León, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Gomes-Alves
authors.affiliation: ITRA-ULE, INDEGSAL, University of León, León, Spain; Animal Reproduction and Obstetrics, University of León, León, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Alvarez
authors.affiliation: ITRA-ULE, INDEGSAL, University of León, León, Spain; Animal Reproduction and Obstetrics, University of León, León, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Nicolas
authors.affiliation: ITRA-ULE, INDEGSAL, University of León, León, Spain; Animal Reproduction and Obstetrics, University of León, León, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Lopez-Urueña
authors.affiliation: ITRA-ULE, INDEGSAL, University of León, León, Spain; Molecular Biology, University of León, León, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Martínez-Rodríguez
authors.affiliation: Cabárceno Park, Cantabria, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Borragan
authors.affiliation: ITRA-ULE, INDEGSAL, University of León, León, Spain; Molecular Biology, University of León, León, Spain. Electronic address: ppazc@unileon.es.
authors.forename: P
authors.initials: P
authors.lastname: de Paz
authors.affiliation: ITRA-ULE, INDEGSAL, University of León, León, Spain; Animal Reproduction and Obstetrics, University of León, León, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Anel
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D008297:Male; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013073:Sperm Agglutination / Q000187:drug effects*; D001503:Ursidae / Q000502:physiology*
keywords: Brown bear ejaculates; Cryopreservation extender; Sperm agglutination; Spermatozoa freezability