title: Seasonality, estrous cycle characterization, estrus synchronization, semen cryopreservation, and artificial insemination in the Pacific white-sided dolphin (Lagenorhynchus obliquidens).
abstract: The reproductive physiology of the Pacific white-sided dolphin, Lagenorhynchus obliquidens, was characterized to facilitate the development of artificial insemination (AI) using cryopreserved spermatozoa. Specific objectives were to: 1) describe reproductive seasonality of the Pacific white sided dolphins; 2) describe urinary LH and ovarian steroid metabolites during the estrous cycle; 3) correlate LH and ovarian steroidal metabolite patterns to ultrasound-monitored follicular growth and ovulation; and 4) assess the efficacy of synchronizing estrus, sperm collection/cryopreservation, and intrauterine insemination. Ovulations (64%, n=37) and conceptions (83%, n=18) occurred from August to October. Peak mean serum testosterone (24 ng/ml), cross-sectional testicular area (41.6 cm(2)), and sperm concentration (144.3 x 10(7) sperm/ml) occurred in July, August, and September respectively. Spermatozoa were only found in ejaculates from July to October. Estrous cycles (n=22) were 31 d long and were comprised of a 10 d follicular and 21 d luteal phase. Ovulation occurred 31.2 h after the onset of the LH surge and 19.3 h after the LH peak. Follicular diameter and circumference within 12 h of ovulation were 1.52 and 4.66 cm respectively. Estrus synchronization attempts with altrenogest resulted in 17 (22%) ovulatory cycles with ovulation occurring 21 d post-altrenogest. Ten AI attempts using cryopreserved semen resulted in five pregnancies (50%). The mean gestation length was 356 days (range 348-367). These data provide new information on the Pacific white-sided dolphin's reproductive physiology and collectively enabled the first application of AI in this species.
authors.affiliation: SeaWorld and Busch Gardens Reproductive Research Center, Busch Entertainment Corporation, San Diego, CA 92109, USA. todd.robeck@seaworld.com
authors.forename: T R
authors.initials: TR
authors.lastname: Robeck
authors.forename: K J
authors.initials: KJ
authors.lastname: Steinman
authors.forename: M
authors.initials: M
authors.lastname: Greenwell
authors.forename: K
authors.initials: K
authors.lastname: Ramirez
authors.forename: W
authors.initials: W
authors.lastname: Van Bonn
authors.forename: M
authors.initials: M
authors.lastname: Yoshioka
authors.forename: E
authors.initials: E
authors.lastname: Katsumata
authors.forename: L
authors.initials: L
authors.lastname: Dalton
authors.forename: S
authors.initials: S
authors.lastname: Osborn
authors.forename: J K
authors.initials: JK
authors.lastname: O'Brien
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary; D004289:Dolphins / Q000502:physiology*; D030762:Estrous Cycle / Q000502:physiology*; D004973:Estrus Synchronization / Q000379:methods; D005260:Female; D007315:Insemination, Artificial / Q000379:methods / Q000662:veterinary; D007986:Luteinizing Hormone / Q000652:urine; D008297:Male; D006080:Ovarian Follicle / Q000000981:diagnostic imaging; D010060:Ovulation; D011247:Pregnancy; D011256:Pregnancy Outcome; D011374:Progesterone / Q000819:agonists; D012098:Reproduction / Q000502:physiology*; D027724:Reproductive Techniques, Assisted / Q000662:veterinary*; D012621:Seasons; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary; D013076:Sperm Count / Q000662:veterinary; D013737:Testis / Q000000981:diagnostic imaging; D013739:Testosterone / Q000097:blood; D014204:Trenbolone Acetate / Q000031:analogs & derivatives / Q000627:therapeutic use; D014463:Ultrasonography
chemical_list: C023445:altrenogest; D013739:Testosterone; D011374:Progesterone; D007986:Luteinizing Hormone; D014204:Trenbolone Acetate