Publications by authors named "Todd R Robeck"

28 Publications

  • Page 1 of 1

Scaling of heart rate with breathing frequency and body mass in cetaceans.

Philos Trans R Soc Lond B Biol Sci 2021 Aug 14;376(1830):20200223. Epub 2021 Jun 14.

Fundación Oceanogràfic de la Comunitat Valenciana, Valencia, Spain 46005.

Plasticity in the cardiac function of a marine mammal facilitates rapid adjustments to the contrasting metabolic demands of breathing at the surface and diving during an extended apnea. By matching their heart rate () to their immediate physiological needs, a marine mammal can improve its metabolic efficiency and maximize the proportion of time spent underwater. Respiratory sinus arrhythmia (RSA) is a known modulation of that is driven by respiration and has been suggested to increase cardiorespiratory efficiency. To investigate the presence of RSA in cetaceans and the relationship between , breathing rate () and body mass (), we measured simultaneous and in five cetacean species in human care. We found that a higher was associated with a higher mean instantaneous (i) and minimum i of the RSA. By contrast, scaled inversely with such that larger animals had lower mean and minimum is of the RSA. There was a significant allometric relationship between maximum i of the RSA and , but not , which may indicate that this parameter is set by physical laws and not adjusted dynamically with physiological needs. RSA was significantly affected by and was greatly reduced with small increases in . Ultimately, these data show that surface s of cetaceans are complex and the patterns we observed are controlled by several factors. We suggest the importance of considering RSA when interpreting measurements and particularly how may drive changes that are important for efficient gas exchange. This article is part of the theme issue 'Measuring physiology in free-living animals (Part I)'.
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http://dx.doi.org/10.1098/rstb.2020.0223DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8200651PMC
August 2021

Epigenetic clock and methylation studies in elephants.

Aging Cell 2021 Jul 12;20(7):e13414. Epub 2021 Jun 12.

Department of Biostatistics, Fielding School of Public Health, University of California, Los Angeles, CA, USA.

Age-associated DNA-methylation profiles have been used successfully to develop highly accurate biomarkers of age ("epigenetic clocks") in humans, mice, dogs, and other species. Here we present epigenetic clocks for African and Asian elephants. These clocks were developed using novel DNA methylation profiles of 140 elephant blood samples of known age, at loci that are highly conserved between mammalian species, using a custom Infinium array (HorvathMammalMethylChip40). We present epigenetic clocks for Asian elephants (Elephas maximus), African elephants (Loxodonta africana), and both elephant species combined. Two additional human-elephant clocks were constructed by combining human and elephant samples. Epigenome-wide association studies identified elephant age-related CpGs and their proximal genes. The products of these genes play important roles in cellular differentiation, organismal development, metabolism, and circadian rhythms. Intracellular events observed to change with age included the methylation of bivalent chromatin domains, and targets of polycomb repressive complexes. These readily available epigenetic clocks can be used for elephant conservation efforts where accurate estimates of age are needed to predict demographic trends.
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http://dx.doi.org/10.1111/acel.13414DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8282242PMC
July 2021

Multi-species and multi-tissue methylation clocks for age estimation in toothed whales and dolphins.

Commun Biol 2021 05 31;4(1):642. Epub 2021 May 31.

Department of Biostatistics, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA, USA.

The development of a precise blood or skin tissue DNA Epigenetic Aging Clock for Odontocete (OEAC) would solve current age estimation inaccuracies for wild odontocetes. Therefore, we determined genome-wide DNA methylation profiles using a custom array (HorvathMammalMethyl40) across skin and blood samples (n = 446) from known age animals representing nine odontocete species within 4 phylogenetic families to identify age associated CG dinucleotides (CpGs). The top CpGs were used to create a cross-validated OEAC clock which was highly correlated for individuals (r = 0.94) and for unique species (median r = 0.93). Finally, we applied the OEAC for estimating the age and sex of 22 wild Norwegian killer whales. DNA methylation patterns of age associated CpGs are highly conserved across odontocetes. These similarities allowed us to develop an odontocete epigenetic aging clock (OEAC) which can be used for species conservation efforts by provide a mechanism for estimating the age of free ranging odontocetes from either blood or skin samples.
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http://dx.doi.org/10.1038/s42003-021-02179-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8167141PMC
May 2021

Effects of sex, age, and season on the variation of blood analytes in a clinically healthy population of bottlenose dolphins ( spp.).

Vet Q 2020 Nov;40(1):342-352

SeaWorld and Busch Gardens Species Preservation Laboratory, SeaWorld Parks and Entertainment, San Diego, CA, USA.

Background: A comprehensive evaluation of the effects of sex, age, and season on blood analytes in a robust population size of bottlenose dolphins ( spp.) has not been investigated to date.

Aim: To define the variation in hematological and biochemical analytes of dolphins due to sex, age, and season.

Methods: 1,426 blood samples collected from 156 clinically normal dolphins consisting of 59 males and 97 females in which 37 analytes were measured were retrospectively identified. The dolphins were categorized by age, sex, and season, and categories were compared.

Results: About 23 (64%) analytes differed by age. The number of differences between adjacent age groups decreased with advancing age. MPV, glucose, BUN, globulins, GGT and Cl progressively increased with age, whereas Abs lymphs, total protein, ALP, CK and Ca progressively decreased with age. Three (8%) of analytes differed between sex, whereas 16 (44%) analytes differed by season. Female dolphins had higher median iron (33 µmol/L) than male dolphins (25 µmol/L). Female dolphins also had higher Abs lymphs and MCHC, but Abs lymphs and MCHC also differed between age and season, respectively. Sex inconsistently and relatively infrequently influences analytes. Delphinids of advancing age experience immune senescence and decreasing renal perfusion or clearance.

Conclusions: These results demonstrate the importance of considering the influences of sex, age, and season on blood data, provide a baseline for accurate interpretation of clinicopathological analytes of delphinids in managed care, and will be useful for investigations into health, disease, and stressors of wild delphinids.
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http://dx.doi.org/10.1080/01652176.2020.1845415DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7733981PMC
November 2020

Comparative analysis of steroids in cyclic and pregnant killer whales, beluga whales and bottlenose dolphins by liquid chromatography tandem mass spectrometry.

Gen Comp Endocrinol 2020 01 13;285:113273. Epub 2019 Sep 13.

Department of Population Health & Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616, USA. Electronic address:

There exists a surprising diversity in the physiology and endocrinology of pregnancy among mammals in both the source (luteal/placental) and metabolism of progesterone. To evaluate the possible diversity of steroid metabolism within toothed cetaceans, we investigated 5α-reduced progesterone metabolites and androgens in cyclic (luteal phase) and pregnant captive killer whales, belugas and bottlenose dolphins (n = 5/species) bled longitudinally in early, mid- and late pregnancy (0.16, 0.50 and 0.85 fractions of 535, 464 and 380 gestation days, respectively). Mid-luteal samples were also collected. Serum was analyzed by liquid chromatography tandem-mass spectrometry as previously validated for (among others) progesterone, 20αOH-progesterone (20αOHP), 5α-dihydroprogesterone (DHP), several additional 5α-reduced metabolites and androgens (dehydroepiandrosterone, androstenedione and testosterone). The predominant mid-luteal pregnanes were: progesterone, belugas; progesterone and 20αOHP, dolphins; allopregnanolone (3α-DHP) and progesterone, killer whales. Progesterone was 2-4-fold higher in early pregnancy than mid-luteal samples but decreased thereafter. The predominant metabolite, 3β,20α-dihydroprogesterone (3β,20α-DHP; 40-80 ng/ml) was higher in mid- and late-than early gestation in all 3 species. Concentrations of 20αOHP and 3β,20α-DHP were similar at mid-gestation but 20αOHP declined in late-gestation in killer whales, and 20αOHP was lower than 3β,20α-DHP in belugas and dolphins throughout gestation. Other 5α-reduced metabolites, DHP, 3α-DHP and 20α-DHP, were far lower throughout pregnancy (<10 ng/ml). DHP and 3α-DHP decreased from early to mid-gestation in belugas, but changed little in killer whales and dolphins. These data suggest that progesterone metabolism is relatively conserved among these cetacean species. As in equine pregnancies, 3β,20α-DHP is the major metabolite, increasing at the expense of progesterone as pregnancy progresses. Androstenedione and testosterone also increased detectably in mid- to late-gestation in these species. The tissue source remains unknown, but progesterone metabolism during gestation in these cetaceans is similar to horses and, together with androgens, may be reliable biomarkers of pregnancy.
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http://dx.doi.org/10.1016/j.ygcen.2019.113273DOI Listing
January 2020

Hematologic and Biochemical Reference Interval Development and the Effect of Age, Sex, Season, and Location on Hematologic Analyte Concentrations in Critically Endangered Yangtze Finless Porpoise ( ssp. ).

Front Physiol 2019 11;10:792. Epub 2019 Jul 11.

Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.

In this study, references intervals for 49 clinicopathological parameters were established for the critically endangered Yangtze finless porpoise (YFP) (). Both from the wild (Poyang Lake) and seminatural (Tian-E-Zhou Oxbow) populations, individual blood samples from 188 animals were collected from 2009 to 2017 and from 2002 to 2015, respectively. For reference interval determination, we used a non-parametric bootstrap-based procedure to determine the 95th percentiles and the associated 90% confidence interval for each analyte. Our results indicated a need to partition the analyte concentrations by sex, age group, or pregnancy; however, we did not find a need to partition results by location. We then used a linear mixed model to determine if evidence existed for mean differences between location with sex and season as covariates and age group as the clustered random variable on mean hematological parameters in the YFP. We found that 88% of the analytes were significantly different between locations. Within the covariates, sex and season showed 31 and 69% significant difference in mean distributions, respectively. Additionally, age group provided a significant source of variation in 25% of the analytes. In summary, our finding suggests that analytes should be grouped according to sex, age, and reproductive status (non-pregnant and non-lactating, pregnant and lactating). Furthermore, we have provided the first set of reference intervals for 49 clinicopathological parameters that could provide guidelines for the initial evaluation of individuals during health assessments.
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http://dx.doi.org/10.3389/fphys.2019.00792DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6637261PMC
July 2019

Sperm handling in aquatic animals for artificial reproduction.

Theriogenology 2019 Jul 2;133:161-178. Epub 2019 May 2.

CCMAR, University of Algarve, Campus of Gambelas, 8005-139 Faro, Portugal.

Artificial reproduction involves collection and handling of gametes in a way that secures their quality and maximizes the fertilization outcome. In addition to initial sperm quality, numerous steps can affect the final result of fertilization, from the sperm collection process until gamete mixing (or co-incubation) when the spermatozoon enters or fuses with the oocyte. In this review, we summarize the whole process of sperm handling, from collection until fertilization for fish, penaeid shrimp, bivalve mollusks and marine mammals. To obtain sperm from captive animals, techniques vary widely across taxa, and include stripping by abdominal massage or testis surgical removal in fish, spermatophore collection in penaeid shrimps, gonadal scarification or temperature shock in bivalve mollusks, and voluntary collection via positive reinforcement in mammals. In most cases, special care is needed to avoid contamination by mucus, seawater, urine, or feces that can either activate sperm motility and/or decrease its quality. We also review techniques and extender solutions used for refrigerated storage of sperm across the aforementioned taxa. Finally, we give an overview of the different protocols for in vivo and in vitro fertilization including activation of sperm motility and methods for gamete co-incubation. The present study provides valuable information regarding breeder management either for animal production or species conservation.
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http://dx.doi.org/10.1016/j.theriogenology.2019.05.004DOI Listing
July 2019

Effect of age, sex, and season on the variation in blood analytes of a clinically normal ex situ population of killer whales (Orcinus orca).

Vet Clin Pathol 2019 Mar 24;48(1):100-113. Epub 2019 Jan 24.

Veterinary Services, SeaWorld San Diego, San Diego, California.

Background: The effects of sex, age, and season on blood analyte concentrations have not been investigated for the killer whale (Orcinus orca). Defining these changes provides background data for improving the care of managed populations and defines normal changes that could occur in wild counterparts.

Objectives: We aimed to define hematologic and serum biochemical variation by age, sex, and season for an ex situ killer whale population.

Methods: Blood samples collected from killer whales during normal wellness exams were retrospectively identified. Killer whales were categorized by age; calf (0-2.9 years), juvenile (3-10.9 years), early adult (11-20.9 years), adult (21-30.9 years), and aged (>30.9 years); sex; and season. Standard CBC and biochemistry were collated, and only samples without evidence of disease were used. A mixed effects maximum likelihood regression with animal identification (ID) as the random effects variable was used to compare groups with a significance set at P ≤ 0.01.

Results: All analytes differed by age, while only four differed by sex. Red blood cell parameters and associated renal analytes increased with age, while liver-associated analytes and glucose decreased. Season affected 59% of the blood analytes.

Conclusions: Aged killer whales showed strong evidence of altered physiology as compared with younger animals. Anemia did not develop with age as was observed in one bottlenose dolphin population. Observed decreases in renal function could be caused by chronic disease or dehydration. Decreases in immune function parameters suggest immune senescence. These results provide background data for evaluating the health of managed and free-ranging killer whales.
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http://dx.doi.org/10.1111/vcp.12697DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6850284PMC
March 2019

Physiological consequences of biologic state and habitat dynamics on the critically endangered Yangtze finless porpoises ( ssp. ) dwelling in the wild and semi-natural environment.

Conserv Physiol 2018 18;6(1):coy072. Epub 2018 Dec 18.

Institute of Hydrobiology, the Chinese Academy of Sciences, Wuhan, Hubei Province, People's Republic of China.

The objectives of this study were to investigate the effects of habitat and biological state on the physiology of critically endangered wild and semi-natural Yangtze Finless Porpoises (YFPs; ssp. ) by measuring and comparing serum biochemical parameters. A total of 168 YFPs were sampled, 68 living in the semi-natural (Tian-E-Zhou Oxbow) and 98 living in the wild (Poyang Lake, PL) environment. The YFPs in the Tian-E-Zhou Oxbow were sampled from 2002 to 2015 and in the PL from 2009 to 2017. Each population was divided into Juvenile Male, Juvenile Female, Adult Male, Pregnant and Lactating Female life history categories. Overall, with location, 19/33 of the analytes and with season 18/33 of the analytes were significantly different. Similarly, within each location, 15/33 of the analytes changed with time in PL while only 8/33 changed with time in Tian-E-Zhou Oxbow, respectively. Finally, 15/33 of the analytes demonstrated significant differences between the different age and sex groups of animals. In our study, a significant variation, as well as an increasing and decreasing pattern of several parameters in both populations, suggest a worsening ecological environment of both habitats. This study will help in health assessment, improving conservation and management practices, a crucial requisite for biodiversity conservation.
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http://dx.doi.org/10.1093/conphys/coy072DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6298535PMC
December 2018

SERUM COBALAMIN AND FOLATE CONCENTRATIONS AS INDICATORS OF GASTROINTESTINAL DISEASE IN KILLER WHALES ( ORCINUS ORCA).

J Zoo Wildl Med 2018 Sep;49(3):564-572

Cobalamin and folate are water-soluble vitamins that are useful indicators of chronic gastrointestinal (GI) function in humans and some animal species. Serum cobalamin and folate concentrations in an ex situ population of killer whales ( Orcinus orca) were measured and factors that may affect their serum concentrations were identified. Serum samples ( n = 104) were analyzed from killer whales ( n = 10) both while clinically healthy and during periods of clinical GI disease as defined by clinical signs and fecal cytology. To characterize serum cobalamin and folate concentrations in clinically healthy animals, a mixed-model regression was used, with cobalamin and folate both significantly affected by weight (cobalamin: P < 0.0001, folate: P = 0.006) and season (cobalamin: P < 0.0001, folate: P < 0.0001). The marginal mean concentrations for cobalamin and folate across weight and season were 742 ± 53.6 ng/L and 30.2 ± 2.6 μg/L, respectively. The predicted 95% confidence intervals (CI) for these analytes were then compared with samples collected during periods of GI disease. Across individuals, 22% (2/9) of the folate and 80% (8/10) of the cobalamin samples from the animals with GI disease fell outside the 95% CI for the population. When comparing samples within an individual, a similar pattern presented, with 100% of cobalamin of the observed abnormal samples reduced compared to healthy animal concentration variability. The same was not true for folate. These results suggest that serum concentrations of cobalamin and folate may be useful minimally invasive markers to identify GI disease in killer whales, especially when values are compared within an individual.
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http://dx.doi.org/10.1638/2017-0102.1DOI Listing
September 2018

Diagnostic assessment of reproductive status in white-spotted bamboo sharks (Chiloscyllium plagiosum).

Anim Reprod Sci 2018 Oct 9;197:48-57. Epub 2018 Aug 9.

SeaWorld and Busch Gardens Reproductive Research Center, 2595 Ingraham Rd, San Diego, CA, 92109, USA.

Relatively little is known about elasmobranch reproductive physiology compared to other species. An increased understanding of elasmobranch reproduction would improve the success of captive breeding and may aid in situ conservation efforts by reducing demand for wild-caught individuals. The reproductive status of seven adult female white-spotted bamboo sharks (Chiloscyllium plagiosum) (WSB) was monitored via coelomic ultrasonography and analysis of plasma biochemistry and steroid hormones over 6 months. Based on ultrasonic findings, females were categorized at each blood collection time point as: no follicular activity (INACTIVE), follicles but no eggs present (ACTIVE-OVARY), and eggs present within the oviduct (ACTIVE-OVIDUCT). Triglyceride concentrations were greater for those with the ACTIVE-OVARY (75.98 mg/dL; CI 61.81-90.15 mg/dL) and ACTIVE-OVIDUCT (87.0 mg/dL; CI 70.20 to 103.81 mg/dL) categories than INACTIVE (51.81 mg/dL; CI 37.07-66.54 mg/dL) category. No significant differences were observed for PCV, total solids, calcium, phosphorus, iron or progesterone. Estradiol concentrations were less for the INACTIVE (0.15 ng/ml; CI 0.08 to 0.25 ng/ml) than ACTIVE-OVARY (0.63 ng/ml; CI 0.42 to 0.88 ng/ml) and ACTIVE-OVIDUCT (0.92 ng/ml; CI 0.64-1.26 ng/ml) category. Testosterone concentrations differed among reproductive states, being greater with the INACTIVE (0.22 ng/ml; CI 0.13 to 0.37 ng/ml) and peaking in the ACTIVE-OVIDUCT (2.12 ng/ml; CI 1.25-3.60 ng/ml) state. The ultrasonic technique was performed in a standardized manner, and the anatomy was validated via opportunistic post-mortem examinations and MRI. Using the described diagnostic techniques, reproductive status in WSB can be routinely monitored, and findings have implications for improving the success of captive breeding efforts in other elasmobranch species.
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http://dx.doi.org/10.1016/j.anireprosci.2018.08.005DOI Listing
October 2018

Longitudinal profiles of relaxin and progestagens during pregnancy, pregnancy loss and false pregnancy in the killer whale (Orcinus orca).

Gen Comp Endocrinol 2018 10 18;267:98-108. Epub 2018 Jun 18.

SeaWorld and Busch Gardens Reproductive Research Center, San Diego, CA 92109, United States.

The circulating pattern of immunoreactive relaxin and progestagens based on monthly and gestational stage (early, mid, late) profiles were determined during pregnancies that resulted in live calves (LIVE, n = 30), stillbirths (STILLB, n = 3), abortions (ABORT, n = 5) and presumptive false pregnancies (FALSE, n = 8), and during the follicular (n = 34) and luteal phase (n = 58). Monthly LIVE relaxin concentrations steadily increased during gestation, but values did not significantly exceed those of the luteal phase until 9 months prior to parturition, peaking during the final month at 2356 ng/ml. Relaxin surged (P < 0.05) during the final week of gestation (36,397 ng/ml), undergoing a 3 and 9-fold increase compared with concentrations in the preceding two weeks, respectively. Monthly relaxin production did not differ among each reproductive state with the exception of months-13-16 where concentrations were higher (P < 0.001) for STILLB than LIVE. Relaxin concentration was reduced (P < 0.0001) by 849% in placental versus maternal serum collected within 1 day of labor. Mid- and late-pregnancy progestagen concentrations were lower for FALSE (P < 0.001) compared with STILLB and LIVE. Late pregnancy progestagen concentrations were reduced for FALSE (P < 0.05) and ABORT (P < 0.02) compared with LIVE and STILLB. Monthly progestagen production in ABORT tended to be lower than LIVE across a range of gestational months (Months 2, 7, 8, 11) but this difference only became significant during months 14 and 15. Results indicate that relaxin is primarily produced by the CL during pregnancy, and that concentrations could not be used to differentiate from non-pregnant females until the final 6 months of gestation. In addition, as would be expected from a primarily CL product, relaxin cannot be used to detect abnormal pregnancies. Conversely, progestagens, which are produced by both the placenta and CL can be used to differentiate FALSE from normal pregnancy and may be useful indicators of fetal health in the killer whale.
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http://dx.doi.org/10.1016/j.ygcen.2018.06.008DOI Listing
October 2018

PRELIMINARY EVALUATION OF SEMINAL PLASMA PROTEINS AND IMMUNOREACTIVITY OF NERVE GROWTH FACTOR AS INDICATIVE OF AN OVULATION INDUCING FACTOR IN ODONTOCETES.

J Zoo Biol 2018 ;2(1):21-29

SeaWorld and Busch Gardens Species Preservation Laboratory, San Diego, United States.

In the seminal plasma of terrestrial mammalian species known as induced (e.g., camels) and spontaneous (e.g., cattle) ovulators, an ovulation-inducing factor (OIF) with a protein structure similar to beta-nerve growth factor (β-NGF) has been identified. Detection of an OIF/NGF in the seminal plasma of cetaceans would have both basic and applied implications in reproductive biology and conservation management programs. A preliminary evaluation was conducted to characterize the distribution and abundance of seminal plasma proteins in aquarium-based belugas and a Pacific white-sided and bottlenose dolphin. Initially, SDS-PAGE was used with 50 μg of total protein for separation; thereafter, Western immunoblot was used with anti-NGF. In addition to odontocete seminal plasma, a purified fraction of llama seminal plasma (100 ng protein) and an extract of mouse brain (20 μg total protein) were included as positive controls for NGF. Within the two belugas, visual inspection of the protein bands indicated similar distribution and intensity. However, among the belugas and Pacific white-sided and bottlenose dolphins there was more diversity than similarity in the distribution and abundance of seminal plasma proteins. While immunoreactivity of NGF was distinctly evident in the llama and mouse positive controls, there was no visual reactivity in any of the odontocete samples. These preliminary results provide novel information indicating more homogeneity within and heterogeneity among seminal plasma proteins of ondentocetes. Although NGF was not immunologically detected, future studies are required to address the apparent limitations of immuno-detection of NGF, especially if the post-translational form of β-NGF is in low abundance in the seminal plasma of belugas and Pacific white-sided and bottlenose dolphins.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6889870PMC
January 2018

Characterization and longitudinal monitoring of serum androgens and glucocorticoids during normal pregnancy in the killer whale (Orcinus orca).

Gen Comp Endocrinol 2017 06 23;247:116-129. Epub 2017 Jan 23.

SeaWorld Parks and Entertainment, Inc., SeaWorld and Busch Gardens Reproductive Research Center, San Diego, CA 92109, USA.

The secretory patterns of testosterone (T), androstenedione (A4), dehydroepiandrosterone (DHEA), cortisol (C), and corticosterone (Co) were characterized throughout 28 normal pregnancies until two-months post-partum in eleven killer whales. Effects of fetal sex, dam parity or age, and season were evaluated across either day post-conception (DPC), stage of pregnancy (PRE, EARLY, MID, LATE, POST) or indexed month post-conception (IMPC) using a mixed model linear regression with animal ID and pregnancy number as the random variables. Across DPC, DHEA, A4 and T concentrations were affected (P<0.05) by season, with highest concentrations during spring (DHEA, A4, & T) and summer (A4) as compared to the fall. A significant effect of parity on androgen production was observed only for DHEA, with multiparous females having higher (P=0.01) concentrations than nulliparous females. All three androgens significantly increased with each successive pregnancy stage and IMPC with peak concentrations occurring during IMPC 10 (DHEA), 13 (A4) and 14 (T), respectively. Cortisol was affected by season (P=0.03) with highest concentrations being detected during the months of fall, while Co was only affected by parity (P=0.003) with significant increases observed for primiparous females as compared to nulliparous females. Cortisol and Co concentrations peaked (P<0.05) during IMPC 17 (i.e., the month prior to parturition). The C to Co ratio during pregnancy was 7.4 to 1, indicating that cortisol is the major circulating glucocorticoid studied to date in pregnant killer whales. The significant increase in concentrations of maternal androgens throughout pregnancy, which were unrelated to fetal sex, indicates that they play an important role during killer whale fetal development.
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http://dx.doi.org/10.1016/j.ygcen.2017.01.023DOI Listing
June 2017

Testosterone and progesterone concentrations in blow samples are biologically relevant in belugas (Delphinapterus leucas).

Gen Comp Endocrinol 2017 05 16;246:183-193. Epub 2016 Dec 16.

University of Rhode Island, 120 Flagg Rd, Kingston, RI 02881, USA.

Steroid hormone analysis in blow (respiratory vapor) may provide a minimally invasive way to assess the reproductive status of wild cetaceans. Biological validation of the method is needed to allow for the interpretation of hormone measurements in blow samples. Utilizing samples collected from trained belugas (Delphinapterus leucas, n=20), enzyme immunoassays for testosterone and progesterone were validated for use with beluga blow samples. Testosterone concentrations in 40 matched blood and blow samples collected from 4 male belugas demonstrated a positive correlation (R=0.52, p<0.0001). Progesterone concentrations in 64 matching blood and blow samples from 11 females were also positively correlated (R=0.60, p<0.0001). Testosterone concentrations (mean±SD) in blow samples collected from adult males (119.3±14.2pg/ml) were higher (p<0.01) than that of a juvenile male (<8years) (59.4±6.5pg/ml) or female belugas (54.1±25.7pg/ml). Among adult males, testosterone concentrations in blow demonstrated a seasonal pattern of secretion, with peak secretion occurring during the breeding season (February-April, 136.95±33.8pg/ml). Progesterone concentrations in blow varied by reproductive status; pregnant females (410.6±87.8pg/ml) and females in the luteal phase of the estrous cycle (339.5±51.0pg/ml) had higher (p<0.0001) blow progesterone concentrations than non-pregnant females without a corpus luteum (242.5±27.3pg/ml). Results indicate that blow sample analysis can be used to detect variation in reproductive states associated with large differences in circulating testosterone or progesterone in belugas.
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http://dx.doi.org/10.1016/j.ygcen.2016.12.006DOI Listing
May 2017

Evaluation of anti-Erysipelothrix rhusiopathiae IgG response in bottlenose dolphins Tursiops truncatus to a commercial pig vaccine.

Dis Aquat Organ 2016 10;121(3):249-256

Veterinary Services Department, SeaWorld of San Diego, 500 SeaWorld Drive, San Diego, CA 92109, USA.

Erysipelothrix rhusiopathiae is the causative agent of erysipeloid in humans and of erysipelas in various animals, including bottlenose dolphins Tursiops truncatus, in which an infection has the potential to cause peracute septicemia and death. The purpose of this study was to evaluate the efficacy of using an off-label porcine (ER BAC PLUS®, Zoetis) E. rhusiopathiae bactrin in a bottlenose dolphin vaccination program by determining the anti-E. rhusiopathiae antibody levels in vaccinated dolphins over a 10 yr period. Serum samples (n = 88) were analyzed using a modified fluorescent microbead immunoassay from 54 dolphins, including 3 individuals with no history of vaccination and 51 dolphins with an average of 5 vaccinations, 3 of which had previously recovered from a natural E. rhusiopathiae infection. A mean 311-fold increase in the immunoglobulin G (IgG) antibody index was measured in a subsample of 10 dolphins 14 d after the first booster vaccination. Serum IgG antibody titers were influenced by number of vaccines received (r2 = 0.47, p < 0.05) but not by age, gender, history of natural infection, adverse vaccine reaction, vaccination interval or time since last vaccination. The commercial pig bacterin was deemed effective in generating humoral immunity against E. rhusiopathiae in dolphins. However, since the probability of an adverse reaction toward the vaccine was moderately correlated (p = 0.07, r2 = 0.1) with number of vaccines administered, more research is needed to determine the optimal vaccination interval.
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http://dx.doi.org/10.3354/dao03061DOI Listing
October 2016

Circulating anti-Müllerian hormone concentrations in relation to age and season in male and female beluga (Delphinapterus leucas).

Reprod Fertil Dev 2017 Aug;29(8):1642-1652

SeaWorld Parks and Entertainment, Inc., SeaWorld and Busch Gardens Reproductive Research Center, 2595 Ingraham Street, San Diego, CA 92109, USA.

The present study aimed to describe serum anti-Müllerian hormone (AMH) patterns of ex situ male and female beluga to examine the influence of age (divided into 5-year categories) or sexual maturation and reproductive season. In males aged 5-9 years, AMH concentrations were significantly (P<0.05) higher than those in all age categories exceeding 15 years and were not influenced by season (P=0.57). AMH concentrations in females peaked in the 5-9-year age category during the breeding season and decreased (P<0.05) after 9 years of age. Aged females displayed lower (P<0.05) AMH concentrations than immature and mature animals and immature females secreted higher concentrations than mature animals (P=0.03). For mature females, seasonal differences (P=0.02) in AMH concentrations were detected, with females in the breeding season displaying higher AMH concentrations than in the non-breeding season. This is the first time AMH has been characterised in a cetacean species and the first potential hormonal evidence of reproductive senescence in beluga. Further research is required to determine if this hormone can be used as a predictor of fertility for the species.
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http://dx.doi.org/10.1071/RD15537DOI Listing
August 2017

Characterization and longitudinal monitoring of serum progestagens and estrogens during normal pregnancy in the killer whale (Orcinus orca).

Gen Comp Endocrinol 2016 09 9;236:83-97. Epub 2016 Jul 9.

SeaWorld Parks and Entertainment, Inc., SeaWorld and Busch Gardens Reproductive Research Center, San Diego, CA 92109, USA.

The secretory patterns of progestagens and estrogens were characterized throughout 28 normal pregnancies until two month post-partum in eleven killer whales. HPLC analysis of serum from different reproductive stages (luteal phase, EARLY, MID, and LATE pregnancy) identified three major immunoreactive progestagen peaks; progesterone (P4), 5α-pregnane-3,20-dione (5α-DHP) and pregnanediol, with 5α-DHP approximately half of that for P4 in the luteal phase, and EARLY, but approximately 2/3 of P4 during MID and LATE pregnancy. At birth, 5α-DHP was the only significant (>10% immunoreactivity) immunoreactive progestagen detected in placental (umbilical cord) serum. Maternal recognition of pregnancy appears to occur between day 21 and 28 post-ovulation when a significant deviation in progestagen concentrations between conceptive and non-conceptive cycles was detected. Progestagen concentrations during pregnancy displayed a bimodal pattern with significant peaks (P<0.05) in EARLY (indexed month post-conception [IMPC] 2, 3, 4) and MID (IMPC 9, 10) before decreasing (P<0.05) over an 11day interval to luteal phase concentrations on the day of parturition. Among estrogens, estriol was secreted in the highest concentrations but only estrone (free and conjugated) and estradiol increased (P<0.001) during pregnancy, with peaks observed during the final month of gestation, and an influence (P<0.05) of fetal sex on estradiol production was detected. Collective findings indicate that P4 derived from the corpus luteum is the major biologically active progestagen during the luteal phase and pregnancy, and that 5α-DHP production, possibly from both luteal and placental sources, increases during the second half of pregnancy.
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http://dx.doi.org/10.1016/j.ygcen.2016.07.010DOI Listing
September 2016

Chicks produced in the Magellanic penguin (Spheniscus magellanicus) after cloacal insemination of frozen-thawed semen.

Zoo Biol 2016 Jul 8;35(4):326-38. Epub 2016 Jun 8.

SeaWorld and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment, San Diego, California.

The in vitro and in vivo functionality of cryopreserved spermatozoa was examined over two breeding seasons in a zoological colony of Magellanic penguins (Spheniscus magellanicus). Frozen-thawed semen was inseminated into five anesthetized females, over a total of eight egg production cycles, with a different male used for each artificial insemination (AI) within each season. Females were maintained within the colony in cordoned nest sites to prevent copulation with their paired male, and were inseminated every 3-10 days until the first oviposition. Semen frozen from seven males using a straw method retained 39.8%, 25.7%, 74.0%, and 52.1% of its initial total motility, progressive motility, average path velocity, and plasma membrane integrity, respectively. Normal morphology of motile cells was reduced (P < 0.05) during freeze-thawing from 76.7% immediately prior to freezing to 65.3% post-thawing. Conceptive females received 1.6 ± 0.2 inseminations before the first oviposition, with 19.2 ± 1.6 × 10(6) motile, morphologically normal spermatozoa per insemination. Overall fertility was 53.3% (8/15 eggs), hatchability was 50.0% (4/8), and genetic analyses confirmed that all embryos and hatchlings were sired by the AI male. Fertile eggs were laid at 4.0-12.1 days after AI, indicating that frozen-thawed spermatozoa resided in the female reproductive tract for up to ∼7.2 days prior to fertilization. Results demonstrate that frozen-thawed Magellanic penguin spermatozoa are fully functional in vivo and support the use of genome banking and AI as tools for managing the sustainability of zoological penguin populations. Zoo Biol. 35:326-338, 2016. © 2016 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/zoo.21304DOI Listing
July 2016

Survivorship pattern inaccuracies and inappropriate anthropomorphism in scholarly pursuits of killer whale ( ) life history: a response to Franks et al. (2016).

J Mammal 2016 Jun 8;97(3):899-905. Epub 2016 Mar 8.

SeaWorld and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment , 2595 Ingraham Road, San Diego, CA 92019 , USA (TRR, JKO).

Franks et al. (2016) consider that the degree of error in estimated ages used to define survivorship patterns of northern and southern resident killer whale ( ) populations is of insignificant impact to estimates of the species' postreproductive lifespan (PRLS). We provide evidence that survival probabilities for killer whales using a dataset comprising estimated age animals differ significantly from that determined using data collected from known-age animals in the Pacific Northwest over the past 40 years. Consequently, our findings indicate that the degree of error in age estimates and ensuing survivorship patterns do not support the notion by Franks et al. (2016) of a prolonged PRLS in the female killer whale that is comparable to the PRLS observed in humans.
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http://dx.doi.org/10.1093/jmammal/gyw023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6377038PMC
June 2016

MALE REPRODUCTIVE PHYSIOLOGY AND THE DEVELOPMENT OF ARTIFICIAL INSEMINATION IN THE MAGELLANIC PENGUIN (SPHENISCUS MAGELLANICUS) USING CHILLED-STORED SEMEN.

J Zoo Wildl Med 2016 Mar;47(1):206-22

Research was performed to increase our understanding of male Magellanic penguin (Spheniscus magellanicus) reproductive biology and to develop artificial insemination (AI) technology to assist with maintaining the species' genetic diversity. Seminal traits were characterized from seven males with noncontaminated ejaculates (n = 123) displaying high in vitro motion parameters, membrane integrity, and morphology. Seven females were maintained in nest sites that permitted visual, auditory, and tactile contact with their paired male but not copulation for 18.3 ± 2.4 days before egg lay. After cloacal AI (2.6 ± 0.4 inseminations/female) with semen chilled for up to 20.5 hr at 5°C, all females produced one to two fertile eggs, with the first oviposition occurring within 7 days of plasma progesterone concentrations exceeding 0.8 ng/ml. Overall fertility was 91.7%, hatchability was 63.6%, and genetic analyses confirmed that all embryos and hatchlings were sired by AI males. The heterospermic AI design demonstrated that eggs were fertilized by spermatozoa chilled for 1.5-19.8 hr before AI and were laid 4.5-11.5 days post AI. These results contribute new data on Magellanic penguin sperm biology and demonstrate that high fertility rates after AI of chilled semen can be achieved with females remaining in proximity to their paired mate.
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http://dx.doi.org/10.1638/2015-0209.1DOI Listing
March 2016

Comparisons of life-history parameters between free-ranging and captive killer whale () populations for application toward species management.

J Mammal 2015 Sep 11;96(5):1055-1070. Epub 2015 Jul 11.

SeaWorld and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment , 2595 Ingraham Road, San Diego, CA 92019 , USA (TRR, JKO).

Data collected on life-history parameters of known-age animals from the northern (NR) and southern resident (SR) killer whales () of the eastern North Pacific were compared with life-history traits of killer whales located at SeaWorld (SEA) facilities. For captive-born SEA animals, mean age and body length at 1st estrus was 7.5 years and 483.7cm, respectively. Estimated mean age at 1st conception was different ( < 0.001) for the combined data from both northern and southern resident (NSR) free-ranging populations (12.1 years) compared to SEA (9.8 years), as was the estimated mean age at 1st observed calf (SEA: 11.1 years, NSR: 14.2 years, < 0.001). Average calf survival rate to 2 years of age for SEA animals (0.966) was significantly greater ( = 0.04) than that for SR (0.799). Annual survival rate (ASR) for SEA increased over approximately 15-year increments with rates in the most recent period (2000-2015 ASR: 0.976) improved ( < 0.05) over the first 2 periods of captivity (1965-1985: 0.906; 1985-2000: 0.941). The SR (0.966) and NR ASR (0.977) were higher ( ≤ 0.05) than that of SEA until 2000, after which there were no inter-population differences. Based on ASR, median and average life expectancy were 28.8 and 41.6 years (SEA: 2000-2015), 20.1 and 29.0 years (SR), and 29.3 and 42.3 years (NR), respectively. The ASR for animals born at SEA (0.979) was higher ( = 0.02) than that of wild-caught SEA animals (0.944) with a median and average life expectancy of 33.1 and 47.7 years, respectively. These data present evidence for similar life-history parameters of free-ranging and captive killer whale populations and the reproductive potential and survivorship patterns established herein have application for use in future research concerning the overall health of both populations.
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http://dx.doi.org/10.1093/jmammal/gyv113DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4668992PMC
September 2015

Relaxin as a hormonal aid to evaluate pregnancy and pregnancy loss in bottlenose dolphins (Tursiops truncatus).

Gen Comp Endocrinol 2017 02 24;242:24-29. Epub 2015 Dec 24.

SeaWorld and Busch Gardens Reproductive Research Center, San Diego, CA 92109, United States. Electronic address:

This study was conducted to critically evaluate weekly and monthly circulating concentrations of immunoreactive relaxin throughout pregnancies that resulted in live births, stillbirths, and abortions in aquarium-based bottlenose dolphins. A relaxin RIA was used to analyze serum collected during 74 pregnancies involving 41 dolphins and 8 estrous cycles as well as 8 non-pregnant dolphins. Pregnancies resulted in live births (n=60), stillbirths (n=7), or abortions (n=7). Relative to parturition (Month 0), monthly changes (P<0.0001) in relaxin was indicated by relatively low concentrations during early pregnancy (Months -12 to -9) which subsequently increased (P<0.05) during mid- (Months -8 to -5) to late (Months -4 to -1) pregnancy; relaxin was highest (P<0.05) at the time of parturition. Post-parturition (Month 1), concentrations decreased (P<0.05). During the first 4weeks post-ovulation, relaxin concentrations were not different between pregnant and non-pregnant dolphins (status-by-week interaction, P=0.59). Status-by-month interaction (P<0.0002) involving different pregnancy outcomes was due, impart, to an increase in relaxin during early pregnancy (P<0.05) that was comparable among dolphins with live births, stillbirths, and abortions except concentrations were lower (P<0.05; 52%) at mid-pregnancy in association with pregnancy loss. Thereafter, concentrations increased (P<0.05) during late pregnancy in dolphins with stillbirths but not in dolphins with abortions. In conclusion, this study provided new information on the pregnancy-specific nature of relaxin, critical evaluation of the fundamental characteristics of relaxin during pregnancy and pregnancy loss, and clarification on the strengths and limitations of relaxin as a diagnostic aid to determine pregnancy status and assess maternal-fetal health in bottlenose dolphins.
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http://dx.doi.org/10.1016/j.ygcen.2015.12.024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4919223PMC
February 2017

Characterization of estrogens, testosterone, and cortisol in normal bottlenose dolphin (Tursiops truncatus) pregnancy.

Gen Comp Endocrinol 2016 Jan 21;226:102-12. Epub 2015 Dec 21.

SeaWorld Parks and Entertainment, Inc., SeaWorld and Busch Gardens Reproductive Research Center, San Diego, CA 92109, USA.

The goal of this study was to describe profiles of serum estrogens, testosterone and cortisol during normal pregnancy in bottlenose dolphins. Predominant estrogens in all categories of dolphin sera pools during estrus and pregnancy (EARLY: Days 0-120; MID: Days 121-240; LATE: Days 241 to parturition; Day 0=day of conception) were estrone/estrone conjugates (E1-C) and estriol (E3). Serum samples collected throughout 101 normal pregnancies were analyzed for E1-C, E3, testosterone (T) and cortisol (CORT). E1-C was higher (P<0.05) during LATE compared to EARLY and MID, and higher (P<0.05) in nulliparous than multiparous females. E1-C concentrations were also inversely associated with maternal age (P=0.05). E3 was higher (P<0.05) in EARLY than MID and LATE, and higher overall for nulliparous than multiparous females, but concentrations were similar among gestational stages when parity was excluded from analyses. Analysis by indexed month post-conception (IMPC) demonstrated that E1-C increased from IMPC 9 and peaked at IMPC 11. E3 was significantly elevated during IMPC 1, decreased until IMPC 6 and peaked at IMPC 11. T increased (P<0.05) at IMPC 3 and continued to increase throughout gestation (P<0.05). CORT was higher (P<0.05) during LATE compared to EARLY and MID (P<0.05), peaked during IMPC 12, and was not affected by parity. Hormone profiles were not influenced by fetal sex.
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http://dx.doi.org/10.1016/j.ygcen.2015.12.019DOI Listing
January 2016

Semen characterization, seasonality of production, and in vitro sperm quality after chilled storage and cryopreservation in the king penguin (Aptenodytes patagonicus).

Zoo Biol 2014 Mar-Apr;33(2):99-109. Epub 2014 Jan 7.

SeaWorld and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment, San Diego, California.

Research was conducted to examine seasonal seminal traits and to establish short-term and long-term sperm preservation methods in the king penguin (Aptenodytes patagonicus) for use in genome banking and artificial insemination (AI). Spermic ejaculates (n = 87) obtained using a cooperative method were collected across multiple (n = 6, Male 1) and a single (Male 2) breeding season(s). Non-contaminated ejaculates (n = 69) were 0.36 ± 0.32 ml at 56.3 ± 62.7 × 10(7)  sperm/ml with 85.3 ± 10.6% total motility (TMot), 52.5 ± 12.9% progressive motility (PMot), 86.6 ± 24.3 µm/sec average path velocity (VAP) and 92.3 ± 3.7% plasma membrane intact. In vitro quality of chilled semen was best maintained over 48 hr at 5°C than 21°C, with decreased (P < 0.05) motility and morphology parameters observed by 24 and 6 hr, respectively. A comparison of two freezing methods (straw [STR] vs. directional [DF]) demonstrated similar effects on post-thaw quality at 0 and 3 hr, with the exception of plasma membrane integrity which was higher (P < 0.05) at 0 hr for DF (48.7 ± 6.5%) than STR (41.2 ± 7.0%). At 0 hr post-thaw, DF samples retained 46%, 69%, and 52% of their initial PMot, VAP, and plasma membrane integrity, respectively. Normal morphology of motile cells was reduced (P < 0.05) during freeze-thawing from 84% post-collection to 37% and 34% at 0 and 3 hr post-thaw, respectively. Results indicate that chilled and cryopreserved semen from the king penguin has potential for use in AI.
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http://dx.doi.org/10.1002/zoo.21111DOI Listing
August 2014

Hematological and serum biochemical analytes reflect physiological challenges during gestation and lactation in killer whales (Orcinus orca).

Zoo Biol 2013 Sep-Oct;32(5):497-509. Epub 2013 Jun 28.

SeaWorld and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment Corporation, San Diego, California.

Gestation and lactation result in metabolic alterations of the dam because of varying demands of the fetus and offspring during the different stages of development. Despite killer whales (Orcinus orca) having one of the longest gestations and highest birth weights of all mammals in human care, these metabolic alterations, and their impact on the physiology of the dam have not been measured. The objectives of this analysis were to determine if physiologic demands on the killer whale during pregnancy and lactation have measurable effects on hematology and biochemical analytes and if detectable, to compare these changes to those which are observed in other mammalian species. Forty hematologic and biochemical analytes from seven female killer whales (22 pregnancies, 1,507 samples) were compared between the following stages: (1) non-pregnant or lactating (control); (2) gestation; and (3) the first 12 months of lactation. Decreased hematocrit, hemoglobin, and red blood cell counts were indicative of plasma volume expansion during mid and late gestation. The killer whales exhibited a progressively increasing physiologic inflammatory state leading up to parturition. Gestation and lactation caused significant shifts in the serum lipid profiles. Gestation and lactation cause significant physiologic changes in the killer whale dam. The last 12 months of gestation had greater physiological impact than lactation, but changes associated with and immediately following parturition were the most dramatic. During this period, killer whales may experience increased susceptibility to illness, and anthropogenic and environmental disturbances.
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http://dx.doi.org/10.1002/zoo.21083DOI Listing
May 2014

Development and evaluation of deep intra-uterine artificial insemination using cryopreserved sexed spermatozoa in bottlenose dolphins (Tursiops truncatus).

Anim Reprod Sci 2013 Jun 19;139(1-4):168-81. Epub 2013 Apr 19.

SeaWorld and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment, San Diego, CA 92109, USA.

Since its development in bottlenose dolphins, widespread application of AI with sex-selected, frozen-thawed (FT) spermatozoa has been limited by the significant expense of the sorting process. Reducing the total number of progressively motile sperm (PMS) required for an AI would reduce the sorting cost. As such, this research compared the efficacy of small-dose deep uterine AI with sexed FT spermatozoa (SEXED-SMALL; ~50×10(6)PMS, n=20), to a moderate dose deposited mid-horn (SEXED-STD, ~200×10(6)PMS; n=20), and a large dose of FT non-sexed spermatozoa deposited in the uterine body (NONSEXED-LARGE, 660×10(6)PMS, n=9). Ten of the 11 calves resulting from use of sexed spermatozoa were of the predetermined sex. Similar rates of conception (NONSEXED-LARGE: 78%, SEXED-STD: 60%, SEXED-SMALL: 57%) and total pregnancy loss (TPL: NONSEXED-LARGE: 28.6%; SEXED-STD: 41.0%; SEXED-SMALL: 63.6%) were observed across groups, but early pregnancy loss (EPL,
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http://dx.doi.org/10.1016/j.anireprosci.2013.04.004DOI Listing
June 2013

Altrenogest and progesterone therapy during pregnancy in bottlenose dolphins (Tursiops truncatus) with progesterone insufficiency.

J Zoo Wildl Med 2012 Jun;43(2):296-308

From SeaWorld and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment Corporation, 2595 Ingraham Road, San Diego, California 92109, USA.

Progesterone production is essential for growth and development of the conceptus during pregnancy. Abnormal development of the corpus luteum (CL) after conception can result in early embryonic loss or fetal abortion. Routine monitoring of bottlenose dolphin (Tursiops truncatus) pregnancy after artificial insemination or natural conception with ultrasonography and serum progesterone determination has allowed for the establishment of expected fetal growth rates and hormone concentrations. Using these monitoring techniques, we revealed four pregnant dolphins (12-24 yr old) with abnormally low progesterone production indicative of luteal insufficiency. Once diagnosed, animals were placed on altrenogest (0.044-0.088 mg/kg once daily) alone or with oral progesterone (50-200 mg twice daily). Doses of hormone were increased or decreased in each animal based on how fetal skull biparietal and thoracic growth rates compared with published normal values. Hormones were withdrawn starting from day 358 of gestation in animals 1 and 2, with labor occurring 6 and 7 days after withdrawal and at 376 and 373 days of gestation, respectively. Both deliveries were dystocic, with each calf requiring manual extraction and fetotomy for calf 1. The fetuses in animals 3 and 4 died at 348 and 390 days of gestation, respectively. Induction of labor was attempted in both animals, after fetal death, by using a combination of rapid progesterone withdrawal and steroid and prostaglandin F2alpha administration. The calf of animal 4 had to be removed with manual cervical dilation and fetotomy All adult females survived the procedures. These data provide the first in vivo evidence that the CL is the primary source of progesterone throughout pregnancy in the bottlenose dolphin. Until further characterization of hormones required during pregnancy and at parturition has been accomplished, the exogenous progestagen supplementation protocol described here cannot be recommended for treatment of progesterone insufficiency in bottlenose dolphins.
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http://dx.doi.org/10.1638/2011-0166.1DOI Listing
June 2012
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