Todd Robeck - Academia.edu (original) (raw)

Papers by Todd Robeck

Aquatic Mammals, May 15, 2023

While the existence of human-animal relationships dates back thousands of years, the effects of t... more While the existence of human-animal relationships dates back thousands of years, the effects of these bonds on animal well-being have only recently been examined in detail. The existing literature demonstrates that factors such as familiar human caregivers and persistent, predictable care may, for example, lower an animal's fear response and improve overall welfare. The goal of the present study was to analyse how a range of variables, including age, sex, animal species, and previous bonds with a pet could influence the development of human-animal bonds between caregivers and animals at six affiliated zoological facilities. The present study is a survey of 201 animal caregivers focusing on their perception of the bonds shared between themselves and an animal with which they work and any experience with bonds they have with a companion animal at home. All respondents, regardless of the existence of a human-animal bond, also indicated their level of agreement with a series of general statements about human-animal relationships and their effects on animal management and welfare. The present study demonstrates that the type of animal species has a significant effect on the development of bonds between animals and their human caregivers, with a greater percentage of bonds developed between people and other mammalian species, and the smaller percentage of bonds between people and fish or reptiles. Personal identifiers, such as age, sex, or the number of years in the profession, did not have any significant correlation to bond development. In addition, having pets was also not a predictor of caregiver-animal bonds, though previous experiences with animal bonds did indicate a tendency to develop a bond. Overall, surveyed caregivers agreed with positive statements about human-animal relationships and their role in promoting better welfare for animals. Understanding the bonds shared by animal caregivers and the animals for which they are responsible is essential to fostering workplaces that consider the importance of the relationship between humans and animals, and the tangible benefits a positively perceived bond can have for both.

Behavior analysis in practice, Jul 20, 2022

Zoo Biology, Jun 28, 2013

Gestation and lactation result in metabolic alterations of the dam because of varying demands of ... more 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. Zoo Biol. XX:XX-XX, 2013.

Philosophical Transactions of the Royal Society B: Biological Sciences, 2021

Plasticity in the cardiac function of a marine mammal facilitates rapid adjustments to the contra... more 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 ( f H ) 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 f H 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 f H , breathing rate ( f R ) and body mass ( M b ), we measured simultaneous f H and f R in five cetacean species in human care. We found that a higher f R was associated with a higher mean instantaneous f H (i f H ) and minimum i f H of the RSA. By contrast, f H scaled inversely with M b such that larger animals had lower mean and minimum i f H s of the RSA. There was a significant allom...

CRC Press eBooks, Jun 27, 2001

Zoo Biology, 1993

To increase the basic understanding of killer whale (Orcinus orca) reproductive physiology necess... more To increase the basic understanding of killer whale (Orcinus orca) reproductive physiology necessary for the development of artificial breeding programs, we utilized radioimmunoassays (RIA) to detect urinary immunoreactive steroid metabolites (pregnanediol-3~-glucuronide [PdG] and estrone-conjugates [EC]) and gonadotropins (luteinizing hormone [LH] and follicle-stimulating hormone [FSH]) in urine samples from six female killer whales. Urine samples were collected from the whales by voluntary presentation behavior over a 2to 4-year period. All urinary hormone values were corrected for intersample urine concentration variations by indexing with creatinine. Daily urine samples from four whales were collected during two conceptions and 18 complete estrous cycles. LH, FSH, EC, and PdG immunoreactive levels were determined and combined with observed copulatory activity in five cycles, including two conceptive cycles from two whales. Mean luteal phase lengths ranged from 9.7 to 19.2 days. Mean follicular phase lengths ranged from 6.5 to 16.8 days. Mean estrous cycle lengths based on the first detectable PdG levels were 41.6 2 6.72 S.E.M. days. After PdG nadir, immunoreactive FSH levels showed a bimodal pattern with the first peak being greater in size, and both preceding a follicular phase EC increase. LH levels > the 95% confidence interval of the mean were considered significant.

International Journal of Andrology, Mar 28, 2013

Ejaculates from nine Asian and two African elephants were analysed to gain a further understandin... more Ejaculates from nine Asian and two African elephants were analysed to gain a further understanding of mechanisms underlying variable semen quality after transrectal massage. Semen analysis was performed after collection (0 h; subjective motility parameters only) and after 24 h of chilled storage at 10 °C (24 h; all ejaculate and sperm characteristics). Ejaculates with ≤50% total motility (TM) at 24 h, which represented &amp;amp;amp;gt;90% of collection attempts, contained a sperm population with a high degree of DNA damage (64.2 ± 19.2% fragmented DNA) and an elevated incidence of detached heads (43.3 ± 22.5%). In contrast, good quality ejaculates designated as those with &amp;amp;amp;gt;50% TM at 24 h displayed higher (p &amp;amp;amp;lt; 0.05) values of sperm kinetic parameters, DNA integrity and normal morphology. Fertility potential was high for good quality ejaculates from two males (one Asian and one African bull) based on in vitro characteristics after chilled storage for up to 48 h post-collection. Urine contamination of semen, as assessed quantitatively by creatinine concentration, was confirmed as a significant factor in reduced elephant ejaculate quality. However, the identification of considerable DNA damage and morphological degeneration in the majority of ejaculates after only 24 h of chilled storage indicates that sperm ageing could be a primary contributor to inconsistent semen quality in the elephant.

General and Comparative Endocrinology, Aug 1, 2020

Serum collected across the lifespan of four managed rhino species: black (Diceros bicornis, n = 1... more Serum collected across the lifespan of four managed rhino species: black (Diceros bicornis, n = 16), white (Ceratotherium simum simum, n = 19), greater one-horned (GOH, Rhinoceros unicornis, n = 11) and Sumatran (Dicerorhinus sumatrensis, n = 6) were validated and analyzed in an anti-Müllerian hormone (AMH) enzyme- linked immunoassay. Concentrations of AMH were examined over time, between sexes and throughout different reproductive states which included n = 3 female white rhinos immunocontracepted with porcine zona pellucida (pZP). Across species, males produced higher AMH concentrations compared to females. Among males, AMH concentrations varied by species aside from comparable values secreted between black and white rhinos. The GOH and Sumatran rhino secreted the highest and lowest male AMH concentrations, respectively. However, within each species, AMH concentrations were similar across male age categories. Preliminary insight into male AMH changes from birth to sexual maturity suggest its potential as a marker for onset of testicular maturation. Female black, GOH and Sumatran rhinos secreted comparable AMH concentrations which were higher than those in white rhino. Within each species, inter-individual variation in AMH secretion occurred among females of similar age. While AMH secretion did not differ across the ages sampled for female white (4->26 yr) and GOH (4-26 yr) rhinos, black and Sumatran rhinos > 26 and < 4 yr, respectively secreted lower AMH compared to conspecific females 7-26 yr of age. Two idiopathic infertility cases corresponded to low (outside species range) AMH values. The establishment of normative AMH concentrations in managed African and Asian rhinos provides an additional metric beyond traditional sex steroids to assess gonadal function. Further work is needed to determine if AMH can predict fertility potential in rhinos.

Reproduction, Fertility and Development, 2004

Most isolates of BVDV cause unapparent infections in cultured cells. Fetuses, postnatal animals o... more Most isolates of BVDV cause unapparent infections in cultured cells. Fetuses, postnatal animals or fetal bovine serum are possible sources of the virus for cultivated cells used as karyoplasts in cloning. Routine screening by veterinary diagnostic laboratories of 39 fetal fibroblast cell lines used in cloning research had revealed that 15 (39%) were positive for BVDV by various assays including RT-nPCR. As some were valuable transgenic cell lines, a rigorous protocol for evaluation of each line was undertaken to confirm infection with BVDV. A cryopreserved vial of each line was thawed, medium discarded and cells incubated (38.5 • C in 5% CO 2 and air) through 2 passages (6-10 days) in α-MEM supplemented with 10% equine serum. At the end of the second passage, cells were separated from medium, washed and assayed for presence of BVDV using virus isolation in 2 sequential passages in Madin Darby Bovine Kidney Cells and RT-nPCR. Available lots of fetal bovine serum and medium that had been used to culture the cells also were tested for BVDV. When the virus was detected, the RT-nPCR products were sequenced and compared. Also, an attempt was made to evaluate the earliest available cryopreserved passage of any positive cell lines. Results indicated that just 5 of 39 of the original cells tested (13%) were positive. Since cryopreserved earlier passages of 4 of the cell lines were available, they were assayed with the result that 2 of the 4 were not infected at the earliest passage. Further, BVDV was isolated from one lot of fetal bovine serum that was used to culture one of the cell lines. Sequence analysis verified that only 2 of these 4 cell lines were infected with the same isolate of BVDV, and one isolate was identical to the virus found in the fetal bovine serum used in medium to culture it. The discrepancy between our viral detection and that of the diagnostic laboratories is explained in part by the presumed test protocols. All BVDV-positive cells, as reported by the diagnostic laboratories, were positive by RT-nPCR. We presume that they did not separate medium from cells before assays. Thus, any noninfectious viral RNA that was in the medium (e.g. as would be expected in many lots of irradiated serum) would have been reported positive. The only possible sources for BVDV in these cell lines were the fetuses from which they originated or fetal bovine serum used in medium. Sequence analysis confirmed that serum was the source of viral infection in one line. The likely source of virus for 2 other lines was serum, since they were not infected at earlier passages. The 2 remaining cell lines were positive at the earliest available passages, so the fetuses from which cells were harvested could not be discounted as the source of BVDV. This report highlights the risks of introducing BVDV in embryo technologies and the difficulties that can be encountered in attempting accurate diagnosis of the presence of infectious virus.

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Theriogenology, May 1, 2009

ABSTRACT Efforts toward the conservation and captive breeding of wildlife can be enhanced by sper... more ABSTRACT Efforts toward the conservation and captive breeding of wildlife can be enhanced by sperm sorting and associated reproductive technologies such as sperm cryopreservation and artificial insemination (AI). Sex ratio management is of particular significance to species which naturally exist in female-dominated social groups. A bias of the sex ratio towards females of these species will greatly assist in maintaining socially cohesive groups and minimizing male–male aggression. Another application of this technology potentially exists for endangered species, as the preferential production of females can enable propagation of those species at a faster rate. The particular assisted reproductive technology (ART) used in conjunction with sperm sorting for the production of offspring is largely determined by the quality and quantity of spermatozoa following sorting and preservation processes. Regardless of the ART selected, breeding decisions involving sex-sorted spermatozoa should be made in conjunction with appropriate genetic management. Zoological-based research on reproductive physiology and assisted reproduction, including sperm sorting, is being conducted on numerous terrestrial and marine mammals. The wildlife species for which the technology has undergone the most advance is the bottlenose dolphin. AI using sex-sorted fresh or frozen-thawed spermatozoa has become a valuable tool for the genetic and reproductive management of captive bottlenose dolphins with six pre-sexed calves, all of the predetermined sex born to date.

Marine Mammal Science, Mar 11, 2016

Journal of Mammalogy, Mar 8, 2016

Franks et al. (2016) consider that the degree of error in estimated ages used to define survivors... more 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 (Orcinus orca) 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.

Theriogenology, Dec 1, 2010

The objective was to determine if seminal alkaline phosphatase (ALP) can serve as an indicator of... more The objective was to determine if seminal alkaline phosphatase (ALP) can serve as an indicator of true ejaculation in the rhinoceros. Concentrations of ALP activity were determined in seminal fractions collected from African black rhinos (Diceros bicornis), an African white rhino (Ceratotherium simum), and an Indian rhino (Rhinoceros unicornis) during electroejaculation. In addition, seminal fractions collected during penile massage of a Sumatran rhino (Dicerorhinus sumatrensis) were assessed. Correlations between ALP activity and sperm concentration, fraction pH, and fraction osmolality were evaluated in the Indian rhino and black rhino. Concentrations of ALP activity in rhino ejaculate fractions ranged from Ͻ 5 to 11,780 U/L and were positively correlated (P Ͻ 0.05) with sperm concentration for both Indian rhino (r ϭ 0.995) and black rhino (r ϭ 0.697), but did not exhibit a strong correlation with either pH or osmolality (P Ͼ 0.05). Data were insufficient for establishing meaningful correlation coefficients in the Sumatran rhino and white rhino, but preliminary results were in accordance with findings in the Indian rhino and black rhino. We concluded that ALP was present in rhinoceros semen, likely originated from the epididymides and/or testes, and could serve as a useful tool for assessing the production of ejaculatory versus pre-ejaculatory fluid in the rhinoceros.

Frontiers in Physiology, Jul 11, 2019

Nabi et al. Clinicopathological Reference Levels for YFPs sex, age, and reproductive status (non-... more Nabi et al. Clinicopathological Reference Levels for YFPs 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.

PubMed, Mar 1, 1998

Transabdominal ultrasonography and serum steroid concentrations were used to evaluate the effects... more Transabdominal ultrasonography and serum steroid concentrations were used to evaluate the effects of exogenous gonadotropin administration on ovarian activity of two anestrous bottlenose dolphins (Tursiops truncatus). The gonadotropin used for follicular recruitment was PG600, which has 400 IU equine chorionic gonadotropin (eCG) and 200 IU human chorionic gonadotropin (hCG) activity per 5 ml. Ovulation induction was attempted with hCG. PG600 was administered in two doses of 20 ml (1,600 IU eCG and 800 IU hCG) and 12.5 ml (1,000 IU eCG and 500 IU hCG), respectively, 48 hr apart on days 0 and 2. On day 6, 1,500 IU of hCG was administered. Progesterone and total immunoreactive estrogens were determined before and after the gonadotropin administration. Bilateral ovarian ultrasonographic exams were performed daily on days 4-9 and on day 22. Serum immunoreactive estrogen concentrations were greater than the pretreatment concentrations after day 4 for both dolphins and remained elevated for the rest of the study. Serum progesterone concentrations rose above 1 ng/ml 2 days after hCG treatment and remained elevated for the rest of the study. Small antral follicles (< 0.5 cm) were initially observed bilaterally in both dolphins on day 4. In both animals on day 9, there were > 12 follicles/ovary, ranging from 0.5 to 1.5 cm. By day 22, the multiple follicles ranged from 0.5 to 4.5 cm in diameter. No ultrasonographic evidence of luteal formation was observed. The results indicate that 1) transabdominal ultrasonography can be used to detect and follow follicle growth in bottlenose dolphins; 2) bottlenose dolphins are sensitive to exogenous gonadotropins (multiple follicular recruitment of follicles occurred); and 3) until further ultrasonographic studies can be conducted to evaluate the effects of titrated doses of exogenous gonadotropins, these protocols should be considered unsuitable for ovulation induction.

Biology of Reproduction, May 1, 2004

Research was conducted to develop an effective method for cryopreserving bottlenose dolphin (Turs... more Research was conducted to develop an effective method for cryopreserving bottlenose dolphin (Tursiops truncatus) semen processed immediately after collection or after 24-h liquid storage. In each of two experiments, four ejaculates were collected from three males. In experiment 1, three cryopreservation methods (CM1, CM2, and CM3), two straw sizes (0.25 and 0.5 ml), and three thawing rates (slow, medium, and fast) were evaluated. Evaluations were conducted at collection, prefreeze, and 0-, 3-, and 6-h postthaw. A sperm motility index (SMI; total motility [TM] ؋ % progressive motility [PPM] ؋ kinetic rating [KR, scale of 0-5]) was calculated and expressed as a percentage MI of the initial ejaculate. For all ejaculates, initial TM and PPM were greater than 85%, and KR was five. At 0-h postthaw, differences in SMI among cryopreservation methods and thaw rates were observed (P Ͻ 0.05), but no effect of straw size was observed. In experiment 2, ejaculates were divided into four aliquots for dilution (1:1) and storage at 4؇C with a skim milkglucose or a N-tris(hydroxymethyl)methyl-2-aminoethane sulfonic acid (TES)-TRIS egg yolk solution and at 21؇C with a Hepes-Tyrode balanced salt solution (containing bovine albumin and HEPES) (TALP) medium or no dilution. After 24 h, samples were frozen and thawed (CM3, 0.5-ml straws, fast thawing rate) at 20 ؋ 10 6 spermatozoa ml ؊1 (low concentration) or at 100 ؋ 10 6 spermatozoa ml ؊1 (standard concentration). The SMI at 0-h postthaw was higher for samples stored at 4؇C than for samples stored at 21؇C (P Ͻ 0.001), and at 6-h postthaw, the SMI was higher for samples frozen at the standard concentration than for samples frozen at the low concentration (P Ͻ 0.05). For both experiments, acrosome integrity was similar across treatments. In summary, a semen cryopreservation protocol applied to fresh or liquid-stored semen maintained high levels of initial ejaculate sperm characteristics.

Theriogenology wild, 2023

Frontiers in Marine Science, Nov 22, 2021

The few hormone studies on bottlenose dolphin (Tursiops truncatus) pregnancy with different repro... more The few hormone studies on bottlenose dolphin (Tursiops truncatus) pregnancy with different reproductive outcomes, e.g., normal birth, stillbirth and abortion, have mostly focused on progestagens or relaxin. However, recent analysis of androgens, glucocorticoids and estrogens has shown they are also biomarkers of cetacean pregnancy. Therefore, our objective was to examine circulating concentrations of androgens, glucocorticoids and estrogens during bottlenose dolphin pregnancies with different reproductive outcomes, including normal pregnancy (NORM, n = 27), failure to thrive (FTT, n = 17), perinatal loss (PNL, n = 20), early loss (EL, n = 12) and false pregnancy (FP, n = 16), to determine if they could be potential indicators of reproductive or fetal health. We analyzed longitudinal serum samples (n = 654) from 57 bottlenose dolphins and 92 reproductive events for testosterone, androstenedione, cortisol, estradiol and estrone conjugates. Testosterone concentrations were higher during EL compared to NORM and lower during FP at MID (day 121-240 post ovulation/conception) and LATE (day 241-end of FP) stages (months post conception/ovulation [MPC, MPO] seven through ten, P < 0.05). During FTT, androstenedione concentrations were increased compared to NORM pregnancies in the EARLY and LATE stages (P ≤ 0.05), and concentrations were reduced during FP (P < 0.05). For cortisol, FTT pregnancies had higher concentrations compared to NORM during all stages (P < 0.05), while PNL had higher cortisol during EARLY and LATE stages (P < 0.05). Estradiol concentrations were lower for EL and FP compared to NORM (P < 0.05), while estrone conjugates were only reduced during FP (P < 0.05). Based on our results only cortisol may be a useful predictor of PNL, while both cortisol and androstenedione were useful for distinguishing FTT pregnancies. Similarly, both testosterone and estradiol during EL and FP were different from NORM. Our data

DNA methylation data have been successfully used to develop highly accurate estimators of age ("e... more DNA methylation data have been successfully used to develop highly accurate estimators of age ("epigenetic clocks") in several mammalian species. With a view of extending epigenetic clocks to primates, we analyzed DNA methylation profiles from five primate species; Papio hamadryas (baboons), Callithrix jacchus (common marmoset), Chlorocebus sabaeus (vervet monkey), Macaca mulatta (rhesus macaque), and Homo sapiens (human). From these we present here, a highly accurate primate epigenetic clock. This clock is based on methylation profiles of CpGs that are highly conserved and are located on a custom methylation array (HorvathMammalMethylChip40). Furthermore, we carried out in-depth analysis of the baboon, as it is evolutionarily the closest primate to humans that can be employed in biomedical research. We present five epigenetic clocks for baboons (Olive-yellow baboon hybrid), one of which, the pan tissue epigenetic clock, was trained on seven tissue types (fetal cerebral cortex, adult cerebral cortex, cerebellum, adipose, heart, liver, and skeletal muscle) with ages ranging from late fetal life to 22.8 years of age. To facilitate translational capability, we constructed two dual-species, human-baboon clocks, whereby one measures ages of both species in units of years, while the other reports ages relative to the maximum lifespan of the species. Although the primate clock applies to all five primate species, the baboon-specific clocks exhibit only moderate age correlations with other primates. We also provide detailed gene and pathway analyses of individual CpGs that relate to age and sex across different primate species. Ten out of 739 sex related CpGs in primate species are located near 9 autosomal genes (including FAM217A, CDYL, POU3F2, and UHRF2). Overall, this study sheds light on epigenetic aging mechanisms in primates, and the potential influence of sex.

Journal of the Acoustical Society of America, Oct 1, 2019

Killer whales (Orcinus orca) are an apex predator, the largest delphinid odontocete, and have the... more Killer whales (Orcinus orca) are an apex predator, the largest delphinid odontocete, and have the widest cosmopolitan distribution of all cetacean species. These long-lived animals can be found in life-long matrilineal groups, where fitness-related activities such as cooperative hunting rely on sophisticated group coordination, often mediated by acoustic communication. The effects of anthropogenic noise on the fitness of killer whales is a growing concern, especially for the endangered population of southern resident killer whales. Although modest progress has been made in determining the killer whales’ behavior in response to noise (e.g., Lombard effect), almost nothing is known about how these animals hear in noisy environments. Here, what is known about killer whale hearing is summarized, including behavioral and electrophysiological audiograms, and resulting auditory weighting functions. In addition, new critical ratio data are presented and compared with other odontocete species. These preliminary data are evaluated in a communication space model to predict negative impacts of anthropogenic noise.