Biomedical subjects

S L Monfort

Publications and source records attributed to S L Monfort.

At least 19 recordsLinked to original sources

PubMed2005

Characterization of male killer whale (Orcinus orca) sexual maturation and reproductive seasonality.

Longitudinal serum testosterone concentrations (n=10 males) and semen production (n=2 males) in killer whales were evaluated to: (1) characterize fluctuations in serum testosterone concentrations with respect to reproductive maturity and season; (2) compare morphologic changes to estimated age of sexual maturity, based on changes in serum testosterone concentrations; and (3) evaluate seasonal changes in sperm production. Classification of reproductive status and age class was based on differences (P < 0.05) in serum testosterone concentrations according to age; juvenile males ranged from 1 to 7 years (mean+/-S.D. testosterone, 0.13+/-0.20 ng/mL), pubertal males from 8 to 12 years (2.88+/-3.20 ng/mL), and sexually mature animals were 13 years and older (5.57+/-2.90 ng/mL). For captive-born males, serum testosterone concentrations, total body length and height to width ratio of the dorsal fin were 0.7+/-0.7 ng/mL, 495.6+/-17.5 cm and 1.14+/-0.13c m, respectively, at puberty; at sexual maturity, these end points were 6.0+/-3.3 ng/mL, 548+/-20 cm and 1.36+/-0.1cm. Serum testosterone concentrations were higher (P<0.05) from March to June than from December to February in pubertal animals (4.2+/-3.4 ng/mL versus 1.4+/-2.6 ng/mL) and than from September to December in sexually mature animals (7.2+/-3.3 ng/mL versus 4.0+/-2.0 ng/mL). Ejaculates (n = 90) collected from two males had similar (P > 0.05) sperm concentrations across all months. These data represent the first comprehensive study on male testosterone concentrations during and after sexual maturation, and on reproductive seasonality in the killer whale.

Aging↗

PubMed2005

Estrous cycle characterisation and artificial insemination using frozen-thawed spermatozoa in the bottlenose dolphin (Tursiops truncatus).

The reproductive endocrinology of the bottlenose dolphin, Tursiops truncatus, was characterized to facilitate the development of artificial insemination using cryopreserved spermatozoa. Specific objectives were: (i) to determine the excretory dynamics of urinary luteinizing hormone (LH) and ovarian steroid metabolites during the estrous cycle; (ii) to evaluate the effect of an exogenously administered synthetic progesterone analog (altrenogest) on reproductive hormone excretion; (iii) to correlate follicular growth and ovulation (as determined by transabdominal ultrasound) to urinary LH and ovarian steroid metabolites; (iv) examine the in vivo fertilisation capacity of cryopreserved semen, and (v) to develop an intrauterine insemination technique. Based on urinary endocrine monitoring of natural estrous cycles (2 consecutive cycles) and nine post altrenogest cycles in ten females, estrous cycles were found to be 36 days long and comprised of an 8 day and 19 day follicular and luteal phase, respectively. Peak estrogen conjugates (EC; 5.4+/-3.8 ng/mg creatinine (Cr)) occurred 8 h prior to the LH surge (70.9+/-115.7 ng/mg Cr). The time of ovulation, as determined by ultrasonography, occurred 32.1+/-8.9 h and 24.3+/-7.0 h after the onset of the LH surge and LH peak, respectively. Mean preovulatory follicular diameter and circumference were 2.1+/-0.5 cm and 6.5+/-1.5 cm, respectively. Of the 27 estrous synchronisation attempts, 13 resulted in an ovulatory cycle, with ovulation occurring 21 days post-altrenogest treatment. Intrauterine (4 of 5) and intracornual (1 of 3) inseminations conducted across eight estrous cycles resulted in five pregnancies (63%), one pregnancy resulted from the use of liquid stored semen, whereas four were achieved using cryopreserved semen. These data provide new information on female bottlenose dolphin reproductive physiology, and demonstrate that the combination of endocrine monitoring and serial ultrasonography contributed to successful AI using liquid-stored and cryopreserved semen.

Animals↗

PubMed2005

Frequent serial fecal corticoid measures from rats reflect circadian and ovarian corticosterone rhythms.

The circadian glucocorticoid rhythm provides important information on the functioning of the hypothalamic-pituitary-adrenal axis in individuals. Frequent repeated blood sampling can limit the kinds of studies conducted on this rhythm, particularly in small laboratory rodents that have limited blood volumes and are easily stressed by handling. We developed an extraction and assay protocol to measure fecal corticosterone metabolites in repeated samples collected from undisturbed male and female adult Sprague-Dawley rats. This fecal measure provides a non-invasive method to assess changes in corticosterone within a single animal over time, with sufficient temporal acuity to quantify several characteristics of the circadian rhythm: e.g. the nadir, acrophase, and asymmetry (saw-tooth) of the rhythm. Males excreted more immunoreactive fecal corticoids than did females. Across the estrous cycle, females produced more fecal corticoids on proestrus (the day of the preovulatory luteinizing hormone surge) than during estrus or metestrus. These results establish a baseline from which to study environmental, psychological, and physiological disturbances of the circadian corticosterone rhythm within individual rats.

Adrenal Cortex Hormones↗

PubMed2004

Reproductive physiology and development of artificial insemination technology in killer whales (Orcinus orca).

Research was conducted to define the basic reproductive physiology of killer whales (Orcinus orca) and to use this knowledge to facilitate the development of artificial insemination procedures. The specific objectives were 1) to determine the excretory dynamics of urinary LH and ovarian steroid metabolites during the estrous cycle; 2) to evaluate the effect of an exogenously administered, synthetic progesterone analog on reproductive hormone excretion; 3) to validate the use of transabdominal ultrasound for ovarian evaluation and timing of ovulation; 4) to examine the quality of semen after liquid storage and cryopreservation; and 5) to develop an intrauterine insemination technique. Based on urinary endocrine monitoring of 41 follicular phases and 26 complete cycles from five females, estrous cycles were 41 days long and comprised a 17-day follicular phase and a 21-day luteal phase. A consistent temporal relationship was observed between peak estrogen conjugates and the LH surge, the latter of which occurred approximately 0.5 days later. Two animals placed on oral altrenogest (three separate occasions for 30, 17, and 31 days, respectively) excreted peak urinary estrogen concentrations 25 days after withdrawal that were followed by sustained elevations in urinary pregnanediol-3alpha-glucuronide excretion. Mean preovulatory follicle diameter was 3.9 cm (n = 6), and ovulation occurred 38 h (n = 5) after the peak of the LH surge. Based on visual estimates of motility, liquid-stored semen maintained 92% of its raw ejaculate sperm motility index (total progressive motility x kinetic rating [0-5 scale, where 0 = no movement and 5 = rapid progressive movement]) when held at 4 degrees C for 3 days postcollection. Semen cryopreserved using a medium freezing rate demonstrated good postthaw total motility (50%), progressive motility (94%), and kinetic rating (3.5). Insemination during eight estrous cycles resulted in three pregnancies (38%), two from liquid-stored and one from cryopreserved semen. Two calves were delivered after gestation lengths of 552 and 554 days, respectively. These data demonstrate the potential of noninvasive endocrine monitoring combined with serial ultrasonography to improve our understanding of the reproductive biology of cetaceans. This fundamental knowledge was essential for ensuring the first successful conceptions, resulting in live offspring, using artificial insemination in any cetacean species.

Acrosome↗

PubMed2004

Noninvasive monitoring of adrenocortical activity in carnivores by fecal glucocorticoid analyses.

Measurement of glucocorticoid metabolites in feces has become an accepted method for the noninvasive evaluation of adrenocortical activity. The objective of this study was to determine if a simple cortisol enzyme immunoassay (EIA) was suitable for monitoring adrenocortical activity in a variety of carnivore species. Performance of the cortisol EIA was gauged by comparison to a corticosterone radioimmunoassay (RIA) that has been used for measuring glucocorticoid metabolites in feces of numerous species. Tests for parallelism and extraction efficiency were used to compare the cortisol EIA and corticosterone RIA across eight species of carnivores (Himalayan black bear, sloth bear, domestic cat, cheetah, clouded leopard, black-footed ferret, slender-tailed meerkat, and red wolf). The biological relevance of immunoreactive glucocorticoid metabolites in feces was established for at least one species of each Carnivora family studied with an adrenocorticotropic hormone (ACTH) challenge. High performance liquid chromatography (HPLC) analysis of fecal extracts for each species revealed (1) the presence of multiple immunoreactive glucocorticoid metabolites in feces, but (2) the two immunoassays measured different metabolites, and (3) there were differences across species in the number and polarities of metabolites identified between assay systems. ACTH challenge studies revealed increases in fecal metabolite concentrations measured by the cortisol EIA and corticosterone RIA of approximately 228-1145% and approximately 231-4150% above pre-treatment baseline, respectively, within 1-2 days of injection. Concentrations of fecal glucocorticoid metabolites measured by the cortisol EIA and corticosterone RIA during longitudinal evaluation (i.e., >50 days) of several species were significantly correlated (P<0.0025, correlation coefficient range 0.383-0.975). Adrenocortical responses to physical and psychological stressors during longitudinal evaluations varied with the type of stimulus, between episodes of the same stimulus, and among species. Significant elevations of glucocorticoid metabolites were observed following some potentially stressful situations [anesthesia (2 of 3 subjects), restraint and saline injection (2 of 2 subjects), restraint and blood sampling (2 of 6 episodes), medical treatment (1 of 1 subject)], but not in all cases [e.g., gonadotropin injection (n=4), physical restraint only (n=1), mate introduction/breeding (n=1), social tension (n=1), construction (n=2) or relocation (n=1)]. Results reinforced the importance of an adequate baseline period of fecal sampling and frequent collections to assess adrenocortical status. The corticosterone RIA detected greater adrenocortical responses to exogenous ACTH and stressful exogenous stimuli in the Himalayan black bear, domestic cat (female), cheetah, clouded leopard, slender-tailed meerkat, and red wolf, whereas the cortisol EIA proved superior to resolving adrenocortical responses in the black-footed ferret and domestic cat (male). Overall results suggest the cortisol EIA tested in this study offers a practical method for laboratories restricted in the usage of radioisotopes (e.g., zoological institutions and field facilities) to integrate noninvasive monitoring of adrenocortical activity into studies of carnivore behavior and physiology.

Acinonyx↗

PubMed2002

Computer simulations to determine the efficacy of different genome resource banking strategies for maintaining genetic diversity.

Genome resource banks (GRBs) and assisted reproductive techniques are increasingly recognized as useful tools for the management and conservation of biodiversity, including endangered species. Cryotechnology permits long-term storage of valuable genetic material. Although, the actual application to endangered species management requires technical knowledge about sperm freezing and thawing, a systematic understanding of the quantitative impacts of various germ plasm storage and use scenarios is also mandatory. In this study, various GRB strategies were analyzed using the historical data from three managed populations of endangered species with varied pedigrees (Eld's deer, Przewalski's horse, and Sumatran tiger). The following types of sperm banks were assessed: (1) a "Wild Bank" consisting of sperm (i.e., genes) from 5 to 10 males unrelated to the managed population and to each other; and (2) a "Best Male" bank containing sperm from only the most genetically valuable males alive in the ex situ population at the time the bank was established. These different bank types were then used to evaluate the effectiveness of different bank usage frequencies. The efficiency of each scenario was assessed by examining the level of inbreeding and gene diversity in the population. Overall, a sperm usage frequency of five times per year was determined to be the most efficient and "wild banks" were highly successful at enhancing genetic diversity. The value of a GRB established from the ex situ population depends on how closely related the banked males are to future generations. A GRB will have significantly less benefit when banked males also produce many successful offspring, or when donors are already genetically over-represented in the population at the time of establishing the GRB.

Animals↗

PubMed2001

Sperm capacitation in vitro in the eld's deer.

Sperm capacitation was examined in the endangered Eld's deer (Cervus eldi thamin). Sperm motility and viability (percentage of sperm cells with intact membranes) were assessed in vitro over time after attempting to induce capacitation in TALP alone and TALP supplemented with calcium (10 mM CaCl2), dibutyryl cAMP (1 mM dbcAMP), or fetal calf serum (20% FCS). Sperm aliquots were evaluated at 0, 3, 6, 9, and 12 h for motility, viability, and ability to acrosome react after exposure to calcium ionophore (A23187, CI; 10 microM) or lysophosphatidylcholine (LC; 100 microg/mL). Fresh sperm aliquots in TALP + 10 mM CaCl2 exposed to CI had fewer (P < 0.05) intact acrosomes than the TALP control (TALP alone) or dbcAMP and FCS treatments after 9 h. Mean (+/- SEM) percentage of intact acrosomes of spermatozoa incubated in medium with increased CaCl2 declined (P < 0.05) from 80.2 +/- 2.6% (0 h) to 49.7 +/- 7.3% after prolonged incubation (9 h). The proportion of capacitated fresh spermatozoa was not influenced by LC treatment. Capacitation was not induced (P > 0.05) by any of the presumptive sperm capacitators after freeze-thawing. Likewise, neither CI nor LC induced the acrosome reaction (AR) in these spermatozoa, suggesting that the freeze-thawing process may have caused membrane damage. Results revealed that the supplementation of medium with CaCl2 evokes capacitation in some spermatozoa. However, Eld's deer spermatozoa appear remarkably resistant to conventional stimulators of capacitation and the AR.

Acrosome Reaction↗

PubMed2001

Longitudinal gonadal steroid excretion in free-living male and female meerkats (Suricata suricatta).

Slender-tailed meerkats (Suricata suricatta) are small, diurnal, cooperatively breeding mongooses of the family Herpestidae. A prerequisite to fully understanding the mating system of meerkats is the development of a normative reproductive-endocrine database. This study examined longitudinal gonadal steroid excretion in all adult and juvenile individuals of both sexes within a social group of free-living meerkats sampled across an entire breeding season. The specific objectives of this study were to (1) validate noninvasive (fecal and urinary) gonadal steroid hormone monitoring techniques in male (testosterone) and female (estrogens, progestagens) meerkats; (2) test the feasibility of using these noninvasive methods under field conditions; (3) characterize the endocrine correlates associated with the female reproductive cycle, including estrus, gestation, and postpartum estrus; (4) examine longitudinal androgen excretion in males; and (5) determine whether social status (i.e., dominant versus subordinate) affected gonadal steroid excretion. In females, the results demonstrated the physiological validity of noninvasive monitoring in meerkats by corresponding excretory hormone concentrations to major reproductive events (i.e., estrous, pregnancy, parturition). Hormone excretory patterns during estrous intervals suggested possible mechanisms whereby reproductive suppression may operate in female meerkats. In males, androgen excretion did not correspond to changes in reproductive and aggressive behaviors, suggesting that dominance, and hence breeding access to females, was not regulated strictly by gonadal steroid production. The consistency in androgen excretion among male meerkats indicated that reproductive suppression may be mediated by behavioral (i.e., intermale aggression) rather than physiological (i.e., depressed spermatogenesis) mechanisms.

Animals↗

PubMed2000

Comparing ovulation synchronization protocols for artificial insemination in the scimitar-horned oryx (Oryx dammah).

Ovarian response and pregnancy success in scimitar-horned oryx (n=28) were compared, following treatment with two synchronization protocols and fixed-time artificial insemination (AI) with frozen-thawed semen. Each oryx received two injections of 500 microg of prostaglandin-F(2alpha) analogue (PGF(2alpha)-only) 11 days apart, and half received PGF(2alpha) in combination with an intravaginal progesterone-releasing device (CIDR11+PGF(2alpha)). Semen was collected by electroejaculation from anaesthetised adult oryx and cryopreserved. Anaesthetised females were transcervically inseminated 56.0+/-1.1 h (+/-S.E.M.) after PGF(2alpha) injection and/or device withdrawal using 28.0+/-1.5x10(6) motile thawed sperm. Ovarian endocrine response was monitored in 20 females by analysing faecal oestrogen and progesterone metabolites. Periovulatory oestrogen peaks were detected in 19/20 (95%) females after synchronization. There were no between-treatment differences in oestrogen concentrations or peak characteristics (P0.05). Luteal development after synchronization was delayed in half the progesterone treated (CIDR11+PGF(2alpha)) females, and faecal progestin excretion profiles indicated that the ovulatory follicle associated with synchronization either failed to ovulate or to fully lutenise. Pregnancy was diagnosed by ultrasonography and/or rectal palpation and was monitored by faecal progestin excretion. More (P=0. 013) pregnancies resulted from the PGF(2alpha)-only treatment (37.5%, 5/14) than from the CIDR11+PGF(2alpha) treatment (0/14), and four healthy scimitar-horned oryx calves were born, three after gestation intervals of 247 days and one after 249 days.

Administration, Intravaginal↗

PubMed2000

A generalized fecal glucocorticoid assay for use in a diverse array of nondomestic mammalian and avian species.

Noninvasive fecal glucocorticoid analysis has tremendous potential as a means of assessing stress associated with environmental disturbance in wildlife. However, interspecific variation in excreted glucocorticoid metabolites requires careful selection of the antibody used in their quantification. We compared four antibodies for detecting the major fecal cortisol metabolites in yellow baboons following (3)H cortisol administration, ACTH challenge, and HPLC separation of fecal glucocorticoid metabolites. The most effective antibody (ICN corticosterone RIA; Cat. No. 07-120102) demonstrated relatively high cross-reactivities to the major cortisol metabolites present in feces during peak excretion, following both radiolabel infusion and ACTH challenge. This same antibody also detected increased fecal glucocorticoid metabolites after ACTH administration in the African elephant, black rhinoceros, Roosevelt elk, gerenuk, scimitar-horned oryx, Alaskan sea otter, Malayan sun bear, cheetah, clouded leopard, longtailed macaque, and northern spotted owl. Results suggest that (1) fecal glucocorticoid assays reliably detect endogenous changes in adrenal activity of a diverse array of species and (2) where comparisons were made, the ICN corticosterone antibody generally was superior to other antibodies for measuring glucocorticoid metabolites in feces.

Adrenocorticotropic Hormone↗

PubMed2000

Seasonal patterns of LH, testosterone and semen quality in the Northern pintail duck (Anas acuta).

This study characterized seasonal changes in circulating LH and testosterone and in semen production and quality in the Northern pintail duck. Plasma LH and testosterone were measured in blood samples collected weekly throughout the year from eight males exposed to natural fluctuations in day length and temperature. Semen quality was evaluated weekly in these same males from April-June, the months when spermatozoa were produced. Semen quality (based on sperm concentration and normal morphology) peaked 0-2 weeks after sperm production onset and decreased sharply before sperm production cessation in late June. Nadir LH concentrations were measured in July and August with peak LH observed in May and November. There were clear seasonal patterns in circulating testosterone with July-September values being less (P<0.05) than October-December which, in turn, were less (P<0.05) than January-March. Maximal circulating testosterone (P<0.05) occurred during April-June, coincident with semen production. Weekly circulating LH during the breeding season was directly related to testosterone concentrations (P<0.01), but was not correlated to any specific semen or sperm trait (P>0.05). Testosterone concentrations throughout the breeding season were correlated (P<0.05) to total numbers of spermatozoa produced (volume x cell concentration) and percent normal sperm morphology. In summary, the Northern pintail experiences seasonal hormone fluctuations, with maximum circulating testosterone coinciding with peak ejaculate quality reflected by the production of high numbers of morphologically normal spermatozoa.

Animals↗

PubMed2000

Anesthesia in female white-tailed deer using Telazol and xylazine.

Thirty two free-ranging female white-tailed deer (Odocoileus virginianus) were anesthesized with varying Telazol and xylazine HCl combinations in Front Royal (Virginia, USA) between August 1992 and September 1992. All animals were caught in baited box traps, manually restrained, and hand injected with a combination of Telazol and xylazine administered intramuscularly. Deer received mean +/- SE dosages of 2.53+/-0.16 mg/kg Telazol and 0.69+/-0.05 mg/kg of xylazine. These dosages achieved a rapid and effective anesthetic plane for short-term procedures such as weighing, blood collection, and translocation. Eight of 32 deer (25%) required an intravenous (i.v.) supplement of ketamine HCl (100 mg) to maintain a safe plane of anesthesia. Ketamine supplementation provided an average of 11.8+/-2.0 min additional safe handling. Satisfactory reversals were achieved in all deer by administering yohimbine HCl 16 mg i.v. (dose range, 0.22 to 0.48 mg/kg) to all animals.

Adrenergic alpha-Agonists↗

PubMed1999

Synchronization of oestrous cycles in sable antelope.

Techniques for manipulating the oestrous cycle of sable antelope, Hippotragus niger, were evaluated in a captive population of 24 females maintained at the Smithsonian Institution's Conservation and Research Center in Front Royal, VA, USA. A secondary objective was to demonstrate the effectiveness of fecal steroid monitoring techniques as a non-invasive method of tracking experimental manipulations. Controlled Internal Drug Releasing (CIDR) devices designed for cattle (type B, reduced in length by 5 cm to fit the sable antelope's smaller reproductive tract) were more effective than CIDR devices designed for goats (type G) at delivering progesterone into circulation, and maintained serum progesterone at levels up to 86.1+/-7.8% of normal luteal concentrations in females whose spontaneous ovarian activity had been inhibited with melengestrol acetate. Serum progesterone and fecal progestagen measurements were highly correlated (P<0.05). Synchronization treatments of prostaglandin (PG) F2alpha alone and in combination with modified CIDR-B devices (12-day insertion interval) were both effective in inducing synchronized ovulation, however the PGF2alpha/modified CIDR-B treatment resulted in more precise synchrony and a shorter latency to ovulation than did PGF2alpha alone. In a separate experiment to characterize the temporal relationship between synchronization treatment, behavioral oestrus and ovulation, onset of behavioral oestrus occurred 34.1+/-5.7 h following PGF2alpha/modified CIDR-B treatment. Mean duration of the induced oestrus was 24.9+/-4.3 h. The first detectable rise in fecal progestagens occurred 5.1+/-1.0 and 4.1+/-1.0 days following PGF2alpha/modified CIDR-B treatment in groups of females housed with and without an adult male, respectively, indicating that the presence of a male did not accelerate the onset of the induced cycle.

Administration, Intravaginal↗

PubMed1999

Stag exposure advances the LH surge and behavioral estrus in Eld's deer hinds after CIDR device synchronization of estrus.

The impact of male presence or absence on the timing of the preovulatory LH surge and estrus was studied in 3 experimental groups (n = 6/group) of Eld's deer hinds pretreated with intravaginal progesterone-releasing devices (CIDR-type G) as follows: Group 1 = indirect male contact barn; Group 2 = direct male contact barn; and Group 3 = male isolation barn. For all hinds, the duration of the preovulatory LH surge averaged 2.5+/-0.5 h, whereas mean peak preovulatory and basal LH concentrations were 2.9+/-0.2 ng mL(-1) and 0.27+/-0.03 ng mL(-1), respectively. Nine of 12 male-exposed hinds exhibited a preovulatory LH surge within 24 to 32 h postCIDR device withdrawal, whereas 0 of 6 male-isolated hinds exhibited a preovulatory LH surge during the same time period. Onset of behavioral estrus (45.2+/-2.3, 52.7+/-5.7 and 66.3+/-1.8 h, respectively) was significantly advanced (P<0.05) after CIDR device withdrawal in male exposed hinds (Groups 1 and 2) compared with male isolated hinds (Group 3). These data suggest that stag exposure is important for modulating the timing of the preovulatory LH surge and behavioral estrus after synchronization of estrus with exogenous progestagens.

Administration, Intravaginal↗

PubMed1999

Comparative reproductive function in cervids: implications for management of farm and zoo populations.

The cervids represent a complex assemblage of taxa characterized by extreme diversity in morphology, physiology, ecology and geographical distribution. Farmed species (for example red deer and fallow deer) are usually the common larger-bodied, gregarious and monotocous species that express marked reproductive seasonality in their temperate environment. Their commercial importance has facilitated considerable research into reproductive physiology and the development of assisted reproductive technologies (ART). In contrast, the remaining species, including many of tropical origin, show wide diversity in reproductive patterns, have generally received little scientific scrutiny, and include a number of endangered taxa that are reliant on ex situ conservation efforts (such as captive breeding) to ensure their survival. Domestication and ex situ management programmes have been associated with widespread translocation of various cervid species around the world, often placing the animals in environments that are not compatible with their evolved reproductive patterns. For example, the summer calving/lactation pattern of red deer, attuned to northern continental climatic patterns, is frequently misaligned with seasonal changes in feed availability in the Australasian pastoral environment. Similarly, seasonal or aseasonal calving patterns of tropical species translocated to temperate regions are usually associated with increased perinatal mortality of calves born in cool seasons. Conversely, temperate species in tropical zones may exhibit aberrant reproductive patterns in the absence of biologically significant photoperiod fluctuations. ARTs, which presently include artificial insemination, embryo transfer and in vitro embryo production, have potential application to the genetic management and population growth of various cervid species. Although application to some farmed cervid species is widespread, these technologies are rarely directly transferable from farmed to endangered species. Even within species, ART protocols developed successfully for one genotype (i.e. subspecies) may be ineffective in another (for example superovulation of red deer and wapiti). Therefore, application to genetic management of endangered species necessitates prior research into their reproductive patterns. This is often difficult because of the rarity of the animals, a lack of suitable handling facilities for the particular species, and the timid nature of the deer. More recently, however, non-invasive reproductive profiling, based on remote collection and monitoring of excreted steroid metabolites, has facilitated such research.

Animals↗

PubMed1998

Abdominal lipomatosis attributed to tall fescue toxicosis in deer.

Five adult female Eld's deer died acutely or were euthanatized because of clinical signs including anorexia, signs of depression, and uremia. On necropsy, these deer had large masses of necrotic abdominal fat constricting the ureters, causing hydroureter and hydronephrosis. The herd from which these deer originated was maintained on pastures consisting primarily of tall fescue, samples from which were subsequently confirmed to be infected with an endophytic fungus that is known to cause similar lesions in cattle. A retrospective study of deaths in this herd revealed a sharp increase in incidence of abdominal lipomatosis since 1994. Physical examinations on the herd revealed > 90% of females to be affected. Endophyte-infected tall fescue forage was concluded to be a major factor in the development of lipomatosis in these deer. Other contributing factors were considered. Lesions caused by endophyte-infected fescue can be severe, and this disease can develop in nondomestic species.

Acremonium↗

PubMed1998

Longitudinal fecal steroid excretion in maned wolves (Chrysocyon brachyurus).

This study used a fecal steroid monitoring technique to evaluate reproductive cycles in male (4) and female (15) maned wolves, endangered South American canids. A radiolabeled testosterone infusion on a male revealed a fast and predominantly fecal route of excretion for this steroid. Testosterone was also excreted as eight unidentified metabolites, which was not the primary form of this steroid quantified in our assays. Fecal steroid concentrations (estradiol, E2; progestins, P; testosterone, T) in males and acyclic, nonpregnant (pseudo-pregnant), and pregnant females were monitored over four breeding seasons (October-January). Significant differences were detected between longitudinal P profiles of cyclic and acyclic females during estrus, luteal phase, and after birth/end of pseudo-pregnancy. Concentrations of P were also significantly higher in pregnant, compared to nonpregnant females, from proestrus to the end of the pregnant luteal phase. Although levels of T were higher in males than in females throughout the breeding season, no cyclicity in male fecal T concentrations was detected. Values of fecal P, T, and the ratio P/T were useful for differentiating gender and detecting pregnancy in females. Similarities to available data on other canids and the management and conservation implications of these findings were discussed.

Animals↗

PubMed1998

Characterization of estrous cyclicity in the sable antelope (Hippotragus niger) through fecal progestagen monitoring.

Fecal progesterone metabolite monitoring techniques were validated for the sable antelope and used to characterize ovarian cycle dynamics and reproductive seasonality in a captive population at the National Zoological Park's Conservation and Research Center. Hormone was homogeneously distributed within fecal samples. Longitudinal fluctuations in fecal progesterone metabolites were consistent with typical luteal phase patterns and corresponded closely with changes in serum progesterone. The lag time from an im injection of progesterone to peak excretion in feces was 16 h. The pattern of births showed a slight peak in the summer (May-July), but year-round endocrine monitoring of six nonpregnant females showed no evidence of seasonality in ovarian activity. Females exhibited 11-14 estrous cycles per year, averaging 24.2 +/- 0.9 days in length. Luteal and interluteal phases were 18.4 +/- 0.9 and 5.8 +/- 0.4 days in length, respectively. Although only a small number of hippotragine antelope species have been studied, data indicate that they exhibit considerable interspecific variability in estrous cycle length and reproductive seasonality and thus may be a useful group for further investigation of factors regulating fertility.

Animals↗