Fecal Steroid Metabolites Research Articles

Non-invasive assessment of fecal glucocorticoid, progesterone, and androgen metabolites and microbiome in free-ranging southern white rhinoceros (Ceratotherium simum simum) in South Africa

Increased poaching in northern South Africa has necessitated relocation of large numbers of southern white rhinoceros (Ceratotherium simum simum) to the Eastern Cape Province. The climate and grassland ecology of this province differ from that of northern South Africa which may impact the health of this species. This assessment of fecal steroid levels and microbiome in 10 free-ranging southern white rhinoceros in the Eastern Cape will provide insights into white rhinoceros physiology in this biome. Fecal steroid metabolites were analyzed using enzyme immunoassay (EIA) and ultra-performance convergence chromatography tandem mass spectrometry (UPC2-MS/MS). Fecal microbial composition was assessed via next generation sequencing. EIAs with antibodies raised against progesterone (P4; mouse monoclonal – CL425 clone), testosterone (T; rabbit polyclonal), corticosterone (B; sheep polyclonal) were utilized. Pregnant females had large quantities of fecal progesterone metabolites (FPMs) detected by CL425 EIA. Pregnant females also had native P4 and 11α-hydroxydihydroprogesterone (11αOHDHP4; 4-pregnen-11α-ol-3,20-dione) detected by UPC2-MS/MS but these concentrations were 1000-fold less than the concentrations of FPMs detected by the CL425 EIA. By contrast, non-pregnant females had FPM concentrations detected by CL425 EIA which were similar to native P4 and 11αOHDHP4 concentrations detected by UPC2-MS/MS. Mean fecal androgen metabolite (FAM) concentrations detected by the T EIA were similar between males and females. 11-ketoandrostenedione (11KA4) detected by UPC2-MS/MS was higher in females than males. However, there was no difference between males and females in the concentration of fecal glucocorticoid metabolites (FGMs) detected by the B EIA. Bacteroidia, followed by Clostridia, was the most abundant classes of fecal microbes. The unfiltered microbiome of females was more diverse than that of males. The core fecal microbiome of young rhinoceros had a higher observed species richness (Shannon diversity index, and Simpson diversity index) than that of old rhinoceros. In the alpha male, immobilization was associated with an increase in FGMs detected by 11-deoxycortisol (S) detected by UPC2-MS/MS coupled with decreased abundance of Spirochaetia. We detected substantially different FAM and FPM concentrations from those previously reported for both captive and wild white rhinoceros. Comparison of our UPC2-MS/MS and EIA results underscores the fact that most EIAs are highly cross reactive for many steroid metabolites. Our data also demonstrates a distinct effect of stress not only on FGMs but also on the fecal microbiome. This is the first non-invasive assessment of fecal steroid metabolites by UPC2-MS/MS and the fecal microbiome in wild white rhinoceros.

Chemical contraceptive impacts on cyclic progesterone and sexual behavior in zoo-housed Western lowland gorillas.

For regularly cycling primates in captivity, chemical contraceptives can be used to reduce the likelihood of unintentional offspring, but the effects on cyclic progesterone and sexual behavior have not been well studied in gorillas (Gorilla gorilla gorilla). As zoos are invested in maintaining naturalistic behaviors and physiology, this is an important aspect of gorilla physical and mental health. We examined how exposure to combination and progestin-only oral birth control pills altered cyclic progesterone and timing of sexual behaviors in four female gorillas at four institutions compared to cycling controls. Hormonal data were collected using fecal steroid metabolites as detected by enzyme immunoassay. Behavioral data were collected via one-zero sampling done by keeper staff. All methods of oral contraceptive eliminated the ovarian cycle, with fecal progestogens being maintained below baselines in cycling control individuals. There was also no evidence of any cyclic patterning in endogenous progesterone, suggesting that the methods tested do not allow for detection of a recovery of endogenous progesterone during a short no-pill period. We also found that the oral contraceptives altered the timing of behavioral displays when compared to cycling control individuals but was not directly related to any fluctuations in endogenous progesterone. This study reveals a need for additional research on contraceptive use in gorillas and reinforces that sexual behavior in gorillas is both hormonally and socially mediated.

Comparative fecal steroid profile during pregnancy, parturition, and lactation between natural fertilization and embryo transfer in ocelots (Leopardus pardalis)

Despite the invaluable role that assisted reproduction technologies (ARTs) play in conservation, pregnancy and parturition rates by embryo transfer (ET) are low for most endangered felids. Thus, efforts to expand the knowledge on pregnancy biology and ET are still required. In this context, we examined fecal sex steroid metabolites (i.e., estrogens, glucocorticoids, and progestogens) of eight ocelots submitted to natural fertilization (NF) and ET in 22 pregnancies (19 NF and 3 ET). Fecal samples were collected and assessed for each pregnancy from estrous cycle, pregnancy, and lactation, totaling 155 days. In short, progestogen levels remained high and unchanged (P < 0.05) from conception until parturition for females maintained under NF. On the other hand, females submitted to ET exhibited changes (P > 0.05) in progestogen levels from conception until parturition, with a significant decrease during pregnancy (480.72 ng/day; r2 = 0.81; P < 0.0001). Significant changes between NF and ET also were noted in estrogen levels between the first and last thirds of pregnancy (P < 0.05), in which estrogen levels exhibited a negative correlation (P < 0.01) between themselves. Regarding glucocorticoids, significant changes (P < 0.01) were observed only in the first third of pregnancy between NF and ET, which we believe may be related to the handling for ovarian synchronization and ET. Besides hormonal changes, the pregnancy was more prolonged (2.5 days) and more prone to dystocia in ET than NF. Overall, 24 embryos were transferred into eight females (3/1), with three kittens being born from three distinct deliveries (i.e., 12.5% of embryos and 37.5% of females). Our findings have supported the great potential of production and transfer of long-term frozen embryos in ocelot conservation. However, they reveal possible effects of these biotechnologies on hormonal levels during pregnancy linked with low conception and parturition rates and dystocic cases in felids.

Immunocontraception of male and female giraffes using the GnRH vaccine Improvac®.

The aim of this study was to develop protocols for contraception in both sexes of giraffes (Giraffa camelopardalis) by using the GnRH vaccine Improvac®. We evaluated the success of immunization by analyzing fecal reproductive hormone metabolites in female (n = 20) and male (n = 9) giraffes. Endocrine analysis provided the basis for the successful immunization protocol, as well as for assessing long‐term effects. Reliable reduction of fecal steroid metabolites to baseline levels in female giraffes was achieved with three, and in males with four or five injections at 4‐week intervals. Effective booster injections were administered at 2‐month intervals in the first year of treatment and at three to 4‐month intervals in the following years. In addition to endocrine analysis, we determined vaccination efficacy in bulls by assessing testicular atrophy. Long‐term (>2 years) use in females was often accompanied by prolonged periods of persistent corpus luteum activity, although normal cycles were not observed. Problems might occur with reversibility, because in a few males and females, even after more than 2 years since treatment had been stopped, fecal hormone metabolites have not returned to pretreatment levels. The results are somewhat ambiguous, as reproduction can be suppressed by use of Improvac®, but the question of reversibility remains unsolved.

Variations, validations, degradations, and noninvasive determination of pregnancy using fecal steroid metabolites in free-ranging pronghorn

Pregnancy status is a key parameter used to assess reproductive performance of a species as it represents a starting point for measuring vital rates. Vital rates allow managers to determine trends in populations such as neonate survival and recruitment; two important factors in ungulate population growth rates. Techniques to determine pregnancy have generally involved capture and restraint of the animal to obtain blood samples for determining serum hormone levels. Non-invasive pregnancy assessment, via feces, eliminates any hazards between handler and animal, as well as removes handling-induced physiological biases. Using noninvasive fecal sampling, we conducted hormone validations, investigated pregnancy rates, and determined hormone degradation rates across five subpopulations of pronghorn (Antilocapra americana) in Idaho. Samples were collected during April-May of 2018 and 2019 from adult pronghorn of known sex and age class. Metabolites of testosterone, cortisol, 17β-estradiol, and progesterone were measured in fecal samples, and concentrations of estradiol and progesterone were examined for pregnancy determination. Average fecal progesterone metabolite (FPM) levels of pregnant females were more than double compared to levels of nonpregnant females. Fecal estrogen metabolite (FEM) levels did not differ during concurrent sampling. The largest difference in FPM levels between pregnant and nonpregnant females began on 28 April. Pregnancy determination sampling showed average FPM levels for all five subpopulations were significantly different than the nonpregnant female validation group. Nonetheless, pregnancy rates for some subpopulations lacked conclusive estimates due to early fecal sampling. Fecal glucocorticoid metabolites (FGM) levels significantly differed between pregnant females and male pronghorn, but did not differ from nonpregnant females. Degradation rates of FPM and FGM differed across days, with values for FPM from Day 1 being significantly different from all subsequent days, and after Day 9 for FGM, demonstrating the requirement of fresh samples to accurately measure hormone concentrations. We concluded that a noninvasive method to diagnosis pregnancy is possible in pronghorn via progesterone metabolites if fresh samples are collected during late gestation.

Assessment of fecal steroid and thyroid hormone metabolites in eastern North Pacific gray whales.

Baleen whale fecal samples have high potential for endocrine monitoring, which can be used as a non-invasive tool to identify the physiological response to disturbance events and describe population health and vital rates. In this study, we used commercial enzyme-linked immunosorbent assays to validate and quantify fecal steroid (progestins, androgens and glucocorticoids) and thyroid hormone metabolite concentrations in eastern North Pacific gray whales (Eschrichtius robustus) along the Oregon coast, USA, from May to October of 2016-2018. Higher mean progestin metabolite concentrations were observed in postweaning females, followed by pregnant females. Mean androgen, glucocorticoid and thyroid metabolites were higher in mature males. Progestin, glucocorticoids and thyroid fecal metabolites varied significantly by year, with positive correlations between progestin and androgen, and between glucocorticoid and thyroid metabolites. We also present two case studies of a documented injured whale and a mature male displaying reproductive competitive behavior, which provide reference points for physiologically stressed individuals and adult breeding males, respectively. Our methods and findings advance the knowledge of baleen whale physiology, can help guide future research on whale physiology and can inform population management and conservation efforts regarding minimizing the impact of anthropogenic stressors on whales.

Negligible hormonal response following dehorning in free-ranging white rhinoceros (Ceratotherium simum).

The white rhinoceros (Ceratotherium simum) is experiencing unsustainable poaching losses fuelled by a demand for horn. Increasingly, private and state reserves are dehorning their rhinoceros populations in an attempt to reduce poaching pressure. Rhinoceroses use their horns in social interactions as well as during resource access and so its partial removal as part of reserve management practices may adversely influence these behaviours. Physiological stress can correlate with animal welfare, reproductive state and health and thus acts as a useful indicator of these parameters. To establish whether dehorning causes a physiological stress response, glucocorticoid and gonadal steroid profiles of free-ranging white rhinoceroses were determined through the collection and analysis of faecal steroid metabolites before and after dehorning. Faecal corticoid profiles were not influenced by the number of occasions a rhinoceros had been dehorned or by the number of days that had elapsed since dehorning. Furthermore, there was no apparent suppression in the concentrations of testosterone or progesterone metabolites in males and females, respectively, after exposure to multiple dehorning procedures. These findings should increase wildlife managers' confidence that dehorning does not negatively impact white rhinoceros physiology as measured hormonally.

Exposure of managed red river hogs (Potamochoerus porcus) to urine from males stimulates estrous cycling and modulates fecal sex steroid metabolites in males and females

For unknown reasons, reproductive success varies among zoos in managed red river hogs. In response to urine exposure from novel conspecifics, we hypothesized that males with low libido would exhibit increased concentrations of testosterone metabolites and that acyclic and/or non-breeding females would be induced to cycle or cycle more regularly. Estrous cycle length and progesterone metabolites in same-sex housed females were compared prior to and following exposure to novel red river hog male urine. Male testosterone metabolites and female progesterone metabolites as well as estrous cycle length were compared among: 1) proven-breeder females and males; 2) non-breeding females newly paired with novel males; 3) non-breeding females and males exposed to urine from novel females and males. Fecal samples were collected 3–5 times per week for eight to 12 months, lyophilized, extracted, and assayed for progesterone and testosterone metabolites with validated enzyme immunoassays. Introduction of female urine resulted in an increased number of estrous cycles per female per month, and decreased luteal and increased follicular progesterone metabolites in females. Introduction of male urine resulted in an increase in testosterone metabolites in males. Average progesterone metabolites for pregnant proven-breeder females were more than double that for pregnant females newly paired to novel males. An interaction between season and treatment group, as well as the acyclicity of females from July through November irrespective of treatment group, suggest that season may confound and warrant judicious interpretation of the results. Additionally, females housed with pregnant females were either acyclic or did not carry their pregnancies to term, indicating that reproductive suppression may occur in females. In conclusion, urine may be a cost-effective and efficient means to manipulate estrous cycling in managed red river hogs. Furthermore, careful consideration of the number of females in a managed herd is recommended to avoid reproductive suppression.

Assisted reproductive technologies for endangered species conservation: developing sophisticated protocols with limited access to animals with unique reproductive mechanisms.

Assisted reproductive technologies (ARTs) have been proposed as a means of overcoming the significant challenges of managing small, isolated populations of endangered species in zoos. However, efficient protocols for ARTs do not exist for most endangered species. This review will focus on research efforts to characterize unique reproductive mechanisms and develop species-specific ARTs. Central to these studies are assays to measure steroid metabolites in urine or feces and/or training programs to allow unrestrained blood collections and ultrasound evaluations. The resulting information about estrous cycle dynamics, combined with studies of semen collection and processing, provides the foundation for the development of artificial insemination (AI). In vitro fertilization and embryo transfer are also discussed in relation to the advantages these techniques could provide relative to AI, as well as the significant challenges involved with technologies that require oocytes and embryos. Finally, an argument is made for additional research of nontraditional model species (e.g., domestic cats and dogs) and the development of novel models representing unique taxa. Whether these species are studied by zoo-based researchers with the expressed intent of developing ARTs for conservation or academic scientists interested in basic biology, the resulting information will provide a unique, evolutionary perspective on reproduction that could have wide-reaching benefits. The more information we have available, the better our chances will be of developing effective ARTs and making a difference in conservation efforts for endangered species.

Enzyme immunoassays for water-soluble steroid metabolites in the urine and feces of Japanese macaques (Macaca fuscata) using a simple elution method.

A simple, non-alcoholic extraction method for measuring estrogen and progesterone metabolites in excreta using enzyme immunoassays (EIAs) was developed in Japanese macaques. The obtained detection limits of EIAs using estrone conjugates (E1C), pregnanediol glucuronide (PdG), and estriol glucuronide (E3G) polyclonal antibodies with cross-reactivity to urinary and fecal steroid metabolites were 6.6 pg/ml, 2.1 ng/ml and 0.35 ng/ml, respectively. These assays allowed the determination of E1C, PdG, and E3G from the excreta with good reproducibility and accuracy. Thereafter, urine and fecal samples of two menstrual cycles and six pregnancies from eight female Japanese macaques were assayed. A typical increase in urinary and fecal E1C in follicular phase and PdG in luteal phase were shown during non-conceptive menstrual cycles. Urinary E3G levels also showed a preovulatory increase; however, fecal E3G levels were very low throughout the non-conceptive menstrual cycles. Levels of E1C and PdG in the urine and feces of pregnant females were gradually increased until parturition, while fecal E3G levels were low and reached detectable levels after the mid-pregnancy period. Although the extraction rate of estrogen and progestogen metabolites by our method was lower compared to those of the previous extraction method using an alcohol-containing buffer, our method was simple, and the correlation coefficients for the relationship between two methods were found to be statistically significant. The results presented here are of great practical value for a non-invasive method of monitoring ovarian function and pregnancy in Japanese macaques.

Integrating trans-abdominal ultrasonography with fecal steroid metabolite monitoring to accurately diagnose pregnancy and predict the timing of parturition in the red panda (Ailurus fulgens styani).

Red pandas (Ailurus fulgens styani) exhibit a variable gestation length and may experience a pseudopregnancy indistinguishable from true pregnancy; therefore, it is not possible to deduce an individual's true pregnancy status and parturition date based on breeding dates or fecal progesterone excretion patterns alone. The goal of this study was to evaluate the use of transabdominal ultrasonography for pregnancy diagnosis in red pandas. Two to three females were monitored over 4 consecutive years, generating a total of seven profiles (four pregnancies, two pseudopregnancies, and one lost pregnancy). Fecal samples were collected and assayed for progesterone (P4) and estrogen conjugate (EC) to characterize patterns associated with breeding activity and parturition events. Animals were trained for voluntary transabdominal ultrasound and examinations were performed weekly. Breeding behaviors and fecal EC data suggest that the estrus cycle of this species is 11-12 days in length. Fecal steroid metabolite analyses also revealed that neither P4 nor EC concentrations were suitable indicators of pregnancy in this species; however, a secondary increase in P4 occurred 69-71 days prior to parturition in all pregnant females, presumably coinciding with embryo implantation. Using ultrasonography, embryos were detected as early as 62 days post-breeding/50 days pre-partum and serial measurements of uterine lumen diameter were documented throughout four pregnancies. Advances in reproductive diagnostics, such as the implementation of ultrasonography, may facilitate improved husbandry of pregnant females and allow for the accurate prediction of parturition.

Excretion and measurement of corticosterone and testosterone metabolites in bank voles (Myodes glareolus)

The bank vole is a commonly used model species in behavioral and ecophysiological studies. Thus, presenting a validated method for noninvasive monitoring of corticosterone and testosterone secretion is of high relevance. Here, we evaluated the effect of time of day and an ACTH challenge test on measured fecal corticosterone (FCM) and testosterone (FTM) metabolites in both sexes. Furthermore, we performed radiometabolism experiments for both steroids and sexes to study metabolism and excretion of 3H-corticosterone and 3H-testosterone. FCM and FTM were analysed with a 5α-pregnane-3β,11β,21-triol-20-one enzyme immunoassay (EIA) and a testosterone (measuring 17β-hydroxyandrostanes) EIA, respectively. Males had significantly higher FCM levels than females and their main excretion route was via the feces (∼72%), whereas females excreted nearly equal portions in both feces and urine. For testosterone the main excretion route was via the feces in both sexes (∼80%). The time course of excretion was similar in both sexes, but for the first time a significant difference between injected steroids was found: Corticosterone was excreted faster than testosterone, both in urine (median of peak levels: 4h vs 6h) and feces (6h vs 8h). Several metabolites were present in the feces and the tested EIAs reacted with some of them. Time of day had a significant effect on measured fecal steroid metabolites. As expected, males had significantly higher FTM levels than females. ACTH administration significantly increased FCM values; peaks were observed 4–8h after injection. In conclusion, both tested EIAs proved suited for a noninvasive measurement of glucocorticoids and androgens in bank voles.

Validation of a field-friendly extraction and storage method to monitor fecal steroid metabolites in wild orangutans.

Measuring hormone metabolites from feces is the most often used method to assess hormonal status in wildlife. Although immediate freezing of fecal samples collected in the field is the best method to minimize the risk of degradation of hormones over time, this is often not possible in remote field sites. Therefore, alternative storage and preservation methods for fecal samples are required in these conditions. We conducted an experiment to investigate if fecal glucocorticoid (FGCM) and progesterone metabolite (pregnanediol-3-glucuronide; PdG) levels measured from samples that were extracted with a simple, field-friendly methodology correlate with those generated from frozen samples. We also evaluated whether storing fecal samples in alcohol is a suitable alternative to preserve FGCM and PdG concentrations long-term (i.e. over a 9-month period) at locations where fecal extraction is not feasible. Finally, we tested if the hormone concentrations in unpreserved fecal samples of orangutans change over 14h when stored at ambient conditions, representing the maximum duration between sample collection and return to the camp. FGCM and PdG levels measured from samples that were extracted with the field-friendly method showed strong correlations with those generated from frozen samples, and mean levels did not differ significantly between these methods. FGCM concentrations showed no significant change compared to control samples when fecal samples were stored for up to 6months in alcohol at ambient temperature and PdG concentrations even remained stable for up to 9months of storage. FGCM concentrations of fecal samples kept at ambient temperature for up to 14h post-defecation did not significantly differ compared to control samples frozen immediately after collection. These results provide the basis for the successful monitoring of the physiological status of orangutans living in remote natural settings, like those included in the Indonesian reintroduction programs.

Puberty, ovarian cycle, pregnancy, and postpartum ovulation in captive Sichuan golden monkeys (Rhinopithecus roxellana) based on changes in urinary and fecal gonadal steroid metabolites

The purpose of this study was to evaluate the reproductive status and clarify the reproductive physiology of captive Sichuan golden monkeys. The concentrations of urinary estradiol-3-glucuronide (E2G) and pregnanediol-glucuronide (PdG) or fecal estradiol-17β (E2) and PdG in two females, and fecal testosterone concentrations in a male, were measured continuously using enzyme immunoassays. On the basis of these hormone profiles, the follicular phase, luteal phase, and ovarian cycle were calculated to be 14.7 ± 4.8, 10.4 ± 2.8, and 25.1 ± 3.3 days, respectively. The first ovulation (puberty) in a female monkey was observed at 5.1 years old, and the first pregnancy was diagnosed at 6.4 years old. For the first 2 months of pregnancy (204 days), fecal E2 and PdG maintained constant high values and then increased until parturition. These profiles were similar to urinary E2G and PdG changes. During the last trimester of a twin pregnancy, fecal PdG was up to approximately three times higher compared with a single pregnancy. Therefore, fecal PdG levels in late pregnancy may be effective for the detection of a twin pregnancy. The first postpartum ovulation occurred 66 (fetal death and artificial rearing), 143 (fetal death), and 189 (natural suckling) days after parturition. The anovulation period of the natural suckling case was longer than the others. Conception and postpartum ovulation were detected between September and January. Fecal testosterone levels of the male were correlated with the fecal E2 level of the nonpregnancy period in exhibited together female. Our results reported that urinary (E2G and PdG) and fecal (E2 and PdG) hormone measurement is effective for monitoring the reproductive status, thereby expanding knowledge of the reproductive endocrinology of this endangered species.

Excretion patterns of coccidian oocysts and nematode eggs during the reproductive season in Northern Bald Ibis (Geronticus eremita).

Individual reproductive success largely depends on the ability to optimize behaviour, immune function and the physiological stress response. We have investigated correlations between behaviour, faecal steroid metabolites, immune parameters, parasite excretion patterns and reproductive output in a critically endangered avian species, the Northern Bald Ibis (Geronticus eremita). In particular, we related haematocrit, heterophil/lymphocyte ratio, excreted immune-reactive corticosterone metabolites and social behaviour with parasite excretion and two individual fitness parameters, namely, number of eggs laid and number of fledglings. We found that the frequency of excretion of parasites’ oocysts and eggs tended to increase with ambient temperature. Paired individuals excreted significantly more samples containing nematode eggs than unpaired ones. The excretion of nematode eggs was also significantly more frequent in females than in males. Individuals with a high proportion of droppings containing coccidian oocysts were more often preened by their partners than individuals with lower excretion rates. We observed that the more eggs an individual incubated and the fewer offspring fledged, the higher the rates of excreted samples containing coccidian oocysts. Our results confirm that social behaviour, physiology and parasite burden are linked in a complex and context-dependent manner. They also contribute background information supporting future conservation programmes dealing with this critically endangered species.

Assessment of ovarian activity in captive goral (Naemorhedus griseus) using noninvasive fecal steroid monitoring

To date, there is no information on gonadal steroidogenic activity of female goral (Naemorhedus griseus), a threatened species of Thailand. Captive goral populations have been established to produce animals for ex situ conservation and reintroduction, but as yet none are self-sustaining. The objectives of the present study were to (1) determine the influence of season on ovarian steriodogenic function; and (2) examine the relationship between gonadal hormone excretion and sexual behaviors throughout the year. Fecal samples were collected 5 to 7 days/wk for 15 months from 8 adult females housed at Omkoi Wildlife Breeding Center in Thailand and analyzed for ovarian steroid metabolites using validated enzyme immunoassays. Observations of sexual behaviors and mating were conducted each morning for 30 min/session. Based on fecal estrogen and progestagen metabolite concentrations, the overall estrous cycle length was about 21 days, with a 2- to 3-day follicular phase and an 18- to 20-day luteal phase. Sexual behaviors, most notably tail-up, increased for 2 to 3 days during the time estrogens were elevated during mating. Fecal progestagens were elevated during luteal phases and increased further during gestation, which lasted approximately 7 months. The lactation period was 5 months, and females were anestrus for 2 to 5 of those months, with the exception of one that cycled continuously throughout. Two females conceived around 2 months postpartum and so were pregnant during lactation. Birth records over the past 21 years indicated young are born throughout the year. This combined with the hormonal data suggests that female gorals are not strongly seasonal, at least in captivity, although there was considerable variation among females in estrogen and progestagen patterns. In conclusion, fecal steroid metabolite monitoring is an effective means of assessing ovarian function in this species and will be a useful tool for breeding management and planned development of assisted reproductive techniques such as artificial insemination and embryo transfer.

Identification of Fecal Sex Steroid Metabolites and Evaluation of Ovarian Cycle and Pregnancy in Somali Wild Ass (Equus africanus somaliensis)

Identification of Fecal Sex Steroid Metabolites and Evaluation of Ovarian Cycle and Pregnancy in Somali Wild Ass (Equus africanus somaliensis)

Evaluation of the fecal steroid concentrations inAlouatta belzebul(Primates,Atelidae) in theNationalForest ofTapirape‐Aquiri inPará,Brazil

The studies on fecal steroid metabolites published with free-living primates are limited mainly by the difficulty in obtaining samples. A radioimmunoassay was used to measure the fecal steroid concentrations in Alouatta belzebul in the National Forest of Tapirape-Aquiri in Brazil. Androgens were significantly higher for the adult males from the Area of Influence (AI-I group) when compared to those from the Control Area (CA group) (P < 0.05). Progestin and estrogen concentrations were higher in the females from the CA group than in those from the AI-I for both the adult females and females with offspring; however, P < 0.05 was only observed in the concentrations of fecal progestins from the adult females. The physiological differences between the AI-I and CA groups suggest that the cause was a sum of factors, such as an exposure to sound waves, feeding habits, daily activity patterns, and the habituation of the animals.

Faecal steroid metabolites assay as a non-invasive monitoring of reproductive status in animals

Measurement of faecal steroids as a non-invasive technique is widely used to monitor reproductive hormones in captive and free-ranging wild animals. This method offers a great advantage over invasive techniques like blood collection and deserves to be used in domestic animals. Repeated blood sampling is stressful, having animal welfare issues, difficult to obtain in field condition. In the faeces of cow, estradiol 17-α predominated, whereas in mares and sows, estradiol 17-β and estrone are main estrogens. Steroids are metabolized in liver, excreted in faeces and extraction is done by using a variety of methods such as ethanol, methanol etc. Faecal estrogen and progesterone metabolites evaluations are wel1 established approaches for monitoring of reproductive functions in a variety of mammalian species. So in future this method may be the most suitable for monitoring of reproductive status in farm animals particularly under field conditions.

Oral Progestin Priming Increases Ovarian Sensitivity to Gonadotropin Stimulation and Improves Luteal Function in the Cat1

As the only domesticated species known to exhibit both induced and spontaneous ovulation, the cat is a model for understanding the nuances of ovarian control. To explore ovarian sensitivity to exogenous gonadotropins and the influence of progestin priming, we conducted a study of queens that were down-regulated with oral progestin or allowed to cycle normally, followed by low or high doses of equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG). Our metrics included 1) fecal steroid metabolite profiles before and after ovulation induction, 2) laparoscopic examination of ovarian follicles and corpora lutea (CL) on Days 2 and 17 (Day 0 = hCG administration), and 3) ovariohysterectomy (Day 17) to assess CL progesterone concentrations, morphometrics, and histology. Reproductive tracts from time-matched, naturally mated queens (n = 6) served as controls. Every progestin-primed cat (n = 12) produced the desired response of morphologically similar, fresh CL (regardless of eCG/hCG dose) by Day 2, whereas 41.7% of unprimed counterparts (n = 12) failed to ovulate or had variable-aged CL suggestive of prior spontaneous ovulation (P < 0.05). The ovarian response to low, but not high, eCG/hCG was improved (P < 0.05) in primed compared to unprimed cats, indicating increased sensitivity to gonadotropin in the progestin-primed ovary. Progestin priming prevented hyperelevated fecal steroid metabolites and normalized CL progesterone capacity, but only when combined with low eCG/hCG. However, priming failed to prevent ancillary CL formation, smaller CL mass, or abnormal luteal cell density, which were common to all eCG/hCG-treated cats. Thus, the domestic cat exposed to eCG/hCG produces CL with structural and functional aberrations. These anomalies can be partially mitigated by progestin priming, possibly due to a protective effect of progestin associated with enhanced ovarian sensitivity to gonadotropins.