Theriogenology wild最新文献

Cannibalism, or intraspecific predation, refers to the practice in which an individual completely or partially consumes another conspecific. Filial cannibalism occurs when parents consume their own offspring, whether they are alive or stillborn. This study describes filial cannibalism behavior in just one female of each species, Amazon rainbow boa (Epicrates cenchria) and the Caatinga rainbow boa (E. assisi). We observed that female E. cenchria and E. assisi only consumed atretic eggs. A female E. cenchria consumed two out of the eight atretic eggs she delivered, while sparing the four neonates and the only stillborn fetus in her litter. A female E. assisi consumed two out of the four atretic eggs and attempted to ingest the amniotic sacs and liquid yolk throughout the entire observation, sparing two neonates. This is the first documented record of such behavior in E. assisi.

Knowledge of pregnancy length and the physiological parameters during pregnancy is an important tool for pregnancy diagnosis in free-ranging and captive individuals and for the correct husbandry of captive pregnant females. Therefore, this study aimed to describe the progesterone pattern during pregnancy in T. inunguis and to estimate the pregnancy length in this species. Blood or urine samples from a total of eight pregnancies were collected from six captive female Amazonian manatees. Serum progesterone and urinary progesterone metabolites were measured by radioimmunoassay and enzyme immunoassay. The mean of serum progesterone throughout pregnancy was 5.17 ± 4.71 ng/ml (0.08–19.71 ng/ml) and the mean urinary progesterone metabolites concentration was 11.34 ± 12.28 ng/mg Cr (1.00 – 54.71 ng/mg Cr). A pregnancy length of approximately 12–13 months was observed (369.6 ± 27.2 days, range 352–401 days). The pregnancy length observed in this study falls within the range reported for other sirenians. During the first four months, there was a high level of progesterone. After that, the hormone levels began to decrease. Low progesterone levels during most of pregnancy were also observed in other sirenians. This hormonal pattern suggests the existence of the paracrine action of progesterone or the role of other hormones in the maintenance of pregnancy. However, further studies are necessary to clarify the pregnancy endocrinology in Amazonian manatees.

Sexual maturity and body condition are interconnected in many mammals. For non-domestic felids held in human care, the effect of body condition on male fertility has not been studied, although obesity is a recognized problem for many species such as the African lion (Panthera leo) under captive conditions.

Here, we assessed body weight, body condition via body condition score (BCS), reproductive organ appearance and size by ultrasonography and semen parameters as a function of age in a large population of captive male lions housed in different facilities in South Africa. Of 59 individuals (age range 2.5–10 years), we rated 21 (36 %) of the males (≥ 4 years) as highly obese (BCS 8–9). Semen collection via urethral catheter was successful in 49 males (83.0 %). Sperm were found in 44 males (74.6 %) across all age groups. Sperm motility and detailed sperm morphology was assessed in 42 and 18 lions, respectively.

As expected, body weight and reproductive organ size increased with age, but only the testis size increased in proportion to BCS. Although our data are unbalanced, as older animals (already after five years of age) were more often obese, they suggest an optimum age and body condition for potential fertility with adequate physical maturity in male lions. Physical maturity appeared to be reached between the ages of three and five years, which is later than sexual maturity in male lions.

Lions that far exceeded the normal body weight range and had a BCS of 8 or 9 had lower semen quantity and quality. Therefore, male lions in captivity are in prime breeding condition when physical maturity is combined with a BCS < 8.

Our data contribute towards interpretation of fertility assessments in managed breeding programs for lions. Ultrasonographic appearance of the reproductive organs, BCS and semen parameters can help to identify and select breeding males.

This case report discusses the pharmacological induction of parturition in a pacarana (Dinomys branickii), a rare South American rodent with a reproductive biology that is still poorly understood. The aim of this case report was to induce labor in a pacarana in the final third of gestation after fetal death was confirmed due to a maternal cardiopulmonary arrest lasting 4 min. Using a pharmacological protocol similar to that applied in ruminants, the induction of labor was successfully carried out, resulting in the expulsion of two dead fetuses 2 h and 15 min after the administration of cloprostenol (0.275 mg; im) and dexamethasone (4 mg; im). This case, the first documented instance of pharmacological induction in pacarana, underscores the efficacy of the procedure and the need for further research to understand the reproductive physiology of the species, potentially aiding in the conservation of this and other Hystricomorpha species.

The reproductive success of polar bears (Ursus maritimus) in U.S. zoos is poor and the underlying causes of reproductive failure remain elusive. It is evident that new methodologies for evaluating fertility are needed, along with baseline information about species-specific reproductive anatomy and physiology. Between 2012 and 2024, 25 examinations of 17 female polar bears were conducted opportunistically, and included vulvar measurements, vaginal cytology, vaginoscopy, hysteroscopy with endometrial biopsy, and/or ultrasonography. Additionally, reproductive tracts (n = 10) harvested post-mortem were examined shortly after collection, allowing for inspection of anatomy ex vivo. The outcomes of these activities yielded detailed measurements and descriptions of reproductive anatomy. Vaginal cytology patterns demonstrated shifts in vaginal epithelial cell type associated with estrus and vaginoscopy enabled systematic evaluation of internal reproductive structures, including the vestibule, vestibulo-vaginal junction, urethral os, vaginal canal, and cervix. Hysteroscopy allowed visualization of the uterine endometrium and facilitated endometrial biopsy collection. Additionally, ultrasonography was utilized to identify ovaries in several bears, offering insights into ovarian dynamics and follicular development. Several abnormalities were noted during examinations of both in vivo and ex vivo tracts; these included clitoral hypertrophy, vaginal strictures, uterine polyps, endometritis, and cystic hyperplasia, although it is unclear if these aberrations significantly impacted fertility. Findings contribute to a better understanding of polar bear reproductive anatomy, highlight the utility of diagnostic techniques for monitoring reproduction, and elucidate potential causes of reproductive failure in polar bears.

Decreased genetic diversity and possible inbreeding depression have recently been documented in the last wild ocelot (Leopardus pardalis) population in the United States. One consequence of inbreeding depression in felids may be reduced semen quality which can adversely affect reproductive potential. Detailed assessments of reproductive parameters in wild individuals and populations can be conducted using assisted reproductive technologies, such as semen collection and analysis. For most felid species, semen has traditionally been collected via electroejaculation (EEJ²); however, an alternative method has been developed using alpha-2 agonist drugs to induce direct sperm release into the urethra, allowing collection by catheterization without requiring specialized equipment. The goal of this study was to characterize normative reproductive traits in free-ranging ocelots and co-occurring bobcats (Lynx rufus) in southern Texas and assess the effectiveness of urethral catheterization (UC³) for semen recovery in both species. For semen collection, free-ranging cats were live-captured and anesthetized using intramuscular ketamine and medetomidine/dexmedetomidine (alpha-2 agonist) with UC conducted 20–40 minutes post-induction. In ocelots only, EEJ was subsequently performed if UC failed to recover a viable sample. Semen collection was attempted in 31 felids (n=9 ocelots; n=22 bobcats), with sperm recovery by UC in seven of nine ocelots (78 %) and 14 of 22 bobcats (66 %), and by EEJ in four of five ocelots (80 %). For ocelots, the percentage of primary morphologic abnormalities was higher (p<0.001) for UC (47.75 ± 6.7; mean ± SEM) compared to EEJ (9 ± 2.7) but percent normal morphology (MORPH) did not differ between UC and EEJ (p=0.218). In wild ocelots, seminal parameters appeared lower relative to historical values reported for zoo-managed ocelots, possibly related to reduced heterozygosity. In wild bobcats, seminal traits were inferior to those of ocelots but similar to reports for other zoo-managed Lynx species. In conclusion, detailed male reproductive traits have been characterized for the first time in wild, free-ranging ocelots and bobcats in southern Texas. Although UC allowed semen recovery for assessment of seminal traits in both species, EEJ produced higher quality samples in ocelots when applied after UC while also mitigating the adverse impact of urine contamination observed frequently with both collection methods.