Theriogenology wild最新文献

{"title":"The effect of extended cold storage and the use of extenders on motility and swimming kinematics of shortnose sturgeon sperm","authors":"Kenzie H. Melanson ,&nbsp;Matthew K. Litvak","doi":"10.1016/j.therwi.2025.100144","DOIUrl":"10.1016/j.therwi.2025.100144","url":null,"abstract":"<div><div>Shortnose sturgeon (<em>Acipenser brevirostrum</em>) are listed as a species of special concern in Canada and as endangered in the US. Increasing knowledge about the reproductive biology of this species will aid in the development of assisted reproduction protocols. However, access to wild sperm is limited, so short-term and long-term storage of sperm from sturgeon is crucial for reproductive studies. Milt samples were collected from wild shortnose sturgeon caught in the Wolastoq River, New Brunswick, Canada. Subsets of semen were mixed with different extenders with or without oxygen; control treatments without extenders were also run. We used computer-assisted sperm analysis (CASA) to determine sperm motility and swimming kinematics for the different treatments. All groups were examined immediately after collection and treatment application, and then 1, 2, and 7 days after storage in a fridge (4 °C) for experiment 1, and days 1, 3, 7, 10, 14, 17, 21, and 24 for experiment 2. Motility, curvilinear velocity, linearity, and wobble showed an overall decrease over time, and there was no significant effect of oxygen. Milt treated with the Park and Chapman extender had the slowest motility decline of extenders used (41.21 % in 2022 and 47.09 % in 2023) after 7 days, but only maintained motility up to day 10. While untreated milt maintained some motility up to day 21, milt treated with the modified Tsvetkova extender remained motile for up to 24 days (&lt; 5 %), and had less potential for contamination, making the modified Tsvetkova extender the most practical extender choice.</div></div>","PeriodicalId":75220,"journal":{"name":"Theriogenology wild","volume":"8 ","pages":"Article 100144"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effectiveness of washing procedures for removing Brucella abortus from in vivo- and in vitro-derived wood bison embryos","authors":"Miriam P. Cervantes ,&nbsp;J. Manuel Palomino ,&nbsp;Muhammad Anzar ,&nbsp;Brenda J. Allan ,&nbsp;Gabriela F. Mastromonaco ,&nbsp;Gregg P. Adams","doi":"10.1016/j.therwi.2026.100158","DOIUrl":"10.1016/j.therwi.2026.100158","url":null,"abstract":"<div><div>Washing procedures for zona pellucida (ZP)–intact bovine embryos have been developed to enable international movement of pathogen-free embryos. We evaluated the effectiveness of a washing procedure to remove <em>Brucella abortus</em> from <em>in vivo</em>– and <em>in vitro</em>–produced bison embryos exposed to the pathogen <em>in vitro</em>. In Experiment 1, ZP-intact embryos from superovulated bison were incubated with <em>B. abortus</em> biovar 1 (1.9 × 10⁵ to 3.8 × 10⁸ CFU/mL) for 2 h at 37ºC. Embryos underwent a 10-step wash using medium (PBS + 0.4% BSA) with or without antibiotics (penicillin and streptomycin). Medium samples were cultured after washes 1, 3, 6, and 9, and embryos were individually cultured on blood agar after the final wash. <em>B. abortus</em> was not detected in samples after the third wash in either group. PCR detected <em>B. abortus</em> in 2/27 embryos washed without antibiotics, but in none of those washed with antibiotics (0/27). In Experiment 2, cumulus-oocyte complexes were collected from superstimulated bison 34 h after hCG treatment, fertilized <em>in vitro</em> immediately, and cultured for 7 days. ZP-intact embryos were exposed to <em>B. abortus</em> and washed as in Experiment 1. <em>B. abortus</em> was not detected in samples after wash 3, and all embryos were culture-negative (0/84). In summary, <em>B. abortus</em> was detected only in <em>in vivo</em>-derived embryos washed without antibiotics (2/27), whereas no positives were observed in embryos washed with antibiotics or <em>in vitro</em>-derived embryos. Washing effectively removed <em>B. abortus</em> from <em>in vivo</em>- and <em>in vitro</em>-derived wood bison embryos, but disease-free calf production remains unconfirmed.</div></div>","PeriodicalId":75220,"journal":{"name":"Theriogenology wild","volume":"8 ","pages":"Article 100158"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148167615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lessons from 15 years of wood bison (Bison bison athabascae) ARTs at Toronto Zoo","authors":"M.A.M.M. Ferraz,&nbsp;P. Mackie,&nbsp;G.P. Adams,&nbsp;G.F. Mastromonaco","doi":"10.1016/j.therwi.2026.100170","DOIUrl":"10.1016/j.therwi.2026.100170","url":null,"abstract":"<div><div>Over the past 15 years, the Toronto Zoo has undertaken a sustained program to develop, implement, and refine assisted reproductive technologies (ARTs) for the threatened wood bison (<em>Bison bison athabascae</em>). We review the outcomes of estrus synchronization and artificial insemination trials between 2010 and 2021, highlighting both technical milestones and persistent challenges. Protocols were adapted from those used for domestic cattle after iterative modification to address species-specific reproductive physiology, seasonal breeding, stress sensitivity, and logistical challenges. Across the study period, these efforts produced 14 calves, including the first reported pregnancies in wood bison from sex-sorted semen and sperm cryopreserved for 35 years. However, success rates were constrained by small sample sizes, variable recipient availability, and inconsistent responses to hormone protocols. By documenting both advances and limitations, this work demonstrates the feasibility of long-term ART programs in wildlife conservation, the critical role of zoological institutions in sustaining them, and the importance of continued refinement in hormone protocols, semen cryopreservation techniques, and recipient management to improve reproductive outcomes in threatened species.</div></div>","PeriodicalId":75220,"journal":{"name":"Theriogenology wild","volume":"9 ","pages":"Article 100170"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148569142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semen characteristics, handling of a highly viscous ejaculate, and exploratory cryopreservation attempts in free-ranging peri-urban giant anteaters (Myrmecophaga tridactyla)","authors":"Janaina Torres Carreira,&nbsp;Diego Alaska Almeida,&nbsp;Gracila Heitor de Oliveira,&nbsp;Sebastian Kirchhof,&nbsp;Tatiana Morosini de Andrade Cruvinel","doi":"10.1016/j.therwi.2026.100171","DOIUrl":"10.1016/j.therwi.2026.100171","url":null,"abstract":"<div><div>The giant anteater (<em>Myrmecophaga tridactyla</em>) is a vulnerable xenarthran with a wide geographic distribution across South and Central America. Reproductive data for this species remain scarce, particularly from free-ranging individuals in anthropogenically modified landscapes. This exploratory study describes semen characteristics and cryopreservation trials in free-ranging peri-urban giant anteaters admitted to a wildlife hospital following vehicle collisions or wildfire burns in São Paulo state, Brazil. Five adult males were assessed; median body mass was 35.80 kg (IQR 3.75), body temperature 34.5 °C (IQR 0.30), and haematocrit 30.4% (IQR 4.30). Semen was collected by electroejaculation in four of the five animals, the day after the admission. All samples were markedly viscous (grade 4/4), and five viscosity-reduction methods were compared descriptively; filtration followed by fine-needle aspiration performed best in this small sample size condition. Median seminal volume was 8.5 mL (IQR 10.5), progressive motility 25.0% (IQR 31.25), and sperm concentration 126.0 × 10⁶ sptz/mL (IQR 77.63), while total morphological defects reached 83.54% (IQR 17.81). Two samples were cryopreserved using a commercial egg yolk-Tris based extender (BotuBov®) containing 6.4% glycerol. Post-thaw evaluation revealed progressive motility of 5% in one sample, while no motile spermatozoa were recovered from the remaining one. These results document the challenges of cryopreserving giant anteater semen using a bovine extender and highlight the need for species-specific protocols. Despite the poor cryo-survival, this study contributes baseline reproductive data from an underrepresented context, free-ranging, injured, peri-urban individuals, and showcases the possibility of opportunistic semen collection for building germplasm banks for this threatened species.</div></div>","PeriodicalId":75220,"journal":{"name":"Theriogenology wild","volume":"9 ","pages":"Article 100171"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148569211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fecal progestagen analysis in Lord Derby’s eland (Taurotragus derbianus) with lack of biological relevance: The importance of physiological validation","authors":"Linda M. Penfold ,&nbsp;Martine de Wit ,&nbsp;Kat Mowle","doi":"10.1016/j.therwi.2026.100162","DOIUrl":"10.1016/j.therwi.2026.100162","url":null,"abstract":"<div><div>Fecal samples were collected from six adult female Lord Derby’s eland (<em>Taurotragus derbianus</em>) to assess ovarian activity. Fecal samples were extracted using an ethanol-based extraction method and a sub-set of samples was extracted using enzyme hydrolysis with β-glucuronidase/arylsulfatase to target glucuronide-conjugated steroid metabolites. Analysis of fecal progestagens using an antibody to pregnanediol glucuronide in four females maintained without a breeding male over one year did not reveal any clear cycling activity or seasonal changes, and fecal progestagen concentrations remained unaffected following treatment with two prostaglandin injections. Similarly, luteal cycles were absent in the fecal progestagen analysis of two female Lord Derby’s elands before and after introduction of a breeding bull. A pregnancy confirmed by birth of a calf was undetected by a measured increase in fecal progestagen concentrations. Progestagen profiles from fecals treated using two extraction methods were significantly correlated (r = 0.628; P &lt; 0.001). In conclusion, an antibody to pregnanediol glucuronide did not reflect ovarian activity in female Lord Derby’s eland and enzyme digestion that was predicted to cleave purported metabolites to native progesterone failed to change the pattern of the profile. The present study demonstrates the importance of antibody selection and understanding of excretory pathways and especially the incorporation of physiological data into the validation process of hormone assays for individual species.</div></div>","PeriodicalId":75220,"journal":{"name":"Theriogenology wild","volume":"8 ","pages":"Article 100162"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148167660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Medical management of metritis secondary to retained fetal membranes in a linne’s two-toed sloth (Choloepus didactylus): A case study","authors":"Monica Lee ,&nbsp;Jessica Y. Heinz ,&nbsp;Jennifer Nollman ,&nbsp;Michael R. Wenninger ,&nbsp;Julie L. Barnes","doi":"10.1016/j.therwi.2026.100154","DOIUrl":"10.1016/j.therwi.2026.100154","url":null,"abstract":"<div><div>An 11-year-old multiparous female Linne’s two-toed sloth (<em>Choloepus didactylus</em>) became lethargic and hyporexic eight days after an uncomplicated delivery of a single healthy offspring. She was treated with intramuscular (IM) injections of ceftiofur crystalline free acid (6.2 mg/kg) and meloxicam (0.1 mg/kg). The next day, the female was immobilized for examination, including transvaginal hysteroscopy, which revealed a marked amount of purulent vaginal and uterine fluid, as well as suspected retained fetal membranes. Treatment included uterine saline lavage and antibiotic infusion (ceftiofur sodium, 1 g), intravenous (IV) enrofloxacin (5 mg/kg for two days), oral broad-spectrum antibiotics (enrofloxacin, 10 mg/kg once daily for ten days and amoxicillin/clavulanic acid, 14 mg/kg twice daily for fourteen days), misoprostol (9.5 µg/kg orally once daily for six days), oxytocin (0.15 IU/kg IM once daily for five days), and supportive care. Culture from the uterine lavage revealed <em>Enterococcus faecalis</em> (3 +), <em>Bacteroides</em> sp. (3 +), and <em>Peptostreptococcus</em> sp. (2 +). Due to difficulty with oral administration, antibiotics were switched to penicillin G procaine (40,000 IU/kg IM) for an additional seventeen days. Four weeks post-initial exam, recheck hysteroscopy revealed moderate white mucoid discharge and adherent placental tissue. Repeat uterine lavage cultured <em>Acinetobacter</em> sp. (1 +) and <em>Enterococcus faecalis</em> (1 +); supportive care was continued for eight additional days. Eight weeks after initial presentation, the patient was asymptomatic and considered clinically recovered. This report represents the first documentation of medically managed retained fetal membranes and secondary metritis in a Linne’s two-toed sloth.</div></div>","PeriodicalId":75220,"journal":{"name":"Theriogenology wild","volume":"8 ","pages":"Article 100154"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147600100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro maturation and fertilization of oocytes obtained by gamete rescue from a dama gazelle (Nanger dama) calf","authors":"Erin M. Saylor,&nbsp;James D. Gillis,&nbsp;Emily Brenner,&nbsp;Linda M. Penfold","doi":"10.1016/j.therwi.2026.100173","DOIUrl":"10.1016/j.therwi.2026.100173","url":null,"abstract":"<div><div>The dama gazelle (<em>Nanger dama</em>) has been extirpated from most of the species’ native range primarily due to overhunting and anthropogenic habitat disturbance. Population protection paired with propagation in managed care and reintroduction has avoided complete extinction of the species, but continued anthropogenic disturbance and low population connectivity hinder the natural recovery of dama gazelles <em>in situ</em>. Continued recovery relies heavily on <em>ex situ</em> conservation actions, which are facilitated by basic understanding of the species’ reproductive biology. In non-domestic species such as the dama gazelle, research on reproductive biology is limited. Gamete rescue can provide opportunities to learn about reproductive biology in endangered species. In this study, ovaries recovered via gamete rescue from a juvenile dama gazelle were processed to recover oocytes (n = 15) for in vitro maturation and fertilization using two commercially available Stroebech media; Small Ruminant and Bovine media. Oocyte maturation assessed by Hoechst 33342 staining was achieved in both media while cleavage was observed in Small Ruminant media only (n = 2). Initial results are promising for development of a gamete rescue protocol for dama gazelle.</div></div>","PeriodicalId":75220,"journal":{"name":"Theriogenology wild","volume":"9 ","pages":"Article 100173"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148736752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro embryo production in the Iberian lynx (Lynx pardinus) using oocytes recovered post-mortem and cryopreserved spermatozoa","authors":"Andrea Priego-González ,&nbsp;Ana Munoz-Maceda ,&nbsp;Raquel González ,&nbsp;Juan Antonio Rielo ,&nbsp;Natalia Gañán ,&nbsp;Ana Sanchez-Rodriguez ,&nbsp;Pilar Villar-Moya ,&nbsp;Ana Cantos Rubert ,&nbsp;María Jesús Sánchez-Calabuig ,&nbsp;Eduardo R.S. Roldan","doi":"10.1016/j.therwi.2025.100142","DOIUrl":"10.1016/j.therwi.2025.100142","url":null,"abstract":"<div><div>The Iberian lynx (<em>Lynx pardinus</em>), once considered the most endangered felid in the world, has become a remarkable example of conservation success thanks to intensive <em>ex situ</em> and <em>in situ</em> management efforts. However, the long-term viability of the species remains under threat. The implementation of assisted reproductive technologies (ARTs) would contribute to ensure the species viability, but the use of ARTs is limited in this species and there are still important gaps in the knowledge of its physiology. Here, we report the first <em>in vitro</em> fertilization (IVF) and early embryo development in the Iberian lynx using oocytes retrieved post-mortem and cryopreserved spermatozoa. Oocytes from six females were subjected to <em>in vitro</em> maturation using two sets of conditions. In the first series, oocytes incubated <em>in vitro</em> for 24 h, exhibited a very low proportion (0–37 %) reaching metaphase II (MII). Attempted IVF with cryopreserved spermatozoa resulted in no fertilization. In a second series, oocytes were incubated <em>in vitro</em> for 28 h; grade I-II oocytes exhibited 40 % maturation rate (MII), whereas grade III oocytes showed 28 % maturation rate. Matured oocytes from one female were co-incubated with cryopreserved sperm for 18 h resulting in cleavage rates of 39.3 % (grade I–II) and 7.1 % (grade III) and the opportunity to vitrify one blastocyst and six morulae. These results demonstrate the feasibility of using ARTs in this species, validating domestic cat protocols for Iberian lynx gametes, and providing a foundation for further refinement of IVF protocols, embryo cryopreservation, and ultimately, embryo transfer strategies for use in conservation programs.</div></div>","PeriodicalId":75220,"journal":{"name":"Theriogenology wild","volume":"8 ","pages":"Article 100142"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145698085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monthly plasma oxytocin samples detect lactational but not social management or behavioral variation in ex situ black and white rhinoceroses","authors":"Drew M. Arbogast ,&nbsp;Elizabeth W. Freeman ,&nbsp;Elizabeth M. Donelan ,&nbsp;Marieke K. Jones ,&nbsp;Louisa A. Rispoli ,&nbsp;Terri L. Roth ,&nbsp;Lara C. Metrione","doi":"10.1016/j.therwi.2026.100155","DOIUrl":"10.1016/j.therwi.2026.100155","url":null,"abstract":"<div><div>The neuropeptide hormone oxytocin is essential for uterine contractions and lactation, facilitates reproductive and social behaviors, and may also regulate stress and psychological state. Plasma samples were collected monthly from black (<em>Diceros bicornis</em>; n = 19 males, 17 females) and white (<em>Ceratotherium simum</em>; n = 20 males, 40 females) rhinoceroses housed across 33 North American facilities. Focal animal behavioral observations were conducted twice, ∼6 months apart, for three to five days each time. Plasma oxytocin was extracted via proteomic reduction, alkylation, and precipitation methods. Successful analytical validation of the enzyme immunoassay consisted of a parallel displacement curve between serially diluted standards and pooled extracts, linearity across dilutions, and 96% recovery of spiked synthetic hormone. Monthly peripheral plasma oxytocin concentrations did not differ between black and white rhinoceroses but were positively associated with age in the former (<em>p</em> = 0.049). In lactating white rhinoceroses, oxytocin increased from 0 to 365 days postpartum (<em>p</em> &lt; 0.001), serving as a biological validation of the assay. There were no significant associations detected between oxytocin concentrations and other variables of interest: sex, pregnancy status, median group size, degree of social access, and rates of affiliative and agonistic behaviors (<em>p</em> &gt; 0.10). It is possible that more frequent sampling might better detect associations between oxytocin and transient social dynamics. This study provides the first data on oxytocin concentrations in black and white rhinoceroses and establishes a foundation for further investigations.</div></div>","PeriodicalId":75220,"journal":{"name":"Theriogenology wild","volume":"8 ","pages":"Article 100155"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147797839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advanced reproductive age is associated with changes in ovarian architecture and extracellular matrix composition in the South African cheetah (Acinonyx jubatus)","authors":"A. Heinrich,&nbsp;A. Futtner,&nbsp;C. Young,&nbsp;M. Takahashi,&nbsp;R.E. Burns,&nbsp;B. Durrant,&nbsp;E. Ruggeri,&nbsp;F.E. Duncan","doi":"10.1016/j.therwi.2026.100172","DOIUrl":"10.1016/j.therwi.2026.100172","url":null,"abstract":"<div><div>Cryopreservation of germplasms from endangered species offers a last line of defense against loss of genetic diversity. However, animals under human care live extended lifespans compared to wild counterparts, and our understanding of the influence of aging in endangered species is limited. Therefore, we used the South African cheetah (Acinonyx jubatus) as an ambassador species to understand the influence of age on follicle content and composition of the surrounding extracellular matrix. We performed histological analyses of formalin-fixed paraffin-embedded (FFPE) ovarian tissue from 11 cheetahs (3.85–14.75 years) formerly managed under the San Diego Zoo Wildlife Alliance (SDZWA). Ovarian follicles were visualized by H&amp;E and classified by stage. All follicle stages tended to decrease with age, with a significant decline observed in primordial follicles. We then used histochemical approaches to probe components of the ovarian microenvironment, including iron, elastin, hyaluronan (HA), and collagen I/III. Iron and elastin were enriched near follicles with abnormal morphology and multi-nucleated giant cell (MNGC)-like structures. HA localized throughout the ovary and tended to decrease with age in the tunica albuginea, cortex, and stroma. The tunica and medulla of the cheetah ovary were collagen-rich relative to the cortex. With age, collagen increased in the tunica albuginea and the cortex, whereas it decreased in the medulla. The age-associated increase in collagen was associated with thickening of the tunica. These data demonstrate hallmarks of ovarian aging in the cheetah and will inform how future protocols for follicle recovery from ovarian tissue may need to be tailored based on age of the individual.</div></div>","PeriodicalId":75220,"journal":{"name":"Theriogenology wild","volume":"9 ","pages":"Article 100172"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148635010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}