Reproductive conditioning of captive lionesses: assessments of vaginal microbiota, oxidative stress and hormonal profile

Reproductive management in captive large felids represents a major challenge for zoological institutions and conservation programs. This descriptive and exploratory study investigated endocrine profile, oxidative status, and vaginal microbiota in seven captive African lionesses ( Panthera leo ) with different reproductive conditions: two intact cycling females, three females treated with a deslorelin (GnRH agonist) implant, and two ovariectomized females. During routine health checks under general anesthesia, blood samples and vaginal swabs were collected to assess serum anti-Müllerian hormone (AMH), estradiol, progesterone, oxidative stress markers (d-ROMs and BAP), and vaginal microbiota composition through 16S rRNA gene sequencing. AMH concentrations clearly differentiated intact lionesses from ovariectomized individuals, while implanted females showed intermediate AMH values. Estradiol and progesterone profiles supported effective pharmacological ovarian suppression in implanted lionesses. Oxidative markers showed inter-individual variability. Lionesses with endocrine profiles comparable with active ovarian function displayed higher d-ROMs values. Vaginal microbiota composition at the phylum level was heterogeneous across individuals, without consistent patterns uniquely associated with a specific reproductive condition. Overall, this study provides preliminary integrated data on endocrine, oxidative, and microbial parameters in captive lionesses. AMH may represent a useful tool for assessing ovarian status, while the observed variability in oxidative and microbial profiles warrants further investigation through larger, longitudinal, and functionally integrative studies. • Fertility in captive lionesses is managed by surgical or reversible contraception •Hormonal, oxidative and microbiota data provide a framework for reproductive monitoring •Oxidative stress showed a trend toward higher values in active lionesses • Vaginal microbiota showed high variability with no clear group association • Anti-Müllerian hormone effectively distinguished ovarian status in captive lionesses