Non-invasive hormonal characterization of the ovarian cycle, pregnancy, and seasonal anestrus of the female addra gazelle (Nanger dama ruficollis)

Abstract

Non-invasive fecal hormone metabolite monitoring was used to characterize the estrous cycle, pregnancy, and seasonal anestrus of the critically endangered addra gazelle (Nanger dama ruficollis). With less than 250 animals remaining in the wild and ∼168 individuals managed in captivity, it is crucial to maintain sustainable populations. Progestogen and estrogen profiles were obtained from analysis of fecal samples collected approximately every other day, within varying intervals, over the course of 7 years (n = 8 adult females). Average estrous cycle length was 19.5 ± 0.4 days (range, 14-26 days), with a luteal phase length of 14.6 ± 1.2 days (range, 10-16 days), and an inter-luteal period of 5.2 ± 1.4 days (range, 2-7 days). Mean gestation length for six pregnancies was 200.7 ± 0.4 days (range, 200-202 days). Fecal progestogens increased at 12 weeks of gestation and remained elevated until parturition. Addra gazelle females exhibited a period of seasonal anestrus with consistently low progestogen concentrations and no cyclic activity from about September to March. Analysis of reproductive and climate records demonstrated a peak in U.S. births that coincided with maximal rainfall in the native habitat of the addra gazelle. Results show that estrous cycle, luteal phase, and inter-luteal phase lengths in addra are similar to those observed in other gazelle species, however, to our knowledge, this is the first study to demonstrate seasonal anestrus in the Nanger genus.

Immunohistological study of the unexplored vomeronasal organ of an endangered mammal, the dama gazelle (Nanger dama)

“…Enormous differences in the specific reproductive mechanisms exist across species, even among species that belong to the same phylogenetic clade (i.e., family; Wildt et al, 2001). Although certain aspects of dama gazelle reproductive biology have been established in preparation for the future implementation of assisted reproductive technology (Arregui et al, 2021;Pickard et al, 2001Pickard et al, , 2003Wojtusik et al, 2017), to our knowledge, no information exists regarding the role played by semiochemical-mediated communications in the sexual behavior and reproductive physiology of dama gazelle. Sexual attraction; mother-young interactions; estrus indication, induction and synchronization; puberty acceleration; postpartum anestrus; hormonal stimulation; and penile erections are all influenced by pheromones in ruminants (Archunan et al, 2014).…”

Exploring the vomeronasal organ in an endangered antelope species

“…A recent survey of 50 species concluded that there are as many mechanistic variations in reproduction as there are species (Wildt et al, 2010). Although certain aspects of the reproductive biology of the dama gazelle have been established in preparation for the future implementation of assisted reproductive technology (Pickard et al, 2001(Pickard et al, , 2003Wojtusik et al, 2017;Arregui et al, 2021), there is, to our knowledge, no information regarding the role of semiochemical-mediated communication in the sexual behavior and reproductive physiology of the dama gazelle. Sexual attraction, mother-young interactions, estrus indication, induction and synchronization, puberty acceleration, reducing the postpartum anestrus, hormonal stimulation, and enhancing the penis erection are some of the classical events influenced by pheromones in ruminants (Archunan et al, 2014).…”