Reproductive endocrine responses to photoperiod and exogenous gonadotropins in the pallas' cat (Otocolobus manul)

Abstract

Fecal samples were collected for 14-26 months from three male and six female Pallas' cats (Otocolobus manul) to examine gonadal steroidogenic activity in response to changes in photoperiod and treatment with exogenous gonadotropins. Females exhibited a seasonal anestrus from May-December, excreting consistently low concentrations of fecal estrogens (overall mean, 50.278.5 ng/g). During the breeding season (January-April), baseline fecal estrogen concentrations were higher, averaging 128.4718.9 ng/g, with peak concentrations ranging from 455.8-909.6 ng/g. Interpeak intervals in estrogen excretion ranged between 7 and 21 days, with an average estrous cycle length of 14.371.7 days. Two females became pregnant after natural mating, with overall luteal progestogen concentrations averaging B40 mg/g throughout gestation. Fecal estrogens increased in mid-gestation, peaking just before birth. Induction of follicular development with eCG (100-300 IU, i.m.) resulted in an increase in fecal estrogens (peak range, 263.1-1198.1 ng/g), followed by a postovulatory increase in fecal progestogens (overall mean, 41.1711.9 mg/g) after hCG (75-150 IU, i.m.). Despite apparently normal ovarian responses, none of the females conceived after artificial insemination (AI). The gonadotropin-induced nonpregnant luteal phase lasted 49.875.3 days (range, 30-60 days), whereas gestation lasted B70 days. In the male Pallas' cat, fecal androgens were elevated from November-April (overall ). Entrainment of seasonality to photoperiod was demonstrated by stimulation of gonadal steroidogenic activity in cats exposed to increasing artificial light during natural (nonbreeding season) and artificially induced short-day photoperiods. In summary, reproduction in Pallas' cats is highly seasonal and photoperiod-dependent. Females exhibit elevated baseline and peak fecal estrogen concentrations for 3-4 months during late winter/early spring. Testicular steroidogenic activity precedes the rise in female estrogen excretion by about 2 months, presumably to ensure maximal sperm production during the breeding season.

Using PGFM (13,14-dihydro-15-keto-prostaglandin F2α) as a non-invasive pregnancy marker for felids

“…For fecal PGFM profiles, an iterative process was used to calculate basal concentrations [23,24]. Briefly, the mean of all samples for each female was calculated and samples with concentrations greater than one standard deviation (SD) above this mean were removed.…”

The seasonal and ovarian status effects on in vitro production of domestic cat embryos between Equator and Tropic of Capricorn

“…In vitro fertilization is a powerful tool for helping manage rare populations (Pelican 2006) In vitro maturation of cat oocytes depends on different factors, such as the stage of the estrous cycle (Spindler & Wildt 1999). Additionally, seasonality ranges from being nonexistent with year-round gonadal activity as cheetah, Acinonyx jubatus (Brown et al 1996) to highly restrictive, with cyclicity occurring during an extremely narrow time window of a few weeks, as Pallas' cat, Otocolobus manul (Brown et al 2002). However, despite higher oocyte in vitro maturation (IVM) rates in cats, compared with dogs, they are lower than other species.…”

Endocrine milieu of perioestrus in the giant panda (Ailuropoda melanoleuca), as determined by non-invasive hormone measures

“…The variations in hormonal content in the faeces were not surprising because it has been known for decades that it is the temporal pattern over time, not the absolute concentrations of hormones in the blood, urine or faeces, that is most valuable as a research and management tool (for a review, see Monfort 2003). Metabolite concentrations in the faeces can also be naturally influenced by the diet , season (Bales et al 2006) and photoperiod (Brown 1997;Brown et al 2002). Because the giant pandas in the present study hailed from different facilities across different countries and cultures, and even though housing and husbandry differences appeared subtle, it was impossible to explore the specifics of external factors, such as diet and light cycle, in any depth.…”