An Investigation of Ovarian and Adrenal Hormone Activity in Post-Ovulatory Cheetahs (Acinonyx jubatus)

Abstract

Cheetahs have been the subject of reproductive study for over 35 years, yet steroid hormone activity remains poorly described after ovulation. Our objective was to examine and compare fecal progestagen (fPM), estrogen (fEM), and glucocorticoid (fGM) metabolite concentrations post-ovulation in pregnant and non-pregnant animals to better understand female physiology (1) during successful pregnancy, (2) surrounding frequent non-pregnant luteal phases, and (3) after artificial insemination (AI) to improve the low success rate. Secondarily, the authors also validated a urinary progestagen metabolite assay, allowing pregnancy detection with minimal sample collection. Fecal samples were collected from 12 females for ≥2 weeks prior to breeding/hormone injection (the PRE period) through 92 days post-breeding/injection. Samples were assessed for hormone concentrations using established enzyme immunoassays. Urine samples were collected for 13 weeks from 6 females after natural breeding or AI. There were no differences among groups in fGM, but in pregnant females, concentrations were higher (p < 0.01) in the last trimester than any other time. For pregnant females that gave birth to singletons, fGM was higher (p = 0.0205), but fEM tended to be lower (p = 0.0626) than those with multi-cub litters. Our results provide insight into the physiological events surrounding natural and artificially stimulated luteal activity in the cheetah.

Changes in Fecal Glucocorticoid Metabolites in Captive Coyotes (Canis latrans): Influence of Gender, Time, and Reproductive Status

“…For example, female fisher ( Pekania pennanti ; [ 21 ], which can breed once a year, and domestic cats [ 30 ], which can breed several times a year, did not exhibit any relationship between cortisol levels measured in hair and litter size. In contrast, captive cheetah females with a single cub had higher fGCMs than those with multiple cubs [ 9 ], suggesting that higher metabolic costs and cortisol levels before or during breeding reduced the amount of energy available to developing oocytes, and thus, fewer embryos were released. Wolves and bears ( Ursus spp.)…”

“…Glucocorticoids (GC) and their glucocorticoid metabolites (GCMs), including cortisol and corticosterone, are hormones involved in regulating energy [1] and assist most Animals 2023, 13, 3596 2 of 15 mammals [2], including carnivores [3][4][5][6][7], to overcome stressful or metabolic changing situations [2,8,9]. Stress is a cascade of neurological, hormonal, and immunological responses to changes in the environment [10] and includes daily responses to metabolic situations such as digestion and sleeping, as well as long-term challenges such as reproduction [9].…”

“…Glucocorticoids (GC) and their glucocorticoid metabolites (GCMs), including cortisol and corticosterone, are hormones involved in regulating energy [1] and assist most Animals 2023, 13, 3596 2 of 15 mammals [2], including carnivores [3][4][5][6][7], to overcome stressful or metabolic changing situations [2,8,9]. Stress is a cascade of neurological, hormonal, and immunological responses to changes in the environment [10] and includes daily responses to metabolic situations such as digestion and sleeping, as well as long-term challenges such as reproduction [9]. Multiple factors (e.g., age, breeding status, environmental conditions, food quality and quantity, social status, and species) influence GCM levels [1], and there is no general GCM profile for how wild animals respond to stress [11].…”