Ovarian and immunological responses to alternating exogenous gonadotropin regimens in the ocelot (Leopardus pardalis) and tigrina (Leopardus tigrinus)
Abstract 10.1002/zoo.20049.abs Exogenous gonadotropins frequently are used to stimulate ovarian follicular growth and ovulation in mammalian species, including felids. However, repeated exogenous gonadotropin treatment can result in decreased ovarian responsiveness due to antibody formation. In this study, our objectives were to assess the effectiveness of alternating gonadotropin regimens on ovarian responses in ocelots and tigrinas, […]
Estrogen and LH dynamics during the follicular phase of the estrous cycle in the Asian elephant
Abstract 10.1002/zoo.10098.abs Pituitary and corpus luteum hormone patterns throughout the elephant estrous cycle have been well characterized. By contrast, analysis of follicular maturation by measurement of circulating estrogens has been uninformative. This study tested the ability of a urinary estradiol-3-glucuronide radioimmunoassay to noninvasively assess follicular development during the nonluteal phase of the elephant estrous cycle, […]
Reproductive endocrine patterns in captive female and male red wolves (Canis rufus) assessed by fecal and serum hormone analysis
Abstract Reproductive steroid profiles in female (n=13) and male (n=5) red wolves (Canis rufus) were characterized in fecal samples collected during the breeding season (December—May) and over a 1 year period, respectively. Blood samples from females (n=12) also were collected during the periovulatory period for luteinizing hormone (LH) and steroid analysis. High performance liquid chromatography […]
Endocrine and ultrasound evaluation of a non-cycling African elephant: Identification of an ovarian follicular cyst
The reproductive rate of captive African elephants is low because of logistical difficulties associated with transporting animals for breeding, the danger of maintaining bulls and medical or physiological problems. There also is growing evidence that a significant number of mature female elephants are not experiencing normal estrous cycles. The case described in this report involves […]
Analysis of urinary immunoreactive steroid metabolites and gonadotropins for characterization of the estrous cycle, breeding period, and seasonal estrous activity of captive killer whales (Orcinus orca)
Abstract 10.1002/zoo.1430120204.abs To increase the basic understanding of killer whale (Orcinus orca) reproductive physiology necessary for the development of artificial breeding programs, we utilized radioimmunoassays (RIA) to detect urinary immunoreactive steroid metabolites (pregnanediol-3α-glucuronide [PdG] and estrone-conjugates [EC]) and gonadotropins (luteinizing hormone [LH] and follicle-stimulating hormone [FSH]) in urine samples from six female killer whales. Urine […]
Stress-induced increase of testosterone: Contributions of social status and sympathetic reactivity
The vast number of studies in both human and animals confirm the inhibiting role of different stressors in the hormonal function of the testicles, decreasing the testosterone (T) level in the blood. However, there also are data suggesting that stress does not invariably inhibit the activity of the testicles. Moreover, the T level in blood […]
Acute and chronic stress-like levels of cortisol inhibit the oestradiol stimulus to induce sexual receptivity but have no effect on sexual attractivity or proceptivity in female sheep
Stress-like levels of cortisol inhibit sexual receptivity in ewes but the mechanism of this action is not understood. One possibility is that cortisol interferes with the actions of oestradiol to induce sexual receptivity. We tested this hypothesis in 2 experiments with ovariectomised ewes that were artificially induced into oestrus by 12 days of i.m. injections of […]
Extension of reproductive suppression by pheromonal cues in subordinate female marmoset monkeys, Callithrix jacchus
Pheromonal signals from the dominant female marmoset monkey were implicated in maintaining the suppression of LH secretion and ovulation in socially subordinate females. When subordinate, and reproductively suppressed, female marmoset monkeys were removed from their group without scent contact with their dominant females, subordinate females in control group 1 (N = 8) and control group […]
INVITED REVIEW: The usefulness of measuring glucocorticoids for assessing animal welfare
Glucocorticoids (corticosterone in birds and rodents and cortisol in all other mammals) are glucoregulatory hormones that are synthesized in response to a range of stimuli including stress and are regularly measured in the assessment of animal welfare. Glucocorticoids have many normal or non-stress-related functions, and glucocorticoid synthesis can increase in response to pleasure, excitement, and […]