Behavior of feral horses in response to culling and GnRH immunocontraception

AbstractWildlife management actions can alter fundamental behaviors of individuals and groups, which may directly impact their life history parameters in unforeseen ways. This is especially true for highly social animals because changes in one individual's behavior can cascade throughout its social network. When resources to support populations of social animals are limited and populations become locally overabundant, managers are faced with the daunting challenge of decreasing population size without disrupting core behavioral processes. Increasingly, managers are turning to fertility control technologies to supplement culling in efforts to suppress population growth, but little is quantitatively known about how either of these management tools affects behavior. Gonadotropin releasing hormone (GnRH) is a small neuropeptide that performs an obligatory role in mammalian reproduction and has been formulated into the immunocontraceptive GonaCon-B™. We investigated the influences of this vaccine on behavior of feral horses (Equus caballus) at Theodore Roosevelt National Park, North Dakota, USA, for a year preceding and a year following nonlethal culling and GnRH-vaccine treatment. We observed horses during the breeding season and found only minimal differences in time budget behaviors of free-ranging female feral horses treated with GnRH and those treated with saline. The differences observed were consistent with the metabolic demands of pregnancy and lactation. We observed similar social behaviors between treatment groups, reflecting limited reproductive behavior among control females due to high rates of pregnancy and suppressed reproductive behavior among treated females due to GnRH-inhibited ovarian activity. In the treatment year, band stallion age was the only supported factor influencing herding behavior (P<0.001), harem-tending behavior (P<0.001), and agonistic behavior (P=0.02). There was no difference between the mean body condition of control females (4.9 (95% CI=4.7–5.1)) and treated females (4.8 (95% CI=4.7–4.9)). Band fidelity among all females increased 25.7% in the year following vaccination and culling, despite the social perturbation associated with removal of conspecifics. Herding behavior by stallions decreased 50.7% following treatment and culling (P<0.001), while harem-tending behavior increased 195.0% (P<0.001). The amount of available forage influenced harem-tending, reproductive, and agonistic behavior in the year following culling and treatment (P<0.04). These changes reflected the expected nexus between a species with polygynous social structure and strong group fidelity and the large instantaneous change in population density and demography coincident with culling. Behavioral responses to such perturbation may be synergistic in reducing grazing pressure by decreasing energetically expensive competitive behaviors, but further investigation is needed to explicitly test this hypothesis

Binding characteristics of the ovine membrane progesterone receptor alpha and expression of the receptor during the estrous cycle

BACKGROUND: Classically, progesterone has been thought to act only through the well-known genomic pathway involving hormone binding to nuclear receptors and subsequent modulation of gene expression. However, there is increasing evidence for rapid, non-genomic effects of progesterone in a variety of mammalian tissues and it is possible that a membrane PR (mPR) is causing these events. We recently isolated and characterized an ovine mPR referred to as mPR-alpha, distinct from the nuclear PR. Based on predicted structural analysis, the ovine mPR-alpha possesses seven transmembrane domains typical of G protein-coupled receptors. Despite the homology to other reported mPRs, information pertaining to the steroid binding characteristics of the ovine mPR-alpha was lacking. Additionally, the ovine mPR-alpha transcript has been identified in the hypothalamus, pituitary, uterus, ovary and corpus luteum, yet changes in expression of the ovine mPR-alpha in these tissues were not known. Consequently, the purpose of this work was to determine the steroid binding characteristics of the ovine mPR-alpha and to investigate possible changes in expression of the ovine mPR-alpha in reproductive tissues throughout the estrous cycle. METHODS: Binding studies were performed using crude membrane fractions from CHO cells expressing the mPR-alpha. Using quantitative Real-time PCR we determined the expression pattern of mRNA for the ovine mPR-alpha during the ovine estrous cycle in tissues known to express the mPR-alpha. Jugular blood samples were also collected and analyzed for serum concentrations of P4 to ensure ewes were at the appropriate stage of their cycle. RESULTS: Only progesterone, 20alpha-hydroxyprogesterone and 17alpha-hydroxyprogesterone were able to displace binding of 3H-P4 (P < 0.001) to membrane fractions from CHO cells expressing ovine mPR-alpha. The average B-max and Kd values for three separate experiments were 624 +/- 119 fmol/micro gram protein and 122 +/- 50 nM, respectively. Significant changes in expression of mRNA for the mPR-alpha during the estrous cycle were noted in the corpus luteum and uterus. CONCLUSION: The mPR-alpha specifically binds progestins and its expression was correlated to progesterone secretion during the ovine estrous cycle. Results from the present studies suggest that mPR-alpha may have an important physiological role during the ovine estrous cycle

Membrane-initiated actions of estradiol (E2) in the regulation of LH secretion in ovariectomized (OVX) ewes

Abstract Background We demonstrated that E2 conjugated to BSA (E2BSA) induces a rapid membrane-initiated inhibition of LH secretion followed hours later by a slight increase in LH secretion. Whether these actions of E2BSA are restricted to the pituitary gland and whether the membrane-initiated pathway of E2BSA contributes to the up-regulation of the number of GnRH receptors during the positive feedback effect of E2 were evaluated here. We have shown that the suppression of LH secretion induced by E2 and E2BSA is the result of a decreased responsiveness of the pituitary gland to GnRH. In this study we further tested the ability of E2BSA to decrease the responsiveness of the pituitary gland to GnRH under the paradigm of the preovulatory surge of LH induced by E2. Methods For the first experiment GnRH and LH secretions were determined in samples of pituitary portal and jugular blood, respectively, in ewes treated with 12 mg E2BSA. In the second experiment, the number of GnRH receptors was quantified in ewes 12 h after administration of 25 micrograms E2 (the expected time for the increase in the number of GnRH receptors and the positive feedback effect of E2 in LH secretion) or 12 mg E2BSA. In the third experiment, the preovulatory-like surge of LH was characterized in ewes injected with 25 micrograms E2 alone or followed 8 h later (before the beginning of the LH surge) with 60 mg E2BSA. Results a) the decrease in LH secretion induced by E2BSA was not accompanied by changes in the pulsatile pattern of GnRH, b) E2BSA increased the number of GnRH receptors, and c) the presence of E2BSA in E2-treated ewes delayed the onset, reduced the length, and decreased the amount of LH released during the preovulatory surge of LH. Conclusions a) the rapid suppression of LH secretion induced by E2BSA is mediated only via a direct action on the pituitary gland, b) E2 acting via a membrane-initiated pathway contributes to increase the number of GnRH receptors and, c) administration of E2BSA near the beginning of the pre-ovulatory surge of LH delays and reduces the magnitude of the surge.http://deepblue.lib.umich.edu/bitstream/2027.42/112939/1/12958_2009_Article_665.pd

Reimmunization increases contraceptive effectiveness of gonadotropin-releasing hormone vaccine (GonaCon-Equine) in freeranging horses (\u3ci\u3eEquus caballus\u3c/i\u3e): Limitations and side effects

Wildlife and humans are increasingly competing for resources worldwide, and a diverse, innovative, and effective set of management tools is needed. Controlling abundance of wildlife species that are simultaneously protected, abundant, competitive for resources, and in conflict with some stakeholders but beloved by others, is a daunting challenge. Free-ranging horses (Equus caballus) present such a conundrum and managers struggle for effective tools for regulating their abundance. Controlling reproduction of female horses presents a potential alternative. During 2009±2017, we determined the long-term effectiveness of GnRH vaccine (GonaCon-Equine) both as a single immunization and subsequent reimmunization on reproduction and side effects in free-ranging horses. At a scheduled management roundup in 2009, we randomly assigned 57 adult mares to either a GonaCon-Equine treatment group (n = 29) or a saline control group (n = 28). In a second roundup in 2013, we administered a booster vaccination to these same mares. We used annual ground observations to estimate foaling proportions, social behaviors, body condition, and injection site reactions. We found this vaccine to be safe for pregnant females and neonates, with no overt deleterious behavioral side effects during the breeding season. The proportion of treated mares that foaled following a single vaccination was lower than that for control mares for the second (P = 0.03) and third (P = 0.08) post-treatment foaling seasons but was similar (P = 0.67) to untreated mares for the fourth season, demonstrating reversibility of the primary vaccine treatment. After two vaccinations, however, the proportion of females giving birth was lower (

Kisspeptin in prepuberal heifers: 2. Response of LH, FSH and GH to different doses of kisspeptin-10 and its association with circulating IGF-I and leptin

En becerras prepúberes, la kisspeptina-10 (KISS-10) estimula la liberación de hormona luteinizante (LH) y hormona foliculoestimulante (FSH), pero su acción en la hormona del crecimiento (GH) es inconsistente. La hipótesis fue que en becerras prepúberes la magnitud de liberación de LH, FSH y GH en respuesta a KISS-10 es determinada por la dosis y las concentraciones endógenas de IGF-I y leptina. Se usaron 20 becerras prepúberes (100-232 kg de peso y 7-11 meses de edad), mismas que recibieron un bolo i.v. de 5 o 50 µg de  KISS-10/kg de peso. Ambas dosis de KISS-10 indujeron un incremento de LH y FSH, más no de GH. La dosis de 50 µg de KISS-10 indujo un área bajo la curva de LH y una duración del incremento de FSH mayores (P0.05). De la misma forma, las concentraciones de leptina no determinaron (P>0.05) la magnitud del incremento de LH y FSH ni las concentraciones de GH pos tratamiento. En conclusión, la GH no respondió a ninguna dosis, pero la FSH y la LH fueron sensibles al aumento de dosis de KISS-10. Además, la magnitud de respuesta de LH a KISS-10 fue determinada por las concentraciones endógenas de IGF-I, pero no de leptina.In prepubertal heifers, kisspeptin-10 (KISS-10) stimulates the release of the luteinizing hormone (LH) and the follicle-stimulating hormone (FSH) but the growth hormone (GH) response is inconsistent. The hypothesis of this study was that in prepubertal heifers, the release of LH, FSH and GH in response to KISS-10 is determined by dose and by endogenous levels of IGF-I and leptin. Twenty heifer calves (100-232 kg of body weight and 7-11 mo of age) received an i.v. injection of 5 or 50 µg of KISS-10/kg of body weight (low and high dose, respectively). The high dose of KISS-10 induced a greater (P0.05). The magnitude of FSH response as well as GH serum concentrations after KISS-10 were not altered by IGF-I levels (P>0.05). Similarly, leptin concentrations were not associated (P>0.05) with the magnitude of LH and FSH response or GH concentrations after KISS-10. In conclusion, GH did not respond to any dose of KISS-10 but FSH and LH were sensitive to an increment in the KISS-10 dose. Additionally, the magnitude of response of LH to KISS-10 was determined by endogenous levels of IGF-I but it was not associated with levels of leptin

Kisspeptina en becerras prepúberes: I. Influencia de la edad en la respuesta de LH, FSH y GH a kisspeptina-10 y su asociación con IGF-I, leptina y estradiol

To evaluate effects of age on the response of LH, FSH and GH to kisspeptin-10 (KISS) in prepubertal heifers and its association with circulating levels of IGF-I, estradiol (E2) and leptin, 21 heifer calves that were 4, 7 or 11 mo old, received an iv injection of KISS (5 μg/kg). LH, FSH and GH were quantified in blood serum taken every 15 min (4 h pre- and 4 h post-KISS-10). In three pre- and six post-KISS samples, IGF-I, leptin and E2 were determined. All heifers responded to KISS with an LH increment but the response magnitude differed among groups since maximum value was higher (P<0.05) in 11 mo (11.6+1.3 ng/ml) than in 7 mo (7.2±1.3 ng/ml) and 4 mo (6.1±1.3 ng/ml) old calves. Duration of response differed (P<0.05) among ages (11 mo=132.9+20 mina; 7 mo=92±20 mina,b; 4 mo=64.3±20 minb). For FSH, all and 11 mo calves responded to KISS but only 71.4 % of 4 mo did. In GH, 71.4 % of 4 mo and 85.7 % of 7 mo calves responded to KISS whereas 100 % of 11 mo animals responded. FSH and GH did not differ among age groups. The 11 mo heifers had the highest IGF-I and E2 but the lowest leptin levels. In conclusion, KISS evokes LH increments in all calves 4 to 11 mo old, but the response increases with age in association with high circulating IGF-I and E2 and low leptin. The response of FSH and GH to KISS is not influenced by age or variations in circulating IGF-I, E2 or leptin. El objetivo fue evaluar la respuesta de LH, FSH y GH a kisspeptina-10 (KISS) en becerras prepúberes de distintas edades, y su asociación con IGF-I, E2 y leptina circulantes. A 21 becerras de 4, 7 y 11 meses de edad se les aplicó una inyección i.v. de 5 µg de KISS/kg de peso. En suero obtenido de la yugular (cada 15 min, 4 h pre hasta 4 h post-KISS) se cuantificó LH, FSH y GH. En nueve muestras (tres pre y seis post-KISS) se determinó IGF-I, leptina y estradiol (E2). En todas las becerras aumentó la LH post-KISS, con un valor máximo (6.1±1.3a, 7.2±1.3a, 11.6+1.3b ng/ml) y duración de respuesta (64.3±20a, 92±20b, 132.9+20c min) que aumentó (P<0.05) con la edad. Para FSH, 71.4, 100 y 100 % de las becerras de 4, 7 y 11 meses respondieron a KISS-10; situación que para GH fue 71.4, 85.7 y 100 %, respectivamente. La magnitud de la respuesta de FSH y GH a KISS fue similar entre edades. Las becerras de 11 meses tuvieron las máximas concentraciones de IGF-I y E2 y las menores de leptina. Se concluye que KISS-10 evoca un aumento de LH en becerras de 4 a 11 meses, cuya magnitud de respuesta se asocia con la edad, con el incremento en sangre periférica de IGF-I y E2 y con la disminución de leptina sérica; en contraste, la respuesta de GH y FSH a KISS-10 no es afectada por la edad ni por las variaciones en IGF-I, E2 y leptina

Discordant identification of pediatric severe sepsis by research and clinical definitions in the SPROUT international point prevalence study

Introduction: Consensus criteria for pediatric severe sepsis have standardized enrollment for research studies. However, the extent to which critically ill children identified by consensus criteria reflect physician diagnosis of severe sepsis, which underlies external validity for pediatric sepsis research, is not known. We sought to determine the agreement between physician diagnosis and consensus criteria to identify pediatric patients with severe sepsis across a network of international pediatric intensive care units (PICUs). Methods: We conducted a point prevalence study involving 128 PICUs in 26 countries across 6 continents. Over the course of 5 study days, 6925 PICU patients &lt;18 years of age were screened, and 706 with severe sepsis defined either by physician diagnosis or on the basis of 2005 International Pediatric Sepsis Consensus Conference consensus criteria were enrolled. The primary endpoint was agreement of pediatric severe sepsis between physician diagnosis and consensus criteria as measured using Cohen's ?. Secondary endpoints included characteristics and clinical outcomes for patients identified using physician diagnosis versus consensus criteria. Results: Of the 706 patients, 301 (42.6 %) met both definitions. The inter-rater agreement (? ± SE) between physician diagnosis and consensus criteria was 0.57 ± 0.02. Of the 438 patients with a physician's diagnosis of severe sepsis, only 69 % (301 of 438) would have been eligible to participate in a clinical trial of pediatric severe sepsis that enrolled patients based on consensus criteria. Patients with physician-diagnosed severe sepsis who did not meet consensus criteria were younger and had lower severity of illness and lower PICU mortality than those meeting consensus criteria or both definitions. After controlling for age, severity of illness, number of comorbid conditions, and treatment in developed versus resource-limited regions, patients identified with severe sepsis by physician diagnosis alone or by consensus criteria alone did not have PICU mortality significantly different from that of patients identified by both physician diagnosis and consensus criteria. Conclusions: Physician diagnosis of pediatric severe sepsis achieved only moderate agreement with consensus criteria, with physicians diagnosing severe sepsis more broadly. Consequently, the results of a research study based on consensus criteria may have limited generalizability to nearly one-third of PICU patients diagnosed with severe sepsis

Effects of GonaCon Immunocontraceptive Vaccine in Free-Ranging Female Rocky Mountain elk (\u3ci\u3eCervus elaphus nelsoni\u3c/i\u3e)

Duration of efficacy and prevalence of side-effects associated with GonaCon Immunocontraceptive Vaccine (GonaCon) in free-ranging female elk (Cervus elaphus) are unknown. In January 2008, we captured 120 mature female elk in Rocky Mountain National Park (CO, USA), determined pregnancy status, and randomly assigned them to treated (n=60; 1.5 mL of GonaCon) or control (n=60; 1.5 mL of saline) groups. During the following 3 winters we recaptured, collected blood for antibody concentrations, and euthanized 10–20 elk in each group. At necropsy, we determined pregnancy and collected tissues from organs associated with the hypothalamic–pituitary–gonadal axis. We relocated injection sites, collected muscle tissue, and performed bacterial culture when inflammation was present. Proportion of pregnant elk among control females ranged from 0.75 to 0.90. Proportion pregnant after treatment with GonaCon was 0.00 (95% CI=0.0–0.22) in year 1, 0.31 (CI=0.09–0.61) in year 2, and 0.65 (CI=0.41–0.85) in year 3. Antibody concentrations were higher in non-pregnant than pregnant treated females. We found no antemortem evidence of lameness or swelling at the injection site; however, at necropsy all treated females had pyogranulomatous inflammation at the injection site. We observed no consistent changes within the hypothalamic–pituitary–gonadal axis. We conclude that GonaCon is effective at reducing pregnancy for 1–2 years post-vaccination and is strongly associated with sterile inflammation at the site of injection. Similar to other species, the vaccine is less effective in elk under free-ranging conditions than those in a captive environment