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Theriogenology.
Publisher:
Geron-X.. [New York, N.Y.?] : Elsevier
Frequency: Sixteen no. a year
Country: United States
Language: English
Start Year:1974 -
ISSN:
0093-691X (Print)
1879-3231 (Electronic)
0093-691X (Linking)
1879-3231 (Electronic)
0093-691X (Linking)
Impact Factor
2.8
2022
| NLM ID: | 0421510 |
| (OCoLC): | 02504829 |
| (DNLM): | T08780000(s) |
| Coden: | THGNBO |
| Classification: | W1 TH677K |
Concentrations of altrenogest in plasma of mares and foals and in allantoic and amniotic fluid at parturition. Treatment with the progestin altrenogest is widely used in pregnant mares. The fact that foals born from healthy mares treated with altrenogest until term suffered from neonatal problems raises the question of direct effects of altrenogest on vital functions in the neonate. We have therefore investigated altrenogest concentrations in maternal and neonatal blood plasma and in fetal fluids. Pregnant mares were treated with altrenogest orally once daily (0,088 mg/kg bodyweight, n = 7) or left untreated (n = 8) from 280 d of gestation until foaling. Altrenogest concentration was determined in plas...
Treatment efficacy of trimethoprim sulfamethoxazole, pentoxifylline and altrenogest in experimentally induced equine placentitis. The objective was to determine if long-term treatment with trimethoprim sulfamethoxazole (antimicrobial), pentoxifylline (anti-inflammatory/anti-cytokine) and altrenogest (synthetic progestin), would improve pregnancy outcome in mares with experimentally induced placentitis. Seventeen normal, pregnant pony mares were enrolled in the study at 280-295 d of pregnancy. Placentitis was induced in all mares by intra-cervical inoculation of Streptococcus equi subsp. zooepidemicus (10(7) CFU). Five mares served as infected, untreated control animals (Group UNTREAT). Twelve mares (Group TREAT) were inf...
Heat shock protein 70 gene expression in equine blastocysts after exposure of oocytes to high temperatures in vitro or in vivo after exercise of donor mares. Heat above homeothermy can be detrimental to embryonic development, and cells may produce heat shock proteins to try to mitigate these effects. The authors examined the developmental competence of equine oocytes after a single heat exposure (42 degrees C, 2 or 4 h) during early or late stages of in vitro maturation. Rates of nuclear maturation, cleavage after intracytoplasmic sperm injection, and advanced embryonic development (morula or blastocyst) were compared to those for unexposed controls. Concentrations of heat shock protein 70 (HSPA1A) mRNA were determined by real-time RT-PCR in result...
Cellular localization of androgen synthesis in equine granulosa-theca cell tumors: immunohistochemical expression of 17alpha-hydroxylase/17,20-lyase cytochrome P450. Elevated blood testosterone concentrations, often accompanied by male-typical behaviors, is a common signalment of mares with granulosa-theca cell tumors (GCTCs), but no definitive information exists regarding the cellular differentiation of tumors associated with androgen secretion. This study was conducted to localize and thereby define the cellular expression of 17alpha-hydroxylase/17,20-lyase cytochrome P450 (P450c17), the enzyme most directly responsible for androgen synthesis, in 30 GTCTs and control tissues (gonads and adrenal glands) using immuno-histochemistry (IHC). Immuno-reactivity...
Short-term feed restriction decreases the systemic and intrafollicular concentrations of leptin and increases the vascularity of the preovulatory follicle in mares. The objective of this study was to evaluate the effect of short-term feed restriction on characteristics of the preovulatory follicle and on concentrations of systemic hormones (leptin, follicle-stimulating hormone [FSH], luteinizing hormone [LH]) and follicular fluid hormones and growth factors (leptin, estradiol, inhibin-A, activin-A, free insulin-like growth factor-1 [IGF1], insulin-like growth factor binding protein 2 [IGFBP2], vascular endothelial growth factor [VEGF]). Mares were submitted to a short-term (48 h) feed restriction when the expected ovulatory follicle was > or =27 mm (Ho...
Factors affecting the incidence of postpartum oestrus, ovarian activity and reproductive performance in Thoroughbred mares bred at foal heat under Indian subtropical conditions. Decreased reproductive performance due to summer stress is a well known phenomenon in farm livestock. Whether this occurs in the mare and specifically how this might affect postpartum reproductive activity and performance, especially at Foal Heat (FH), is unknown. This study, therefore, aims to investigate this and the factors that might affect postpartum reproductive activity. Reproductive records of 228 Thoroughbred mares (694 mare years) bred in subtropical north-western India were retrospectively analysed. Overt oestrous activity occurred within 21 d postpartum in 92.94% (645/694) of mares...
Influence of different centrifugation protocols on equine semen preservation. Three experiments were conducted to evaluate the impact of centrifugation on cooled and frozen preservation of equine semen. A standard centrifugation protocol (600 x g for 10 min=CP1) was compared to four protocols with increasing g-force and decreased time period (600 x g, 1200 x g, 1800 x g and 2400 x g for 5 min for CP2, 3, 4, and 5, respectively) and to an uncentrifuged negative control. In experiment 1, the influence of the different CPs on sperm loss was evaluated by calculating the total number of sperm cells in 90% of the supernatant. Moreover, the effect on semen quality following ce...
Recovery of mare oocytes on a fixed biweekly schedule, and resulting blastocyst formation after intracytoplasmic sperm injection. Oocytes may be collected from live mares from either the stimulated preovulatory follicle or from all visible immature follicles. We evaluated the yield of mature oocytes, and of blastocysts after intracytoplasmic sperm injection (ICSI), for both follicle types. In Experiment 1, mares were assigned to Progesterone (1.2g biorelease progesterone weekly) or Control treatments. Transvaginal aspiration of all follicles was performed every 14 d. Overall, 596 follicles were aspirated, with a 54% oocyte recovery rate. There was no difference between treatments in number of follicles punctured (9.0 to ...
Lectin-binding sites on ejaculated stallion sperm during breeding and non-breeding periods. Stallion sperm from semen collected in Southern Italy during the breeding (June-July) and non-breeding (December-January) periods were analyzed by means of twelve lectins to evaluate the glycoconjugate pattern and to verify whether there are any seasonal differences in the glycosylation pattern of the sperm glycocalyx. The acrosomal cap showed reactivity for Maackia amurensis (MAL II), Sambucus nigra (SNA), Arachis hypogaea (PNA), Glycine max (SBA), Helix pomatia (HPA), Canavalia ensiformis (Con A) Triticum vulgaris (WGA), and Griffonia simplicifolia isolectin II (GSA II) in breeding and non-b...
Determination of heart rate and heart rate variability in the equine fetus by fetomaternal electrocardiography. Heart rate is an important parameter of fetal well-being. We have analyzed fetal heart rate (HR) and heart rate variability (HRV) by fetomaternal electrocardiography (ECG) in the horse (Equus caballus) from midpregnancy to foaling. It was the aim of the study to detect changes in the regulation of fetal cardiac activity over time and to establish normal values in undisturbed pregnancies. A total of 22 mares were available for the study. Fetomaternal electrocardiography was a reliable technique to detect cardiac signals in fetuses between Day 173 of gestation and foaling. Fetal HR decreased fro...
Seasonal functional relevance of sperm characteristics in equine spermatozoa. A group of stallions with different reproductive indexes were used to study seasonal variations in sperm quality (Equus caballus). Semen samples were collected from late September to July and analyzed according to four seasonal periods: late September-December, January-March, late March-May, and June-July. Parameters monitored included sperm concentration, sperm motility, sperm morphology, sperm viability, acrosomal status, plasma membrane stability, and sperm mitochondrial membrane potential. Overall, seminal parameters monitored are affected mostly by time period, followed by animal and last...
Equine embryos and embryonic stem cells: defining reliable markers of pluripotency. Cartilage and tendon injuries are a significant source of animal wastage and financial loss within the horse-racing industry. Moreover, both cartilage and tendon have limited intrinsic capacity for self-repair, and the functionally inferior tissue produced within a lesion may reduce performance and increase the risk of reinjury. Stem cells offer tremendous potential for accelerating and improving tissue healing, and adult mesenchymal stem cells (MSCs) are already used to treat cartilage and tendon injuries in horses. However, MSCs are scarce in the bone marrow isolates used, have limited poten...
Oxytocin, vasopressin, prostaglandin F(2alpha), luteinizing hormone, testosterone, estrone sulfate, and cortisol plasma concentrations after sexual stimulation in stallions. This experiment was designed to determine the effects of sexual stimulation on plasma concentrations of oxytocin (OT), vasopressin (VP), 15-ketodihydro-PGF(2alpha) (PG-metabolite), luteinizing hormone (LH), testosterone (T), estrone sulfate (ES), and cortisol (C) in stallions. Semen samples were collected from 14 light horse stallions (Equus caballus) of proven fertility using a Missouri model artificial vagina. Blood samples were collected at 15, 12, 9, 6, and 3 min before estrous mare exposure, at erection, at ejaculation, and at 3, 6, and 9 min after ejaculation. Afterwards, blood sampling ...
Venous blood lactate evaluation in equine neonatal intensive care. The use of blood lactate concentration as an indicator of prognosis and disease severity has become a common practice in equine medicine, especially with the validation of handheld analyzers. However, few authors described lactate concentration in critically ill foals, and there are no published studies about the use of handheld analyzers in neonatal foals. In this study, for the first time in the equine neonate, we validated the Lactate Scout analyzer, both in healthy and in critically ill foals. The study also describes the normal range for blood lactate in 26 healthy neonatal foals during t...
Effects of in vitro exposure to natural levels of zearalenone and its derivatives on chromatin structure stability in equine spermatozoa. The purpose of this study was to assess the natural exposure of male horses (Equus caballus) to the mycotoxin zearalenone (ZEA) by using the ELISA test and to evaluate the effects of in vitro exposure of sperm cells to mycotoxin-containing urine extracts on sperm chromatin structure stability. Because of their occurrence in urine samples, ZEA and its derivatives were tested by sperm chromatin structure assay (SCSA) at natural levels detected by ELISA. Thirty-eight urine extracts of Italian (n = 11) and northeastern European (n = 27) horses were tested on frozen-thawed spermatozoa to evaluate t...
Immediate and delayed (after cooling) effects of centrifugation on equine sperm. The objectives of this study were to determine the effects of centrifugation on equine sperm total and progressive motility, viability, and acrosomal integrity. We hypothesized that although high centrifugation forces would be detrimental to equine Equus caballus sperm, recovery rates would increase. Ejaculates from six stallions were collected, extended to a concentration of 25x10(6) cells/mL, and subjected for 10min to (1) no centrifugation (NC) or (2) centrifugation at 400xg, (3) 900xg, or (4) 4500xg. Before and after centrifugation (Day 0), and after 24h of cooling (Day 1), sperm motility ...
Effect of oxytocin and flunixin meglumine on uterine response to insemination in mares. The most probable reason for persistent postbreeding endometritis in mares is weak myometrial contractility. The influence of oxytocin (OT; an ecbolic agent) and flunixin meglumine (FLU; a prostaglandin inhibitor serving as a model for mares with decreased uterine contractility) on uterine response to artificial insemination (AI) was studied in mares with no history of reproductive failure. The mares were treated intravenously with 10 mL saline (Group C, n=10) or 0.01 IU/kg OT (Group OT, n=10) 2, 4, 8, and 25 h after AI. Group FLU (n=11) was treated with 1.1mg/kg FLU 2h after AI and with salin...
The effect of hormone treatments (hCG and cloprostenol) and season on the incidence of hemorrhagic anovulatory follicles in the mare: a field study. The association between use of hormone treatments to induce estrus and ovulation and the incidence of hemorrhagic anovulatory follicles (HAFs) was studied in a mixed population of mares (Equus caballus) during two breeding seasons in a commercial breeding clinic. Mares treated with cloprostenol (CLO) were more likely to develop HAFs than were mares with spontaneous cycles (P0.05) from that of mares with ovulatory cycles (10.5+/-1.5 yr).
Sexual behavior and ejaculate characteristics in Pêga donkeys (Equus asinus) mounting estrous horse mares (Equus caballus). The objectives were to (i) characterize sexual behavior of donkey stallions (jacks; Equus asinus) during on-farm semen collection using estrous horse mares (mares; Equus caballus); (ii) compare behavior of young (less experienced) versus older (more experienced) jacks; (iii) determine whether semen suitable for artificial insemination (AI) could be collected using mares; and (iv) determine the suitability of using mares in field collection of semen from jacks. Six Pêga jacks (3.5 to 16 yr old), previously conditioned to breed mares, were used. Mount mares were confirmed in estrus by a teaser ...
Concentrations of 15-ketodihydro-PGF2alpha, cortisol, and progesterone in the plasma of healthy and pathologic newborn foals. Information regarding the plasma hormone profiles of prostaglandins (PGs), cortisol (C), and progesterone (P4) during pathologic processes in newborn foals is scarce. The aim of this study was to determine the plasma concentrations of these hormones in diseased foals (n=40) and healthy at-term foals (n=24) (Equus caballus) during the first 2 weeks of life. Blood samples were collected daily, before any treatment with nonsteroidal drugs in diseased foals, and plasma was analyzed by radioimmunoassay. 15-Ketodihydro-PGF(2alpha) (PGM) was consistently higher in diseased foals than in healthy foals...
Concentrations of circulating hormones normalized to pulses of a prostaglandin F2alpha metabolite during spontaneous luteolysis in mares. The temporal relationships between a pulse of 13,14-dihydro-15-keto-PGF(2alpha) (PGFM) and the concentrations of circulating hormones during the luteolytic period were studied for 11 pulses in 11 mares (Equus caballus) using samples collected hourly. Mean PGFM pulses encompassed 4h before to 4h after the peak, and hormone data were normalized to the PGFM peak (Hour 0). Concentration of progesterone decreased (P < 0.05) between Hours -4 and -3 and continued to decrease linearly throughout the PGFM pulse. The concentrations of cortisol and prolactin increased (P < 0.004) during Hours -4 to...
A 40-year odyssey into the mysteries of equine luteolysis. Variation is the principal barrier to progress in unraveling the complexities of biological mechanisms. The resulting slow research progress is well illustrated in the chronology of events in elucidating the mechanism for regression of the corpus luteum (luteolysis) during the equine estrous cycle. Many of the underlying foundations of the female reproductive system in farm animals were developed during the 1930s to 1950s, despite the lack of methods for determining the concentrations of circulating hormones. In the 1960s, a uterine luteolysin was postulated on the basis of several experimenta...
Single-layer centrifugation with Androcoll-E can be scaled up to allow large volumes of stallion ejaculate to be processed easily. The objective of the current study was to optimize the volumes of Androcoll-E and sperm sample used in various sizes of centrifuge tube to scale up single-layer centrifugation (SLC) for routine use in the field. Although sperm suspensions of equivalent quality were produced using Androcoll-E in small and large tubes, the sperm yield was much lower in the latter (P<0.001). In contrast, in 200-mL tubes (XL), the yields were approximately 25% higher than those for the small tubes. An increased volume (4.5 mL) of extended ejaculate in small tubes (SLC-Inc) or 15 to 18 mL extended ejaculate on 1...
Follicle suppression of circulating follicle-stimulating hormone and luteinizing hormone before versus after emergence of the ovulatory wave in mares. The effect of the ovarian follicles on plasma concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) before versus after the expected emergence of the ovulatory follicular wave was studied on Days 0 to 18 (Day 0=ovulation) in four groups of mares (n=6/group). In addition to a control group, all follicles >/=6mm in diameter were ablated on Days 0.5, 6.5, or 12.5 in a herd of mares with reported emergence at 6mm of the future ovulatory follicle on mean Day 10.5. Concentrations of FSH were not different between the Day-0.5 or Day-6.5 ablation groups and the correspon...
Risk of equine infectious anemia virus disease transmission through in vitro embryo production using somatic cell nuclear transfer. Prevention and regulation of equine infectious anemia virus (EIAV) disease transmission solely depend on identification, isolation, and elimination of infected animals because of lack of an effective vaccine. Embryo production via the somatic cell nuclear transfer (SCNT) technology uses oocytes collected mainly from untested animals, which creates a potential risk of EIAV transmission through infected embryos. The current review examines the risk of EIAV disease transmission through SCNT embryo production and transfer. Equine infectious anemia virus is a lentivirus from the family Retroviridae...
Assessment of pregnancy in the late-gestation mare using digital infrared thermography. The objective of this study was to investigate use of digital infrared thermal imaging (DITI) to determine whether surface temperature gradient differences exist between pregnant and nonpregnant mares as a noncontact method to determine pregnancy status. On the day measurements were collected, each pregnant mare (n=10; beginning at 292.4+/-1.4 d of gestation) was paired with a nonpregnant mare (n=17). Ambient temperature, DITI measurements (left and right flank, wither temperatures [i.e., animal surface control] and background temperature), and rectal temperatures were obtained every 7 d for 5...
Physiologic and nonphysiologic effects of exogenous prostaglandin F2alpha on reproductive hormones in mares. Responses to intravenous treatment of mares with prostaglandin F2alpha (PGF) 8 d after ovulation were studied in three groups (n=4/group): control (no treatment), bolus (single treatment with 2.5 mg PGF), and infusion (0.1 mg PGF during 2 h). Infusion resulted in a 13,14-dihydro-15-keto-PGF2alpha (PGFM) concentration (559+/-44 pg/mL) that was not different from the mean concentration for the major portion of a natural PGFM pulse associated with luteolysis (569+/-45 pg/mL; n=5). Progesterone in the bolus group increased (P<0.03) between 0 (17.8+/-3.5 ng/mL) and 2 min (25.3+/-4.8 ng/mL), peak...
Lectin-binding sites in isolated equine cumulus-oocyte complexes: differential expression of glycosidic residues in complexes recovered with compact or expanded cumulus. Equine cumulus-oocyte complexes (COCs) were analyzed by means of 13 lectins to evaluate their glycoconjugate patterns and to verify differences between COCs recovered with compact (Cp) and expanded (Exp) cumulus. Cumulus cells showed a similar staining pattern in both Cp and Exp COCs with all lectins used, except for a higher reactivity with SNA and GSA II in Cp COCs and SBA in Exp COCs. The zona pellucida (ZP) showed (1) uniform staining with MAL II, RCA(120), and SBA in both Cp and Exp COCs, (2) trilaminar binding pattern with WGA as well as higher Con A reactivity in the outer region of bot...
Efficiency of superovulation and in vivo embryo production in eFSH-treated donor mares after estrus synchronization with progesterone and estradiol-17beta. Reliable methods of regulating estrus and stimulating superovulations in equine embryo transfer programs are desirable. Our objectives were to investigate the efficacy of a progesterone and estradiol-17beta (P&E) estrus synchronization regimen in mares with and without subsequent equine follicle-stimulating hormone (eFSH) treatment and to examine the effects of eFSH on folliculogenesis and embryo production. Cycling mares were treated with P&E daily for 10 d. On the final P&E treatment day, prostaglandin F(2alpha) was administered, and mares were randomly assigned to one of two tre...
Efficiency of embryonic development after intrafollicular and intraoviductal transfer of in vitro and in vivo matured horse oocytes. In vivo techniques, such as intraoviductal oocyte transfer (OT) and intrafollicular oocyte transfer (IFOT), can be considered as alternatives to bypass the lack of efficient superovulation treatments and the inadequacy of conventional in vitro fertilization techniques in the horse. We compared embryo production after transfer of in vivo recovered oocytes (1) into a recipient's oviduct or (2) into her preovulatory follicle either immediately after ovum pick-up or (3) after in vitro maturation (IVM). Recipients were inseminated with fresh semen of a stallion with a known normal fertility. Ten da...
