Estradiol Cypionate Research Articles

PSV-B-18 Effect of Puberty Induction on Embryonic Loss in Precocious Nellore Heifers

Abstract This study aimed to determine if heifers induced to puberty had damage in reproductive performance compared with heifers that reach puberty naturally. Nellore heifers (n = 210) were weaned at 8 ± 0.7 mo of age were assigned to 42 feedlot pens according to BW (184 ± 1 kg). The diet was compounded by Tifton-85 haylage (18% CP; 55% TDN) ad libitum and supplement (4g/kg of BW; 25% CP; 60% TDN). Puberty and growth were assessed weekly. At 14 mo of age, 46 heifers reached puberty naturally (precocious heifers; PH) and 164 non-pubertal heifers were submitted to puberty induction with progesterone (P4) insert for 10 days and estradiol cypionate (0.5 mg) at P4 removal (puberty induction; PI). After fourteen days, all heifers were submitted to TAI. Heifers were considered pregnant at 20 days (P20) after AI when CL had blood flow < 25% of area (Power-Doppler). Pregnancy rate was also determined at 30 (P30) and 60 (P60) days after AI by embryo detection. Early (P20 – P30) and late (P30 – P60) embryonic loss were determined. Reproductive data were analyzed by GLIMMIX, and BW was analyzed using repeated measures over time (MIXED; SAS 9.3). The PH was heavier than PI from 8 to 16 mo of age, which BW was 296 and 285 ± 3 kg at 14 mo of age, respectively. At beginning of TAI, 88% of PI heifers had a CL. Pregnancy rate was similar (P > 0.05) between treatments, in which pregnancy rate at 20, 30 or 60 days after AI was 65, 47 and 43% for PH and 61, 53 and 48% for PI, respectively. Early (26 vs 14%) and late (9 vs 9%) embryonic loss were similar (P > 0.05) in PH and PI, respectively. In summary, natural or induced pubertal heifers had similar reproductive performance.

EFECTO DE LA EXPRESIÓN DE CELOS Y LA ADICIÓN DE GnRH SOBRE LA TASA DE PREÑEZ EN VACAS HOLSTEIN EN LACTANCIA SINCRONIZADAS CON ESTRADIOL Y DISPOSITIVOS CON PROGESTERONA

The aim of this investigation was to evaluate the effect of the addition of GnRH at the beginning and end of a treatment with progesterone-releasing devices (P 4 ) and estradiol (E2) and the expression of estrus on pregnancy rates (PR) of lactating dairy cows inseminated at fixed time (FTAI). The estrus synchronization treatment consisted on the insertion of a P 4 device for 8 days and the administration of estradiol benzoate (EB) on the day of insertion and estradiol cypionate (ECP) at the time of device removal to induce ovulation. Experiment 1 was designed to determine whether the addition of GnRH at the start of the protocol improved the PR and if the division of the time of artificial insemination (AI) improved PR. The addition of GnRH on Day 0 did not improve PR (44% vs 40%) but the AI of cows showing estrus at 48 h and the administration of GnRH at 48 h and AI at 60 h of those not showing estrus resulted in higher PR than those cows that were FTAI at 48 h, regardless of estrus expression (53% vs 31%; P <0.01). Experiment 2 was designed to study follicular dynamics and assess whether the PR varies using different times of AI (48 h vs 60 h), according to the expression of estrus. The division of AI and adding GnRH at 48 h decreased the dispersion in the interval between AI and ovulation. There was an interaction (P<0.05) between the time of AI and expression of estrus. Pregnancy rates were higher in cows in estrus at 48 h that were AI at that time (47.8%) and those that were not in heat at 48 h and were AI at 60 h (53.4%) than those who were not in estrus at 48 h and were FTAI at that time (19.4%) and those that were in estrus at 48 h and were FTAI at 60 h (29.7%). In Experiment 3 PR was evaluated based on the addition or not of GnRH to cows not showing estrus at 48 h. Pregnancy rate was higher (P<0.05) in cows that were not in estrus at 48 h, that received GnRH at that time and were AI at 60 h than in cows not showing estrus and 48 h that were also AI at 60 h but without GnRH (56.0% vs 39.8%). Experiment 4 evaluated factors that may affect PR in cows treated with the protocol developed in this experiment. It was found that the heat stress of January, a body condition score <2.75 and the presence of only small follicles (<10 mm and without CL) adversely affect PR. In conclusion, the results of this series of experiments confirm the hypothesis that the inclusion of a dose of GnRH and the modification of the time of AI increase PR in lactating dairy cows treated with P 4 devices and estradiol that does not express estrus at the time of FTAI.

Effect of the addition of GnRH and a second prostaglandin F2α treatment on pregnancy per artificial insemination in lactating dairy cows submitted to an estradiol/progesterone-based timed-AI protocol

Two experiments determined whether the addition of GnRH at the beginning of an estradiol (E2)/progesterone (P4)- based synchronization protocol and/or a second dose of prostaglandin F2α (PGF2α) the day before P4 device removal improves pregnancy rate in lactating dairy cows. On Day 0, all cows received a CIDR-B device and 2 mg i.m. estradiol benzoate, and half received 200 μg i.m. gonadorelin acetate (GnRH). On Day 7, cows were further subdivided to receive PGF2α (500 μg i.m. cloprostenol) or no PGF2α treatment. On Day 8, CIDR-B were removed, and all cows received PGF2α, 1 mg estradiol cypionate and 400 IU eCG i.m., and an estrus detection aid. Experiment 1 was designed to evaluate the effect of treatments on follicular development from P4 device removal to ovulation, expression of estrus, time of ovulation and serum P4 concentrations. Cows (n = 76) were examined by ultrasonography and bled for serum P4 determinations every 12 h from the time of P4 device removal but were not inseminated. In Experiment 2, all cows (n = 1036) were inseminated based on estrus detection using tail-paint. Cows with >50% of the paint rubbed-off by 48 h after P4 device removal were inseminated at that time, whereas those not in estrus received 100 μg i.m. of GnRH and were inseminated 12 h later. In Experiment 1, the interval from P4 device removal to ovulation was 71.7 ± 1.5 h and did not differ among groups. However, cows that received 2 injections of PGF2α had a greater (P < 0.01) estrus rate and lower (P < 0.01) P4 concentrations at 48 h after P4 device removal than those that received 1 PGF2α (estrus rate: 86.8% vs 68.4% and P4 concentration: 0.12 ± 0.01 vs 0.36 ± 0.07, for 2 and 1 PGF2α, respectively). In Experiment 2, estrus rate was also influenced by the number of PGF2α treatments, regardless of whether cows received or did not receive GnRH on Day 0 (2 PGF2α: 84.7%, 438/517 vs 1 PGF2α: 65.7%, 341/519; P < 0.01). Furthermore, there was a GnRH treatment by number of PGF2α treatments interaction (P < 0.05) on P/AI that was attributed to greater (P < 0.05) P/AI in cows that received GnRH on Day 0 and 2 PGF2α than in the other three treatment groups (EB+1 PGF2α: 45.2%, 119/263; EB+2 PGF2α: 45.8%, 119/260; EB + GnRH + 1 PGF2α: 45.7%, 117/256 and EB + GnRH + 2 PGF2α: 57.2%, 147/257). It was concluded that the addition of GnRH on Day 0 and a second dose of PGF2α the day before P4 device removal improves P/AI in lactating dairy cows synchronized with an estradiol/P4-based protocol.

Systemic Estradiol Menopause Management: Return to the Old-Fashioned Way

ABSTRACT Introduction Low systemic estradiol values (&amp;lt;10 pg/ml) experienced by menopausal women are associated with multiple symptoms including hot flashes, night sweats, insomnia, mood changes/irritability, vaginal dryness, dyspareunia, dysuria, low libido, reduced arousal/orgasm, cognitive changes, weight gain and slowed metabolism. Intramuscular estradiol cypionate was first described for medical use in 1952 to treat symptoms of menopausal ovarian failure. Systemic management has evolved, including daily gels, weekly/twice weekly patches and three-month vaginal rings. These therapies have successfully reduced bothersome symptoms in &amp;gt;60% women presenting to our clinic. A subset of women cannot achieve sufficient symptom relief using these strategies due to lack of efficacy, negative side effects, (rings cannot stay in the vagina; values are too high initially and then too low; patches cause rashes or fall off; gels are too messy) or financial concerns. For these patients, we have advised returning to the “old-fashioned way” using weekly or twice weekly intramuscular (IM) injection of either estradiol valerate or cypionate. Objective This study examines experiences of this subset of women in our practice using injections of estradiol valerate or cypionate for either enhancing efficacy or financial reasons. Methods This chart review identified 22 patients (mean age 61 +/- 8 years) who had been prescribed estradiol valerate or cypionate when symptoms of genitourinary syndrome of menopause (GSM) persisted despite use of estradiol replacement gels/patches/rings, or cost was prohibitive. We have advised weekly/twice weekly IM injection of either estradiol valerate (20 mg/ml; starting dose 0.05 ml (1 mg) weekly or 0.025 ml (0.5 mg) twice weekly) or estradiol cypionate (5 mg/ml; starting dose 0.2 ml weekly (1 mg) or 0.1 ml (0.5 mg twice weekly), utlizing 1 ml syringes with 27-gauge ½ inch needle. Injections were administered into the vastus lateralis on the antero-lateral surface at mid-thigh. Alcohol was used to prepare the skin, and compression was applied for 2 minutes after the injection. We compared relief of bothersome symptoms from earlier estradiol treatments to current IM injection and monthly costs of each treatment based on GoodRx prices, assuming medications were not covered by insurance. Results All patients using injections of estradiol valerate or cypionate had their estradiol-based GSM symptoms ameliorated without complaint of inconvenience or discomfort using injections. All described injection pain as minimal. No significant side effects were noted with IM injection. The risks of IM injections of estradiol are similar to those of topical administration, requiring concomitant progesterone use in women with a uterus. Concerning finances, using a GoodRx coupon, a 5 ml bottle of estradiol valerate lasting at least a year costs approximately $50, reducing monthly cost to approximately $5/month. A 5 ml bottle of estradiol cypionate lasting at least 6 months costs approximately $150, thus about $25/month. In contrast, generic patches can cost approximately $40/month, gels $150/month and the ring $170/month. Conclusions While there remains an aversion to injections in some patients, the motivation for IM systemic estradiol replacement superseded any inconvenience. For certain individuals, the “old-fashioned way” works better both in terms of efficacy and cost, providing relief of bothersome GSM symptoms. Disclosure No

Improved fertility following a gonadotropin-releasing hormone treatment on day 2 of an estradiol and progesterone-based timed-artificial insemination protocol in lactating dairy cows

The present study evaluated the addition of gonadotropin-releasing hormone (GnRH) concomitant or 2 d after the beginning of protocols initiated with estradiol benzoate (EB). A total of 459 multiparous and 371 primiparous lactating Holstein cows were enrolled in the study. Weekly cohorts of cows were randomly assigned to 1 of 3 experimental groups that differed in the strategy to initiate the timed AI (TAI protocol. On d 0, all cows received a 1.55-g progesterone (P4) implant. Additionally, cows in the EBd0 group received 2 mg of EB i.m.; cows in the EBd0-GnRHd0 group were treated simultaneously on d 0 with 2 mg of EB plus 100 µg of gonadorelin diacetate tetrahydrate (GnRH) i.m.; and cows in the EBd0-GnRHd2 group received 2 mg of EB on d 0 and 100 µg of GnRH 48 h later (d 2). The remaining treatments in the protocol were similar among groups and included 0.53 mg (i.m.) of cloprostenol sodium (PGF2α) on d 7, followed by a second PGF2α treatment on d 9 (at the time of P4 implant withdrawal) and 1 mg of estradiol cypionate i.m. Then, TAI was performed on d 11 (48 h after P4 removal) in all experimental groups. We detected an effect of treatment on pregnancy per AI (P/AI) on d 30, in which cows from the EBd0-GnRHd2 group demonstrated greater fertility than EBd0 cows, whereas cows in the EBd0-GnRHd0 group did not differ among EBd0 and EBd0-GnRHd0 (40.5 vs. 30.4 vs. 34.4%, respectively). In summary, GnRH treatment at the beginning of an estradiol and P4-based TAI protocol increased fertility only when GnRH was given on d 2. Moreover, a more pronounced positive effect of this strategy was observed in particular classes of cows: multiparous cows, cows with greater milk production, and those receiving the first service.

Biochemical and structural basis for Moraxella catarrhalis enoyl-acyl carrier protein reductase (FabI) inhibition by triclosan and estradiol

The enoyl-acyl carrier protein reductase (ENR) is an established drug target and catalyzes the last reduction step of the fatty acid elongation cycle. Here, we report the crystal structures of FabI from Moraxella catarrhalis (McFabI) in the apo form, binary complex with NAD+ and ternary complex with NAD + -triclosan (TCL) determined at 2.36, 2.12 and 2.22 Å resolutions, respectively. The comparative study of these three structures revealed three different conformational states for the substrate-binding loop (SBL), including an unstructured intermediate, a structured intermediate and a closed conformation in the apo, binary and ternary complex forms, respectively; indicating the flexibility of SBL during the ligand binding. Virtual screening has suggested that estradiol cypionate may be a potential inhibitor of McFabI. Subsequently, estradiol (EST), the natural form of estradiol cypionate, was assessed for its FabI-binding and -inhibition properties. In vitro studies demonstrated that TCL and EST bind to McFabI with high affinity (KD = 0.038 ± 0.004 and 5 ± 0.06 μM respectively) and inhibit its activity (Ki = 62.93 ± 3.95 nM and 25.97 ± 1.93 μM respectively) and suppress the growth of M. catarrhalis. These findings reveal that TCL and EST inhibit the McFabI activity and thereby affect cell growth. This study suggests that estradiol may be exploited as a novel scaffold for the designing and development of more potential FabI inhibitors.

Success of artificial insemination based on expression of estrus and the addition of GnRH to an estradiol/progesterone-based protocol on pregnancy rates in lactating dairy cows

Three experiments evaluated the effects of insemination based on estrus expression or treatment with GnRH, on the time of ovulation and pregnancy rates to AI (P/AI) in dairy cows. All cows were treated with a P4 device for 8 d, estradiol benzoate at device insertion and prostaglandin F2α, estradiol cypionate and eCG at device removal. In Experiment 1, P/AI was less (P < 0.01) when all cows were inseminated at 48 h after device removal (31%) than when cows showing estrus at 48 h were inseminated at that time and those not in estrus received GnRH and were inseminated 12 h later (53%). In Experiment 2, cows in estrus by 48 h ovulated earlier than cows that were not in estrus but received GnRH and those that did not receive GnRH. Cows that were in estrus and inseminated at 48 h (47.8%) and those not in estrus at 48 h but inseminated at 60 h (53.4%) had greater P/AI (P < 0.05) than cows that were in estrus at 48 h but were inseminated at 60 h (29.7%) or inseminated at 48 h in the absence of estrus (19.4%). In Experiment 3, GnRH treatment of cows not showing estrus at 48 h and inseminated at 60 h had greater P/AI (58.5%; P < 0.05) than those not treated with GnRH but inseminated at 60 h (39.5%). Artificial insemination based on estrus expression and the inclusion of GnRH in those not in estrus increased P/AI in lactating dairy cows.

Lippia origanoides essential oil induces tocolytic effect in virgin rat uterus and inhibits writhing in a dysmenorrhea mouse model

Ethnopharmacological relevanceThe species Lippia origanoides Kunth, popularly known as “salva-de-marajó”, is used in Brazilian traditional “quilombola” communities to treat menstrual cramps and uterine inflammation. Aim of the studyEvaluate the spasmolytic activity of Lippia origanoides essential oil (LOO) on experimental models of uterine conditions related to menstrual cramps and investigate its mechanism of action. Materials and methodsVirgin rat-isolated uterus was mounted in the organ bath apparatus to evaluate the spasmolytic effect of LOO on basal tonus and contractions induced by carbachol, KCl, or oxytocin. We used pharmacological agents to verify the relaxation mechanism of LOO. The evaluation of uterine contractility in virgin rats, after treatment with LOO for three consecutive days, was carried out by the construction of a concentration-response curve with oxytocin or carbachol. The primary dysmenorrhea animal model was replicated with an injection of estradiol cypionate in female mice for three consecutive days, followed by intraperitoneal application of oxytocin. ResultsLOO relaxed the rat uterus precontracted with 10−2 IU/mL oxytocin (logEC50 = 1.98 ± 0.07), 1 μM carbachol (logEC50 = 1.42 ± 0.07) or 60 mM KCl (logEC50 = 1.53 ± 0.05). It was also able relax uterus on spontaneous contractions (logEC50 = 0.41 ± 0.05). Preincubation with glibenclamide, propranolol, phentolamine or L-NAME in contractions induced by carbachol did not alter significantly the relaxing effect of LOO. However, in the presence of 4-aminopyridine, CsCl or tetraethylammonium there was a reduction of LOO potency, whereas the blockers methylene blue, ODQ, aminophylline and heparin potentiated the LOO relaxing effect. Preincubation with LOO in a Ca2+ free medium at concentrations of 27 μg/mL or 81 μg/mL reduced the contraction induced by carbachol. The administration of LOO for 3 days did not alter uterus contractility. The treatment with LOO at 30 or 100 mg/kg intraperitoneally, or 100 mg/kg orally, inhibited writhing in female mice. The association of LOO at 10 mg/kg with nifedipine or mefenamic acid potentiated writhing inhibition in mice. ConclusionsThe essential oil of L. origanoides has tocolytic activity in rat isolated uterus pre-contracted with KCl, oxytocin, or carbachol. This effect is possibly related to the opening of potassium channels (Kir, KV, and KCa), cAMP increase, and diminution of intracellular Ca2+. This relaxant effect, probably, contributed to reduce the number of writhings in an animal model of dysmenorrhea being potentiated by nifedipine or mefenamic acid. Taken together, the results here presented indicate that this species has a pharmacological potential for the treatment of primary dysmenorrhea, supporting its use in folk medicine.

Sucrose Acetate Isobutyrate (SAIB) as a Delivery Vehicle for Estradiol and Sulpiride: Evaluation of Endocrine Responses in Geldings and Ovarian Response in Seasonally Anovulatory Mares

Sulpiride in vegetable shortening (VS) stimulates prolactin in horses for up to 10 days. Although effective, a pharmaceutical grade vehicle is needed for clinical application of sulpiride in horses. Sucrose acetate isobutyrate (SAIB), a hydrophobic polymer, may be an alternative to VS. Four in vivo experiments assessed the efficacy of SAIB for delivery of sulpiride, estradiol cypionate (ECP), and estradiol benzoate (EB). The first three studies utilized geldings to compare prolactin and luteinizing hormone (LH) concentrations between sulpiride delivered in VS and SAIB, and ECP or EB delivered in SAIB. Sulpiride stimulated (P < .01) prolactin similarly between vehicles. Geldings pretreated with EB had higher (P < .05) prolactin responses to sulpiride compared to ECP-treated geldings on days 5, 6 and 9. Both estradiol-sulpiride treatments stimulated LH with no differences between ECP and EB. Experiment 3 compared a simultaneous injection of EB-sulpiride to a non-simultaneous injection (one day apart) of EB-sulpiride. Prolactin was stimulated (P < .05) in both treatment groups, but the response lasted 2 days longer in geldings treated a day apart. Plasma LH increased (P < .01) in both groups equally for 10 days. Experiment 4 applied simultaneous and non-simultaneous EB-sulpiride treatments to seasonally anovulatory mares to induce ovarian activity. Prolactin and LH were stimulated similarly between treatments; however, non-simultaneously treated mares tended (P = .07) to have an ovarian response earlier. In conclusion, SAIB was a suitable vehicle for administration of estradiol and sulpiride and could be an alternative to VS for sustained-release drug delivery.

Effects of estradiol cypionate dose as an ovulatory stimulus on reproductive performance of lactating dairy cows during the summer season

This experiment was designed to evaluate the effects of increasing doses of estradiol cypionate (ECP) on reproductive function of lactating dairy cows during the summer. In Exp. 1, 643 lactating Holstein cows were blocked by parity and assigned to receive 1) an intravaginal P4 device (1.9 g of P4) and 2.0 mg of estradiol benzoate on day −11, 25 mg (i.m.) of dinoprost tromethamine on day −4, 1.0 mg (i.m.) of estradiol cypionate and CIDR withdrawal on day −2, followed by TAI on day 0 (n = 326; ECP-1) or 2) the same synchronization protocol with 2.0 mg of ECP on day −2 (n = 317; ECP-2). In both treatments, cows were TAI on day 0 of the protocol, and cow rectal temperature was measured on days −2, 0, and 7. In Exp. 2, 608 lactating crossbred Holstein × Gir dairy cows were blocked by parity and enrolled to the same treatments as in Exp. 1, but on day 7, cows received one viable embryo into the uterine horn. In Exp. 1, a greater percentage of ECP-2 cows were detected on estrus (81.3 vs. 91.1%, respectively). A treatment × body condition score (BCS) interaction was observed on day 60 pregnancy per AI (P/AI), as ECP-2 cows with a BCS <2.75 had a greater P/AI vs. ECP-1, but an opposite result was observed in cows with a BCS ≥2.75. Regardless of treatment, there were effects of mean rectal temperature and heat stress events on P/AI. Treatment affected the diameter of the ovulatory follicle at TAI (ECP-1 = 15.3 mm vs. ECP-2 = 14.8 mm) and a greater percentage of ECP-1 cows had larger follicles (≥16.5 mm), but ECP-2 resulted in a greater incidence of early ovulatory cows (ovulating before day 0). Therefore, follicle diameter at TAI affected P/AI on day 60 in cows receiving ECP-2 and tended to affect ECP-1 cows. A treatment effect was observed on time to estrus following ECP treatments and a reduced proportion of ECP-2 cows showed estrus at TAI. Regardless of treatment, cows detected on estrus 48 h after ECP administration had a greater P/AI on day 60 vs. cows detected on estrus 24 h. In Exp. 2, a greater percentage of ECP-2 cows were detected on estrus (68.3 vs. 81.4%, respectively). In summary, a greater dose of ECP increased the percentage of animals expressing estrus, but it did not benefit the reproductive function of lactating dairy cows during the summer, regardless if animals were assigned to a TAI or timed-embryo transfer (TET) protocol.

Does combining estradiol cypionate and GnRH for ovulation induction in recipient cows increase pregnancy rate after timed embryo transfer?

Estradiol cypionate (EC) or GnRH have been widely used for ovulation induction in timed embryo transfer (TET). EC administration increases the proportion of cows that show estrus, whereas GnRH promotes more synchronized ovulations. The aim of the present study was to evaluate the potential beneficial effects of combining EC and GnRH in TET. In experiment 1, no difference was observed on serum progesterone concentrations on Day 6 and 13 after GnRH treatment between GnRH and EC+GnRH groups. In experiment 2, pregnancy per embryo transfer (P/ET) did not differ (p = 0.69) between GnRH (62.8%) and EC+GnRH (58.7%) groups. In conclusion, combining EC and GnRH for ovulation induction does not increase progesterone secretion and pregnancy rate after TET in cattle.

Conception rate according to antral follicle count and oestrus expression in Nelore cows submitted to timed artificial insemination

Context Antral follicle count (AFC) has been related to bovine fertility and response to reproductive biotechnologies, but its relationship to oestrus expression during timed artificial insemination (TAI) is not known. Aims This study evaluated the relationship between the AFC and oestrus expression in regard to the conception rate in beef cows that received an ovulation synchronisation protocol for TAI. Methods Multiparous Nelore cows up to 40 days postpartum were evaluated by an ultrasound to determine the AFC, and were classified into low (≤15 follicles; n = 150), intermediate (≥19 and ≤26 follicles; n = 150) and high count (≥30 follicles; n = 150). AFC evaluation was performed on a random day of the oestrous cycle (Day 0). The animals received a conventional TAI protocol based on progesterone and oestradiol benzoate. On Day 8, the animals received cloprostenol, equine chorionic gonadotrophin and oestradiol cypionate, in addition to a painting in the sacrococcygeal region. On Day 10, TAI was performed, and oestrus expression was evaluated and classified as high, low or absent, according to the removal of paint. Pregnancy diagnosis was performed by ultrasound 30 days after TAI. The data were analysed using a generalised linear model and a binary logistic regression model (P &lt; 0.05). Key results Regardless of AFC, a high proportion of cows showed high oestrus expression (low 61.3%; intermediate 67.3% and high 58.7%) at the end of the TAI protocol. The conception rate was influenced by AFC (low 69.3% vs high 56.7%; P = 0.04) and oestrus expression (high oestrus: 67.3% vs no oestrus: 45.4%; P = 0.003). In addition, an interaction (P = 0.008) between AFC and oestrus expression showed that low AFC cows and high oestrus expression had the highest conception rate to TAI. Conclusion AFC and oestrus expression classification influenced the conception rate of Nelore cows in the TAI programme. In addition, the interaction of AFC with oestrus expression revealed that the best conception rate was observed in females with low AFC that expressed high-intensity oestrus. Implications The associated assessment of AFC and oestrus expression represents a strategy to increase the conception rate in TAI programmes in cattle.

Uso del CIDR y cipionato de estradiol en protocolos de sincronización sobre la presentación de celo, tasa de preñez y natalidad en borregas criollas bajo condiciones de altura

The objective of this research was to evaluate the use of the intravaginal device (CIDR) and estradiol cypionate in synchronization protocols, on oestrus presentation, pregnancy and birth rate in Creole sheep under high altitude conditions. The study was carried out in a non-reproductive season, in the peruvian highlands, using 57 ewes. Four experimental groups were formed: group T1 (n=14) and T3 (n=14), CIDR progesterone device for 7 days and 12 days, respectively; group T2 (n=15) and T4 (n=14), CIDR progesterone device for 7 days and 12 days plus 1 mg of estradiol cypionate, 24 hours after removal of the device in both groups, respectively. Estrous presentation was observed from CIDR removal to 48 hours using vasectomized rams and IATF was performed with fresh semen 48 hours after device removal. The pregnancy rate was determined by ultrasonography at 46 and 90 days after FTAI and the birth rate was recorded. The chi-square test was used for statistical analysis. There was no difference (P&gt;0.05) between groups, for estrous presentation, but there was difference (P&lt;0.05) for pregnancy rate at 46 days between groups with: T1 (42.9%), T3 (38.5%), T4 (21.4%), with respect to T2 (0%) (The difference in results are shown in Table 2). There was a difference (P&lt;0.05) for the pregnancy rate at 90 days: T1 (35.7%) and T3 (30.8%), with respect to T4 (7.1%) and T2 (0 %). The birth rate showed differences (P&lt;0.05) for T1 (28.6%) and T3 (28.6%), with respect to T2 (0%) and T4 (0%). In conclusion, a high pregnancy rate was obtained with CIDR for 7 and 12 days, compared to the use of CIDR plus estradiol cypionate. However, no births were obtained with progesterone plus estradiol cypionate treatment.

GnRH34: An alternative for increasing pregnancy in timed AI beef cows

Two experiments evaluated the effects of gonadotropin releasing hormone (GnRH) treatment on fertility of suckled Nelore beef cows treated with an estradiol/progesterone (P4)-based protocol for timed artificial insemination (TAI). Experiment 1 was designed to determine the effect of GnRH administered 34 h after P4 insert removal (GnRH34) on time of ovulation. Suckled cows (n = 34) were treated with 2 mg estradiol benzoate (EB) and an intravaginal insert containing 1.9 g of P4. Eight days later, P4 inserts were removed, and all cows received 150 μg of d-cloprostenol (prostaglandin F2 alpha analogue), 300 IU of eCG, and 1 mg of estradiol cypionate (ECP). On Day 9 (05:00 p.m.), cows were randomly distributed, according to the diameter of the pre-ovulatory follicle, in two treatments: 1) GnRH (n = 17) cows that received 10.5 μg of buserelin acetate, or 2) no further treatment (control, n = 17). Cows treated with GnRH 34 h after P4 insert removal ovulated earlier (P = 0.02) than control cows (66 ± 0.0 and 77.2 ± 4.3 h). Experiment 2 was designed to determine the effect of GnRH34 on the fertility of suckled beef cows. Nelore cows (n = 506) were treated as Experiment 1. On Day 8, cows were painted in the sacrocaudal region to identify cows that displayed estrus. On Day 9 (05:00 p.m.), cows were randomized to receive same treatment as Experiment 1, control (n = 252), or GnRH (n = 254). All cows were TAI 48 h after P4 insert removal. At TAI, estrus was evaluated, and deemed to have occurred in cows without a tail-head chalk mark (>75% paint loss). Cows treated with GnRH 34 h after P4 insert removal had greater (P = 0.01) pregnancy per AI (P/AI) than cows that only received ECP (63.0% and 50.4%). No difference (P = 0.5) was observed in the proportion of cows that displayed estrus between treatments. Furthermore, cows that displayed estrus had greater (P < 0.01) P/AI than cows that did not. Treatment with GnRH, given at 34 h after P4 insert removal, increased (P < 0.05) P/AI in cows that did not show estrus at TAI. In summary, treatment with GnRH 34 h after P4 insert removal was associated with earlier ovulation and resulted in greater P/AI in suckled Nelore cows treated with an estradiol/P4-based protocol for TAI.

Gestational losses after innovating with two embryos in a fixed-time embryo transfer program

The aim of this study was to quantify the pregnancy rate after implantation of two embryos after FTET protocols, as well as to monitor pregnancy losses until parturition, evaluating, mainly, if this strategy results in more number of animals born. Therefore, 423 multiparous recipients were selected, standardized in terms of body score, who had high-quality corpora lutea. Animals were randomly divided into two groups according to one or two embryos transferred (1 embryo = Control, n = 237; 2 embryos = Group 1, n = 186). All recipients received the same hormonal treatment, which consisted of administering, on Day 0, 2 mL of estradiol benzoate (Gonadiol, ZOETIS) + 1.9 g multidose 1st use progesterone implant (CIDR, ZOETIS); on Day 8 the implants were removed + injected 0.4 mL of estradiol cypionate (E.C.P, ZOETIS) + 1.5 mL of eCG (Novormon, ZOETIS) + 1 mL of dinoprost tromethamine (Lutalyse, ZOETIS). The animals were evaluated by ultrasonography at 30 and 60 days after embryo transfer, to diagnose the success rate and embryo losses during this period. Furthermore, information was collected on births, length of gestation, number of twin births, number of childbirth assistance and the weight of the calves. The results showed that Group 1 had better success than the Control, with higher conception rates at 30 days (68.3% vs. 53.2%, P&lt;0.001) and at 60 days (62.9% vs. 52.3%; P&lt;0 .05). The number of animals born was also higher for Group 1 (53.3% vs. 43.3%, P&lt;0.01). The percentage of twins born in Group 1 was 17.9%, and the animals had lower weight compared to the Control (34.29 + 7.36 vs 37.63 + 5.73, P&lt;0.05). The length of pregnancy and the number of assistances were similar between groups. In conclusion, the strategy adopted in this experiment suggests a considerable increase in the calf birth rate, but losses during pregnancy and their mechanisms need to be elucidated.

Estradiol cypionate treatment in suckling/weaning and estrous cycling/anestrous beef cows subjected to fixed-time artificial insemination

This study was conducted to evaluate the interaction between dose of estradiol cypionate (ECP) and ovarian status in beef cows on which different weaning/suckling regimens were imposed before fixed-time artificial insemination (FTAI). A total of 8070 estrous cycling and anestrous cows were subjected to three experiments, when calves were weaned early (Experiment 1), anti-suckling nose plates were applied for 9 or 10 days (Experiment 2), or there was continued suckling (Experiment 3). The cows were administered an estradiol/progesterone–based treatment regimen for FTAI and were treated with 0.5 or 1.0 mg of ECP im at the time of progesterone intravaginal device removal. Artificial insemination was performed from 46 to 56 h after the time of ECP treatment. Pregnancy per artificial insemination (P/AI) was affected by dose of ECP differentially in early-weaned and suckled cows. Whereas P/AI percentage was greater in early-weaned cows treated with 0.5 than 1.0 mg ECP (P < 0.05), P/AI percentage was greater for suckled cows treated with 1.0 than 0.5 mg ECP (P < 0.05). Although there were greater P/AI percentages in estrous cycling than anestrous cows (P < 0.05) when there was nose plate weaning and continuation of suckling, there was no difference between estrous cycling and anestrous cows (P = NS) when there was early weaning. Overall results indicate ECP administration affects fertility in a dose-dependent manner, suggesting an interaction between suckling and estrous cycling effects. As more critical the condition was (i.e., suckling anestrous cows), larger dose of estradiol was required.

OVULATION SYNCHRONIZATION PROTOCOLS AND FACTORS ASSOCIATED WITH PREGNANCY RATE OF ZEBU FEMALES

&lt;p&gt;&lt;strong&gt;Background.&lt;/strong&gt; Fixed time artificial insemination is an important tool for the reproductive management of cattle. &lt;strong&gt;Objective.&lt;/strong&gt; To determine the effect of two ovulation synchronization protocols and factors associated with the pregnancy rate of Zebu females using fixed time artificial insemination (FTAI) under tropical conditions. &lt;strong&gt;Methodology&lt;/strong&gt;. Data of estrous and pregnancy from 129 multiparous Zebu cows and 257 heifers were used. All animals received an intravaginal device (new or used) CIDR&lt;sup&gt;®&lt;/sup&gt; or DIB&lt;sup&gt;®&lt;/sup&gt;, which remained &lt;em&gt;in situ&lt;/em&gt; per 7 days. On the day of device removal, two treatments were established. I) Estradiol cypionate (EC; n = 192): 25 mg prostaglandin F2 alpha and 0.5 mg EC (estradiol cypionate); II) Estradiol benzoate (BE; n = 194): 25 mg PGF&lt;sub&gt;2α&lt;/sub&gt; and 24 hours later (day 8), 1 mg BE. Estrous was detected by 1-hour; three times a day, and females inseminated 54-56 hours after removal of device, using thawed semen. Pregnancy diagnosis was by transrectal palpation with real-time ultrasound, 60 days after FTAI. Data were analyzed using Chi-square tests. &lt;strong&gt;Results.&lt;/strong&gt; The overall estrous rate was 73.32%. The ovulation synchronization protocol affected the presence of estrous, where EC had a higher rate (79.39%) compared to EB (67.19%). Pregnancy rate for the females inseminated with thawed semen was 54.40%. All factors affected the pregnancy rate (p&amp;lt;0.05). &lt;strong&gt;Implications.&lt;/strong&gt; This study provides an alternative for increasing estrous and pregnancy rate of Zebu females, using EC synchronization protocol. It also shows that female type, device and BCS change influence pregnancy rate. &lt;strong&gt;Conclusion&lt;/strong&gt;. The highest rate was observed in heifers showing estrous, synchronized with a new intravaginal device, using EC and gaining body condition score.&lt;/p&gt;

COMPARAÇÃO ENTRE PROTOCOLOS COM DESMAME TEMPORÁRIO VERSUS GONADOTROFINA CORIÔNICA EQUINA APÓS TRATAMENTO COM PROGESTERONA INTRAVAGINAL VISANDO A INSEMINAÇÃO ARTIFICIAL EM TEMPO FIXO EM VACAS BOS TAURUS INDICUS

The aim of the study was to compare the reproductive efficiency of two protocols with temporary weaning (TW) of calves and one using equine chorionic gonadotropin (eCG), the synchronization of estrus and ovulation in timed artificial insemination (TAI) protocol. A total of 534 multiparous cows were distributed into three groups: temporary weaning on day 8 of the protocol group (TW8G; n = 225); temporary weaning on day 9 group (TW9G; n = 139) and equine chorionic gonadotropin group (eCGG, n = 170). TW8G received on day zero (d0) an intravaginal device with progesterone (P4; 0.558g) + estradiol benzoate (EB; 2mg, im). On d8, the device was removed with P4 + PGF (0.075mg, im) + estradiol cypionate (EC 0.5 mg, im) + removal of the calf for 48 hours. On d10, TAI was performed, and the calves returned to their mothers. The TW9G was subjected to the same protocol as the TW8G, except for the removal of the device with the P4, which occurred on the 9th, and on the d11, TAI was performed, and the calves returned to their mothers. eCGG was subjected to the same protocol as TW8G, except that on d8 it received eCG (300IU, im), on d9 estradiol benzoate and TAI on d10. The pregnancy diagnosis was made change for done at d45. The non-pregnant cows (post TAI) were re-inseminated under the observation for estrus observation (conventional AI). The remaining empty cows from conventional AI remained with the bull for another 45 days. PR after TAI was 47.1 (TW8G), 40.2 (TW9G) and 51.7% (GeCG), while PR after conventional AI was 19.3%; 31.3% and 26.8%. PR at the end of the breeding season resulted in 95.1, 90.6, and 92.3% respectively for TW8G, TW9G and eCGG. It was concluded that there was no difference in reproductive efficiency in the timed artificial insemination between the applied protocols; the use of TW or eCG can be implemented in the breeding season of beef cows.

Stability of Weekly Intramuscular Estradiol Cypionate in a Transgender Woman

Background: Transgender women often take estrogen with or without an antiandrogen to achieve the physical and physiological changes of estrogen. Estradiol may be administered through intramuscular (IM) injection weekly or every other week (1). It is thought that weekly IM estradiol may be more stable than every other week administration. The objective of this case was to evaluate the levels of IM estradiol cypionate when administered weekly. Clinical Case: A 38-year-old transgender woman with a past medical history of gender dysphoria, type 2 diabetes mellitus, hyperlipidemia, obstructive sleep apnea compliant with continuous positive airway pressure, class 3 severe obesity, anxiety, depression and a non-smoker, presented for evaluation for hormone replacement therapy (HRT). The patient wished to begin IM estradiol because she heard it was most effective. She was started on estradiol cypionate 0.5 mL (2.5 mg) IM every Sunday along with spironolactone 100 mg daily. Approximately one month later, her estradiol was 65.8 pg/mL on a Saturday, total testosterone by LC-MS/MS was suppressed to 7 ng/dL (male: 300-1080 ng/dL, female: 9 - 55 ng/dL), FSH <0.3 mIU/mL (1.5-12.4), LH <0.3 mIU/mL (1.7-8.6). We increased her estradiol cypionate to 0.8 mL (4 mg) IM every Sunday to achieve goal estradiol levels up to 100-200 pg/mL. Approximately 2 months later, estradiol was up to 160 pg/mL on a Thursday. FSH and LH remained suppressed. Spironolactone was stopped. Patient gave her estradiol dose every Sunday between 4:15-7 PM. She injected on the lateral thigh switching sides every week. At the patient’s request, blood was drawn on distinct days of the week going further from the day of injection as data collection progressed. The data we received: Monday: 153 pg/mL, Tuesday: 164 pg/mL, Wednesday: 147 pg/mL, Thursday: 122 pg/mL, Friday: 134 pg/mL, Saturday: 167 pg/mL. All labs were drawn between approximately 9:30-10:15 AM. Conclusion: Our patient wanted to see just how stable weekly IM estradiol cypionate was. We found she was able to stay within target physiologic estrogen levels, 100-200 pg/mL, throughout the week. Overall mean +/- standard deviation levels for the six samples taken between injections were 148 +/- 17 pg/mL (range: 122-167). This case provides reassurance to clinicians concerned IM estradiol may cause supraphysiologic estradiol levels.

104 Induction of cyclicity in seasonally anestrous recipient mares

Anestrous (AN) recipient mares’ natural cyclicity must be manipulated to produce foals from transferred embryos early in the year. One approach uses sulpiride to stimulate prolactin (PRL) that appears to have an important reproductive role effecting seasonality in mares. While previous research utilized sulpiride to induce ovulation (OV) in AN mares, few have transferred embryos after treatment. This study was designed to evaluate the effect of a treatment of estradiol cypionate (ECP) and sulpiride on inducing OV and subsequent pregnancy outcome in AN recipient mares of various reproductive status performed on a commercial embryo transfer farm. Anestrous recipient mares (n = 32) were randomly assigned to 4 treatment groups based on records of ovarian activity. Transitional (T, n = 8), AN (n = 11), and progesterone pre-treated (P, n = 9, received 4 mg altrenogest IM 3 wk prior) groups were treated January 20 with 50 mg of ECP IM and 3 g of sulpiride IM 24 h later. A control group (C, n = 4) of AN mares received the carrier. Jugular blood samples were collected at 0, 3, 6, 12, and 24 h post-treatment followed by daily collection for 10 d and collection every other day for 32 d thereafter and analyzed for luteinizing hormone (LH) and PRL. Ovaries were transrectally scanned every 2 to 3 d for 60 d. Embryos were transferred to 10 mares (5 T, 3 P, 2 AN) after at least the second estrous cycle up to the sixth cycle depending on their synchrony to the donor. Binomial data was analyzed via PROC GLIMMIX of SAS, and number of days to OV and hormonal data were analyzed via PROC MIXED with repeated measures. Nonparametric data were natural log-transformed and analyzed if normality was improved. Differences of least squares means were determined using the PDIFF option in SAS with ∝ ≤ 0.05 used to declare significance. There was an effect of treatment on the number of mares that achieved first OV ( P < 0.001) with 23 of 28 (82.1%) treated mares having a first OV within 22 d of treatment; and second OV ( P = 0.018) with 15 of the 23 (65.2%) mares that had a first OV achieving a second OV within 43 d. The mean number of days to first OV of T, AN, and P groups together were 32 ± 5 d earlier ( P < 0.001) than C. The transitional group ovulated sooner ( P = 0.05) than AN and tended ( P = 0.07) to ovulate sooner than P. There was an effect of the treatment-by-day interaction on plasma mean PRL ( P < 0.001) and LH ( P = 0.021) concentrations. Of the 10 embryos that were transferred, 7 (70%) resulted in a confirmed pregnancy at 60 d. Overall, the treatment protocol using ECP and sulpiride appeared to hasten OV and resulted in sustained pregnancy after embryo transfer.