PGF2 Research Articles

Farrowing Induction in Swine with Prostaglandin: Effect on Farrowing Traits and Piglet Performance

The variation of gestation length in sows leads to difficulties performing farrowing supervision in commercial farms. The present study determined the efficacy of prostaglandin F2alpha (PGF2α) administration on induction of farrowing in pig. The sows (n=50) were randomly divided into two groups. In group-1, sows (n=25) were injected with placebo intramuscularly (one mL sterile water) on 113th day of gestation at 8.00 am in the morning. In group-2 (n=25), cloprostenol sodium (250 mcg) was injected intramuscularly on 113th day of gestation at 8.00 am in the morning. The parameters recorded during the experiment were gestation length, farrowing duration, total number of piglets born per litter (NTB), number of piglets born alive per litter (NBA), number of stillborn per litter, mummified foetuses per litter, birth interval (min), number of piglets alive at day 3 of lactation and piglet mortality (%) till day 3 of lactation. Gestation length was significantly (p<0.05) shorter in Group-2 compared to Group-1. Similarly, the interval from PGF2α administration to onset of farrowing was significantly (p<0.05) shorter as compared to natural farrowed sows. Farrowing duration did not differ significantly (p>0.05) between two groups. There was no effect of PGF2α administration on NTB, NBA, stillbirths, mummified fetuses. The numbers of alive piglets at day 3 of lactation were also similar between two groups (p>0.05). The PGF2α administration also resulted in increased proportion of sows that farrowed on day 114 of gestation. In conclusion, PGF2α administration on day 113 of gestation could be an option for controlled farrowing in sow without any adverse effects.

EFFECT OF GONADOTROPHIN RELEASING HORMONE ON FOLLICULAR DYNAMICS, LUTEINISING HORMONE, AND PROGESTERONE LEVELS IN BUNAJI COWS

This study evaluated the ovarian and hormonal responses of Bunaji cows to ovsynch protocol initiated at random oestrus cycle stages. Fifteen animals were arranged into three groups and treated as follows: control (n=5), 2mL normal saline; group A (n=5), 50mg Gonadotrophin releasing hormone (GnRH) on day 0 and day 9 followed by 500mg of Prostaglandin F2 alpha (PGF2a) on day 7; and group B (n=5) 100mg of GnRH on day 0 and day 9 followed by 500mg PGF2a on day 7. Ultrasound examination of the ovaries was carried out daily from d 1 to d 9 and, thereafter every 12h until ovulation was detected. Blood sampling was carried out at 30 min intervals for 6 h following the GnRH administration for determination of serum luteinizing hormone (LH) and once daily for 12 days after the injection of the first GnRH to determine plasma progesterone concentration. The ovarian response of the treated groups showed no significant difference between the two dosages of ovsynch protocol but differed significantly between the treated and the control groups. Peak values of serum LH obtained on day 0 and day 9 of GnRH administration differed significantly (P<0.05). Plasma progesterone increased among treated groups following injection of GnRH reaching a peak on day 7 compared to control, but did not differ among treated groups. In conclusion, GnRH at 50 mg and 100 mg was able to elicit adequate LH and progesterone responses that caused the disappearance of dominant follicles and, subsequent ovulation thereby increasing the reproductive efficiency of Bunaji cows.

Nigella sativa oil restores hormonal levels, and endocrine signals among thyroid, ovarian, and uterine tissues of female Wistar rats following sodium fluoride toxicity

The current study aimed to explore the possible prophylactic and therapeutic effect of Nigella sativa L. oil (NSO) against disruption of endocrine signals and injuries in the thyroid gland, ovary, and uterine tissues induced by sodium fluoride (NaF). Twenty-eight mature female Wistar rats were randomly allocated into four experimental groups (n = 7/group) as follows: control group; NaF group, orally received NaF (20 mg/kg b.wt.) daily; NSO/NaF, orally received NSO (300 mg/kg b.wt.) two weeks before being given NaF and continued throughout the experiment; and NSO+NaF group orally received NSO concurrently with NaF. Our results indicated that NSO restored hormonal balance and suppressed oxidative damage and inflammation. Moreover, the levels of triiodothyronine, thyroxine, thyroid peroxidase, estrogen (E2), progesterone, follicle-stimulating hormone, and luteinizing hormone were elevated, while prostaglandins F2-α and cortisol levels were decreased in NSO treated groups compared to NaF-intoxicated rats. As well, NSO significantly boosted levels of antioxidant molecules, and lowered lipid peroxidation of examined tissues, unlike NaF-treated group. NSO also up-regulated antioxidant enzymes, anti-apoptotic protein, zona pellucida sperm-binding protein, bone morphogenetic protein, and thyroid stimulating hormone, conversely down-regulated inflammatory cytokines, apoptotic proteins, estrogen receptor-α, estrogen receptor-β, and thyroid stimulating hormone receptors compared to NaF-intoxicated group. Additionally, NSO ameliorated tissue damage of the thyroid gland, ovary, and uterus induced by NaF. -Overall, the prophylactic group (NSO/NaF) performed better antioxidant and anti-inflammatory activities than the treated group almost in all examined tissues, which is reflected by the improvement in the structure of the thyroid, ovarian, and uterine tissues.

Mechanisms of acupuncture for primary dysmenorrhea based on PI3K/Akt/mTOR signaling pathway in rats.

To observe the effect of electroacupuncture(EA) on phosphatidylinositol-3-kinases(PI3K)/protein kinase B(Akt)/mammalian target of rapamycin(mTOR) signaling pathway of uterus tissue in rats with primary dysmenorrhea(PDM), so as to investigate its mechanisms underlying improvement of PDM. Thirty healthy non-pregnant female SD rats were randomly divided into blank, model and EA groups, with 10 rats in each group. The PDM model was established by subcutaneous injection of estradiol diphenhydrate combined with intraperitoneal injection of oxytocin. For rats of the EA group, EA(50 Hz, a tolerable current intensity) was applied to "Guanyuan"(CV4) and bilateral "Sanyinjiao"(SP6) for 20 min, once a day for 10 consecutive days. The number of writhing, wri-thing score, and writhing latency were observed. The uterine histopathological changes were observed by H.E. staining, and the ultrastructural changes of uterine tissue cells in each group were observed by transmission electron microscopy. The contents of prostaglandin E2(PGE2), prostaglandin F2α(PGF2α) and ratios of PGF2α/PGE2 in the serum and uterine tissue were detected by ELISA. The relative expression levels of PI3K, Akt and mTOR and their phosphorylation proteins in the uterine tissue were detected by Western blot and the ratios were calculated. Compared with the blank group, the number and score of writhing, latency of writhing, pathological injury score, contents of PGF2α and ratios of PGF2α/PGE2 in the serum and uterine tissue, and the levels of p-PI3K/PI3K, p-Akt/Akt and p-mTOR/mTOR in the uterine tissue were significantly increased in the model group(P<0.01, P<0.05), while contents of PGE2 in the serum and uterine tissue were reduced(P<0.05). In comparison with the model group, the number of writhing and writhing score, pathological injury score, contents of PGF2α and ratios of PGF2α/PGE2 in both the serum and uterine tissue, the levels of p-PI3K/PI3K, p-Akt/Akt and p-mTOR/mTOR were obviously decreased(P<0.05, P<0.01), whereas the writhing latency was considerably prolonged in the EA group(P<0.01), with elevated contents of PGE2 in the serum and uterine tissue(P<0.05). H.E. staining showed slight dilation of uterine glandular cavity, and severe endometrial edema with extensive cell shedding and a large number of vacuole-like degeneration, apoptosis, pyknosis or fragmentation or disappearance of the nucleus, and neutrophil infiltration in the model group, which were relatively milder in the EA group. Ultrastructural results showed irregular fibroblasts of uterine tissue cells, obvious cytoplasmic edema, reduction in cytoplasmic electron density, seriously irregular nuclei, severe edema of mitochondria with dissolved matrix, fracture and disappearance of mitochondrial crests and vacuolation, and moderate dilation of rough endoplasmic reticulum in the model group, which were milder in the EA group. EA can improve pain and uterine inflammatory response in PDM rats, which may be associated with its functions in reducing uterine PGF2α and down-regulating PI3K/Akt/mTOR signaling.

PGF2α signaling drives fibrotic remodeling and fibroblast population dynamics in mice.

Idiopathic pulmonary fibrosis (IPF) is a chronic parenchymal lung disease characterized by repetitive alveolar cell injury, myofibroblast proliferation, and excessive extracellular matrix deposition for which unmet need persists for effective therapeutics. The bioactive eicosanoid, prostaglandin F2α, and its cognate receptor FPr (Ptgfr) are implicated as a TGF-β1-independent signaling hub for IPF. To assess this, we leveraged our published murine PF model (IER-SftpcI73T) expressing a disease-associated missense mutation in the surfactant protein C (Sftpc) gene. Tamoxifen-treated IER-SftpcI73T mice developed an early multiphasic alveolitis and transition to spontaneous fibrotic remodeling by 28 days. IER-SftpcI73T mice crossed to a Ptgfr-null (FPr-/-) line showed attenuated weight loss and gene dosage-dependent rescue of mortality compared with FPr+/+ cohorts. IER-SftpcI73T/FPr-/- mice also showed reductions in multiple fibrotic endpoints for which administration of nintedanib was not additive. Single-cell RNA-Seq, pseudotime analysis, and in vitro assays demonstrated Ptgfr expression predominantly within adventitial fibroblasts, which were reprogrammed to an "inflammatory/transitional" cell state in a PGF2α /FPr-dependent manner. Collectively, the findings provide evidence for a role for PGF2α signaling in IPF, mechanistically identify a susceptible fibroblast subpopulation, and establish a benchmark effect size for disruption of this pathway in mitigating fibrotic lung remodeling.

The response of nutrient cycle, microbial community abundance and metabolic function to nitrogen fertilizer in rhizosphere soil of Phellodendron chinense Schneid seedlings.

Nitrogen (N) as an essential macronutrient affects the soil nutrient cycle, microbial community abundance, and metabolic function. However, the specific responses of microorganisms and metabolic functions in rhizosphere soil of Phellodendron chinense Schneid seedlings to N addition remain unclear. In this study, four treatments (CK, N5, N10 and N15) were conducted, and the soil physicochemical properties, enzyme activities, microbial community abundances and diversities, metabolism, and gene expressions were investigated in rhizosphere soil of P. chinense Schneid. The results showed that N addition significantly decreased rhizosphere soil pH, among which the effect of N10 treatment was better. N10 treatment significantly increased the contents of available phosphorus (AP), available potassium (AK), ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3--N) and sucrase (SU) activity, as well as fungal diversity and the relative expression abundances of amoA and phoD genes in rhizosphere soil, but observably decreased the total phosphorus (TP) content, urease (UR) activity and bacterial diversity, among which the pH, soil organic matter (SOM), AP, NH4+-N and NO3--N were the main environmental factors for affecting rhizosphere soil microbial community structure based on RDA and correlation analyses. Meanwhile, N10 treatment notably enhanced the absolute abundances of the uracil, guanine, indole, prostaglandin F2α and γ-glutamylalanine, while reduced the contents of D-phenylalanine and phenylacetylglycine in rhizosphere soil of P. chinense Schneid seedlings. Furthermore, the soil available nutrients represented a significant correlation with soil metabolites and dominant microorganisms, suggesting that N10 addition effectively regulated microbial community abundance and metabolic functions by enhancing nutrient cycle in the rhizosphere soil of P. chinense Schneid seedlings.

PGF2α induces a pro-labour phenotypical switch in human myometrial cells that can be inhibited with PGF2α receptor antagonists.

Preterm birth is the leading cause of infant morbidity and mortality. There has been an interest in developing prostaglandin F2α (PGF2α) antagonists as a new treatment for preterm birth, although much of the rationale for their use is based on studies in rodents where PGF2α initiates labour by regressing the corpus luteum and reducing systemic progesterone concentrations. How PGF2α antagonism would act in humans who do not have a fall in systemic progesterone remains unclear. One possibility, in addition to an acute stimulation of contractions, is a direct alteration of the myometrial smooth muscle cell state towards a pro-labour phenotype. In this study, we developed an immortalised myometrial cell line, MYLA, derived from myometrial tissue obtained from a pregnant, non-labouring patient, as well as a novel class of PGF2α receptor (FP) antagonist. We verified the functionality of the cell line by stimulation with PGF2α, resulting in Gαq-specific coupling and Ca2+ release, which were inhibited by FP antagonism. Compared to four published FP receptor antagonists, the novel FP antagonist N582707 was the most potent compound [Fmax 7.67 ± 0.63 (IC50 21.26nM), AUC 7.30 ± 0.32 (IC50 50.43nM), and frequency of Ca2+ oscillations 7.66 ± 0.41 (IC50 22.15nM)]. RNA-sequencing of the MYLA cell line at 1, 3, 6, 12, 24, and 48h post PGF2α treatment revealed a transforming phenotype from a fibroblastic to smooth muscle mRNA profile. PGF2α treatment increased the expression of MYLK, CALD1, and CNN1 as well as the pro-labour genes OXTR, IL6, and IL11, which were inhibited by FP antagonism. Concomitant with the inhibition of a smooth muscle, pro-labour transition, FP antagonism increased the expression of the fibroblast marker genes DCN, FBLN1, and PDGFRA. Our findings suggest that in addition to the well-described acute contractile effect, PGF2α transforms myometrial smooth muscle cells from a myofibroblast to a smooth muscle, pro-labour-like state and that the novel compound N582707 has the potential for prophylactic use in preterm labour management beyond its use as an acute tocolytic drug.

Peony Pollen Protects against Primary Dysmenorrhea in Mice by Inhibiting Inflammatory Response and Regulating the COX2/PGE2 Pathway.

Peony pollen contains multiple nutrients and components and has been used as a traditional Chinese medicine with a long history, but the effect of the treatment of primary dysmenorrhea remains to be clarified. The aim of this study is to investigate the therapeutic effect of peony pollen on primary dysmenorrhea mice and the potential mechanism. A uterus contraction model in vitro and primary dysmenorrhea mice were used to evaluate the treatment effect of peony pollen on primary dysmenorrhea. The primary dysmenorrhea mice were treated with 62.5 mg/kg, 125 mg/kg, or 250 mg/kg of peony pollen, and the writhing response, latency period, histopathological changes in the uterus, prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α) levels, and infiltration of neutrophils and macrophages were investigated. Protein expression of interleukin 1 β (IL-1β), interleukin 6 (IL-6), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), cyclooxygenase-2 (COX-2), microsomal prostaglandin-E synthase 1 (mPGEs-1), BCL2-Associated X (Bax), B-cell lymphoma-2 (BCL-2), caspase-3, and cleaved caspase-3 were detected by Western blot, and the oxidative stress related marker malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and reactive oxygen species (ROS) were evaluated. Peony pollen could attenuate spontaneous or oxytocin-induced uterus contractions in vitro. Moreover, peony pollen decreased the writhing times, prolonged the writhing latency, and reduced the pathological damage of uterine tissues. Furthermore, the inflammatory cell infiltration and the protein expression of IL-1β, IL-6, and NLRP3 were decreased. The COX-2/PGE2 pathway was inhibited; oxidative stress and apoptosis in the uterus also improved in the uterus of primary dysmenorrhea mice. Peony pollen exerts a positive effect on primary dysmenorrhea by inhibiting the inflammatory response and modulating oxidative stress and apoptosis by regulating the COX-2/PGE2 pathway.

Structures of human prostaglandin F2α receptor reveal the mechanism of ligand and G protein selectivity

Prostaglandins and their receptors regulate various physiological processes. Carboprost, an analog of prostaglandin F2α and an agonist for the prostaglandin F2-alpha receptor (FP receptor), is clinically used to treat postpartum hemorrhage (PPH). However, off-target activation of closely related receptors such as the prostaglandin E receptor subtype EP3 (EP3 receptor) by carboprost results in side effects and limits the clinical application. Meanwhile, the FP receptor selective agonist latanoprost is not suitable to treat PPH due to its poor solubility and fast clearance. Here, we present two cryo-EM structures of the FP receptor bound to carboprost and latanoprost-FA (the free acid form of latanoprost) at 2.7 Å and 3.2 Å resolution, respectively. The structures reveal the molecular mechanism of FP receptor selectivity for both endogenous prostaglandins and clinical drugs, as well as the molecular mechanism of G protein coupling preference by the prostaglandin receptors. The structural information may guide the development of better prostaglandin drugs.

GnRH analogs induce a LH peak and increase pregnancy per timed-AI in ewes

To date, there have been no studies testing the capacity of GnRH analogs and respective doses to induce a LH peak in sheep. In this sense, the present study aimed to evaluate the capacity of different synthetic forms and doses of GnRH in inducing LH release in sheep, and the effect of GnRH administration at timed artificial insemination (TAI) on pregnancy per timed-AI. In experiment 1, ewes (n = 40) received an intravaginal device (IVD) of medroxyprogesterone acetate (MPA; 60 mg) for 7 d and prostaglandin F2α analog on Day 5. On Day 7, the ewes were allocated randomly into one of eight groups (n = 5/group), which received a GnRH analog at a specific dose, as follows: lecirelin (12.5 or 25 μg), gonadorelin (50 or 100 μg), buserelin acetate (4.2 or 8.4 μg), or deslorelin (375 or 750 μg). Blood samples for LH determination were obtained at 0, 2, 4, and 6 h after GnRH and the IVDs were removed after the last blood collection. The maximal LH concentration induced by gonadorelin at doses of 50 μg and 100 μg (12.0 ± 2.4 ng/mL and 28.6 ± 7.1 ng/mL, respectively) was lower (P < 0.05) than serum LH induced by 8.4 μg of buserelin (78.9 ± 12.9 ng/mL), 375 μg and 750 μg of deslorelin (75.6 ± 7.4 ng/mL and 72.1 ± 10.6 ng/mL, respectively) and 12.5 μg and 25 μg of lecirelin (73.3 ± 17.8 ng/mL and 61.6 ± 5.9 ng/mL, respectively). However, the maximal LH concentration induced by 4.2 μg of buserelin (49.4 ± 5.9 ng/mL) was similar (P > 0.05) to the 100 μg of gonadorelin. The total release of LH (area under the curve – AUC) after treatment with 50 μg of gonadorelin (31.7 ± 5.9 ng h/mL) was lower (P < 0.05) than after other agonists. In a second experiment, 330 ewes were treated with IVD containing MPA for 7 d. Simultaneously with IVD removal, 250 μg of cloprostenol and 200 IU of eCG were administered. Then, ewes were assigned randomly to either no further treatment (control); or to receive 4.2 μg of buserelin acetate (GnRH group) at cervical TAI, which was performed with fresh semen 54 h after IVD withdrawal in all the animals. Higher pregnancy per timed-AI was observed for GnRH (50.3 %) compared to control (40.7 %). We conclude that buserelin acetate (8.4 μg), lecirelin (12.5 and 25 μg) and deslorelin (375 and 750 μg) induced a greater stimulatory effect on LH secretion than gonadorelin treatment. Furthermore, buserelin acetate treatment at TAI increased pregnancy per timed-AI in ewes previously treated with MPA and eCG.

Interaction of endocannabinoid system and cyclooxygenase metabolites with fatty acid amide hydrolase and cyclooxygenase enzyme activities on contractile responses in rat vas deferens tissue.

The endocannabinoid system and prostaglandins are important modulators in the genitourinary system. This study aimed to investigate the possible interactions between the endocannabinoid system and the cyclooxygenase (COX) pathway on rat vas deferens. For this purpose, the concentration responses of the endocannabinoid anandamide, prostaglandin F2α analog latanoprost, and prostaglandin E1 analog misoprostol on the electrical field stimulation (EFS)-induced contractile responses were obtained. The concentration responses to anandamide were obtained again in the presence of nonselective COX inhibitor flurbiprofen and prostaglandin analogs, while the concentration responses of latanoprost and misoprostol were obtained in the presence of cannabinoid receptor antagonists and fatty acid amide hydrolase (FAAH) enzyme inhibitor URB597. FAAH, COX-1, and COX-2 enzyme levels in vas deferens tissue samples were also determined. The cumulative addition of anandamide was not different from the vehicle; however, the EFS-induced contractile responses were significantly increased with the incubation of latanoprost or flurbiprofen in the prostatic portion. Flurbiprofen and misoprostol decreased FAAH enzyme levels in both portions of the vas deferens, while latanoprost induced the inhibition in the prostatic portion. The cumulative administration of latanoprost and misoprostol significantly enhanced the contractile responses in the prostatic portion. This effect of latanoprost was significantly antagonized by URB597 and AM251. The enhancing effect of misoprostol was antagonized by anandamide, URB597, AM251, and AM630. Anandamide, AM251, AM630, and URB597 decreased enzyme levels of COX-1 and COX-2 in both portions of the vas deferens. These results demonstrate an intricate crosstalk between endocannabinoids and prostaglandins in modulation of the vas deferens contractility.

Inducing cyclooxygenase-2 expression, prostaglandin E2 and prostaglandin F2α production of human dental pulp cells by activation of toll-like receptor-3, mitogen-activated protein kinase kinase/extracellular signal-regulated kinase and p38 signaling

Background/purposeBacterial infection was the major etiology for pulpal/root canal infection. This study aimed to investigate the activation of toll-like receptor-3 (TLR) on cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) and PGF2α production of human dental pulp cells (HDPCs) and associated signaling. Materials and methodsHDPCs were exposed to different concentrations of Poly (I:C) (a TLR3 activator). Cell viability was determined by 3- (4,5-Dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay and alkaline phosphatase (ALP) activity was evaluated by ALP staining. Activation of extracellular signal-regulated kinase (ERK) and p38 by Poly (I:C) was determined by immunofluorescent staining. The COX-2 protein expression was analyzed by Western blot. PGE2 and PGF2α production was measured by enzyme-linked immunosorbent assay. The mRNA expression was studied by real-time polymerase-chain reaction. Moreover, HDPCs were exposed to Poly(I:C) with/without U0126 or SB203580 treatment and analysis of COX-2 expression and prostanoid production were conducted. ResultsPoly (I:C) showed little effect on ALP activity, but decreased viability of HDPCs. It stimulated COX-2 mRNA and protein expression. Poly (I:C) induced PGE2 and PGF2α production of HDPCs. Poly (I:C) activated p-ERK, and p-p38 protein expression. Treatment by U0126 (a mitogen-activated protein kinase kinase (MEK)/ERK inhibitor) and SB203580 (a p38 inhibitor) attenuated Poly (I:C)-induced COX-2 mRNA and protein expression as well as PGE2 and PGF2α production. ConclusionTLR3 activation is involved in the infection and inflammatory responses of pulp tissues, via MEK/ERK, and p38 signaling to mediate COX-2 expression as well as PGE2 and PGF2α production, contributing to the pathogenesis and progression of pulpal/periapical diseases.

To Study the Efficacy of Intraamniotic Prostaglandin F2 Alpha versus Mifepristone and Misoprostol Combination for Mid-trimester Medical Termination of Pregnancy

Abstract Context: Aims: This study aims to compare the effectiveness, induction to abortion interval, blood loss, and side effect profile between administration of intraamniotic prostaglandin F2 alpha (PGF2α) with a combination of mifepristone and misoprostol for medical termination of pregnancy in mid-trimester. Prospective observational study. Subjects and Methods: The study was conducted by dividing the women with indicated mid-trimester abortions into two groups of 20 women each. Group-I received Tablet Mifepristone 200 mg orally on day 1 and then after 48 h, Tablet Misoprostol 400 μg given per vaginally every 4 h till abortion was completed or a maximum of 5 doses whichever was earlier. Group-II received a single injection of PGF2α (250 μg) intra-amniotically under ultrasonography guidance. Group comparisons were made using t-test/Mann–Whitney U-test for normally/nonnormally distributed continuous data, respectively, and Chi-square test for categorical variables. SPSS version 23 was used for analysis. P &lt; 0.05 was taken as the cut-off for statistical significance. Results: The success rate was 100% in both the groups. There was a significant difference in the mean induction to abortion interval between Group-I, the mean being 12.92 ± 2.68 h compared to Group-II being 33.08 ± 6.35 h (P &lt; 0.001). Group-I had a mean blood loss of 221 ± 55.15 mL, significantly more than Group-II 160 ± 25.13 mL (P &lt; 0.001). Twenty-five percent of the Group-I woman had retained products of conception with none in Group-II (P = 0.029). The pain score was better in Group II (pain score 4.4 vs. 5.7, P &lt; 0.001). Fewer women developed chills in Group II compared to Group I (0% vs. 50%, P &lt; 0.001). Conclusions: PGF2α is equally effective as a combination of Mifepristone and Misoprostol in mid-trimester abortion. Although it has a longer induction to abortion interval, it appears to be better with respect to the completeness of evacuation, lesser blood loss, and better patient tolerance.

Evaluation of later timepoints for fixed-time artificial insemination of beef heifers and cows when using sex-sorted semen

Two experiments were designed to evaluate later timepoints for fixed-time artificial insemination (FTAI) of beef heifers and cows, with the hypothesis that use of a later timepoint would allow a greater proportion of animals to express estrus prior to FTAI and result in greater conception rates among estrous females inseminated with sex-sorted semen. In Experiment 1, estrus was synchronized for 1640 heifers using the 14 d CIDR-PG protocol: insertion of an intravaginal progesterone-releasing insert (CIDR; 1.38 g progesterone) on Day −33 and removal on Day −19, and administration of prostaglandin F2α (PG; 500 μg cloprostenol sodium) on Day −3. Heifers were inseminated at one of three FTAI timepoints: 66 h, 70 h, or 74 h after PG administration. In Experiment 2, estrus was synchronized for 414 beef cows using the 7 & 7 Synch protocol: administration of PG coincident with CIDR insertion on Day −17, gonadotropin-releasing hormone (GnRH; 100 μg gonadorelin) on Day −10, and PG coincident with CIDR removal on Day −3. Cows were inseminated at one of two FTAI timepoints: 66 h or 72 h after PG administration. In both experiments, only animals that expressed estrus prior to FTAI were inseminated with sex-sorted semen. In Experiment 1, the proportion of heifers that expressed estrus prior to FTAI (66 h: 62 %; 70 h: 67 %; 74 h: 71 %) was greater when FTAI was performed at 74 h versus 66 h (P = 0.0097); however, conception rate of heifers that expressed estrus and were serviced with sex-sorted semen did not differ among treatments (P = 0.67; 66 h: 56 %; 70 h: 53 %; 74 h: 53 %). In Experiment 2, the proportion of cows expressing estrus prior to FTAI did not differ between treatments (P = 0.30; 66 h: 71 %; 72 h: 76 %). Additionally, conception rate of estrous cows inseminated with sex-sorted semen did not differ between treatments (P = 0.24; 66 h: 45 %; 72 h: 40 %). These results indicate that performing FTAI later following the 14 d CIDR-PG protocol increases the proportion of heifers that express estrus and are serviced with sex-sorted semen but does not improve conception rates. Later timing of FTAI following the 7 & 7 Synch protocol was not observed to increase the proportion of cows expressing estrus prior to FTAI or improve conception rates among estrous cows inseminated with sex-sorted semen. Together, these results provide further insight into optimal timing of FTAI when using sex-sorted semen.

182 Custom Bovine Heifer Development to Advance Onset of Puberty in a Limited-Resource Beef Cow-Calf Operation

Abstract Age at puberty in bovine heifers is controlled largely by genetic and environmental factors, among which nutrition has a major influence. This study evaluated the utility of cool-season forages for heifer development in a limited-resource beef cow-calf system. Beef heifer development was evaluated at 4 time periods: Period 1 (Birth-Weaning) heifers sucked dams until weaning, Period 2 (Weaning-Puberty) heifers grazed natural pastures and supplements in Fall and Winter, Period 3 (Puberty-Breeding) heifers grazed cool-season forages, Period 4 (Breeding-Pregnancy) heifers were maintained on Spring and Summer forages. The supplements were fed at a rate of 0.45 kg/68.2 kg. calf BW and consisted of a 1:1 ratio of cracked corn and commercial grower pellets. Cool-season pasture consisted mainly of Rye grass and clovers. Hay, water, and minerals were provided free choice. Heifer body weights were obtained at quarterly intervals. They were synchronized with two doses of prostaglandin F (PGF) 2α, 14 days apart before bull introduction on June 1st. Pregnancy was confirmed by ultrasonography at the end of breeding in August. The growth trajectory was evaluated by mixed procedures of SAS. A stair-step pattern of body weight gain was observed from birth to pregnancy. There was rapid growth pre-weaning, average daily gain (ADG) = 0.95 ± 0.0.17kg ∙heifer-1∙day-1. Limited growth during the juvenile period (ADG = 0.24 ± 0.17kg∙heifer-1∙day-1) and compensatory growth during the pre-pubertal period (ADG = 1.32 ± 0.17kg∙heifer-1∙day-1). These preliminary results indicate that limited-resource beef cow-calf producers should utilize winter forages to leverage compensatory growth in their heifer development programs. Funded by FAMU World Class Scholars Program and NIFA CBG # 2021-38821-34599

PSIII-12 The Effects of PGF2 and PGF2 Plus Gnrh on Estrous Behavior and Pregnancy Outcomes in Dairy Goats

Abstract Artificial insemination protocols depend on efficient behavioral estrus detection and insemination time in dairy goats. Here we examined the effects of two synchronization protocols, prostaglandin F2α (PGF2α; protocol 1) and PGF2 plus gonadotropin-releasing hormone (GnRH; protocol 2) on estrus behavior, body temperature, pulse frequency, pregnancy protein B (PPB) concentrations, and pregnancy rates in Alpine and Saanen goats. Forty does (3.9 ± 0.28 year) were divided into two groups (20 each) with 10 Alpine and 10 Saanen females in each group. In protocol 1 goats were injected with 10 mg/goat PGF2α on day 0 and 11. In protocol 2, each goat was injected with 10 mg PGF2α on day 0, and 43 µg GnRH on day 9 and then 10 mg PGF2 α on day 11. Estrus signs were detected 24 to 36 hours after the second dose of PGF2α. Body temperature and pulse frequency were recorded on days 11, 12, 13, and 14 after the second dose of PGF2α. Goats that showed estrus signs were naturally bred with the same breed mature buck. Blood samples were collected on days 28, 35, and 42 post-breeding (PB) to assess PPB concentrations, and ultrasonography was performed on day 50 (PB) to confirm pregnancy. The percentage of female showed estrous was higher in protocol 1 than in 2 (70% vs. 60%). Irrespective of the breed, rectal and vulval temperature was higher in the protocol 2 than 1 at day 11 after PGF2 α injection; however, it was the opposite at days 12, 13, and 14. However, the pulse frequency was greater (P &amp;lt; 0.05) in protocol 2 at all the time point. Pregnancy rates were 71.4% and 75.0% for protocols 1 and 2, respectively. Irrespective to the synchronization protocols, the pregnancy rates were greater (P &amp;lt; 0.05) in Alpine than Saanen goats. In conclusion, both PGF2 and PGF2-GnRH protocols were effective in synchronizing estrus in Alpine and Saanen goats, with minor differences in estrus response rates and pregnancy outcomes. Breed-specific variations were observed within the protocols, indicating a potential influence of breed on the efficacy of estrous synchronization. This study contributes valuable insights to goat breeding programs and promotes more efficient and sustainable livestock management practices.

179 Cost and Profit Per Pregnancy Associated with Estrous Synchronization Utilizing Estrus Detection And/Or Fixed-Time Artificial Insemination

Abstract This experiment aimed to compare synchronization cost associated with two protocols: one utilizing estrus detection (6d; PG 6-d CIDR+TAI) and one utilizing strictly fixed-time artificial insemination (FTAI; 7d; 7-d CO-Synch+CIDR). Cows and heifers (n = 657) from 10 herds in three states were grouped by days postpartum and age, and randomly assigned to one of two protocols. Cows and heifers assigned to the 6 d protocol were administered prostaglandin F2α (PGF) on d-9, CIDR insertion and administration of gonadotropin-releasing hormone (GnRH1) on d -6, and CIDR removal and PGF administration on d 0. Cows and heifers that were assigned to the 6-d protocol were subsequently grouped into three treatments based on presence and/or timing of estrus and insemination (PG1: Insemination before CIDR insertion, n = 136; PG2: Insemination after CIDR removal, n = 26; T6: Insemination at TAI, n = 166). Cows and heifers assigned to the 7-d protocol (T7: Insemination at FTAI, n = 329) were administered GnRH1 and CIDR insertion on d -7, followed by CIDR removal and PGF administration on d 0. For all animals, FTAI and GnRH2 administration occurred at 54 h (heifers) or 66 h (cows) after CIDR removal. Pregnancy was determined from d 30 to d 40 after FTAI by transrectal ultrasonography. Total cost and profit per pregnancy was calculated for herds of 30, 100, 300, and 500 females with varying estrus response and pregnancy rates. Expenditures were calculated assuming synchronization costs (PG1 = $46.15, PG2 = $75.05, T6 = $77.91, T7 = $73.72), general labor cost considering herd size and handling days, as well as estrus detection labor cost assuming $10.00 per h, a 95% overall herd pregnancy rate, a 1:40 bull:cow ratio, and average bull purchase price of $3,000.00. Revenue was estimated assuming a maximum 205-d weaning age, 1.09 kg/d gain, $200.00/45.4 kg, and 85% weaning rate. Differences in estrus response and pregnancy rate were determined using the GLIMMIX procedure of SAS (v9.4), including herd as a random variable. Estrus response was greater (P &amp;lt; 0.0001) in females assigned to the 6d (73 ± 4%) compared with the 7d (53 ± 4%) protocol; however, pregnancy success was similar among treatment groups (P = 0.32; PG1 = 45 ± 4%, PG2 = 58 ± 10%, T6 = 46±4%, T7 = 52±3%). At the observed estrus response and pregnancy rate for each treatment group, the 6d protocol resulted in a decreased cost per pregnancy compared with the 7d protocol [Table 1; herds of: 30 = ($3.53), 100 = ($5.16), 300 = ($6.58), 500 = ($7.00) females]. Additionally, using the same variables, the 6d protocol resulted in an increased profit per pregnancy compared with the 7d protocol (herds of: 30 = $3.50, 100 = $6.41, 300 = $17.27, 500 = $12.06 females). These results suggest that labor associated with estrus detection may be offset by the proportion of calves subsequently born earlier within the calving season, allowing for improvements to profitability, especially in larger herds.

PSIII-7 Effect of Time of Estrus on Conception Rate for a Sexed Semen Artificial Insemination Protocol in Multiparous Beef Cows

Abstract Sexed semen artificial insemination is a breeding technique that allows producers to shorten breeding seasons, optimize genetics through use of superior semen, create calves based on sex preference, and increase profitability. Sexed semen is a technology that sorts semen by differences in DNA content between X (female) and Y (male) bearing sperm. However, sexed semen practices have yet to be widely used in beef cows due to reduced sperm numbers, low conception rates, and increased costs. The objective of this study was to determine the effect of time of estrus upon fixed-time artificial insemination (FTAI) of sex-sorted semen on conception rate using two different estrous synchronization protocols. Multiparous commercial beef cows (n = 73) were randomized by age, body condition score (BCS), and days post-partum at the University of Arkansas Livestock and Forestry Research Station in Batesville. Both synchronization treatments (TRT) used a controlled internal drug releasing device (Eazi-breed CIDR; 1.38g progesterone) inserted intravaginally on d -14 of the protocol simultaneous to administration of prostaglandin F2α (PGF; 500µg cloprostenol sodium; Estrumate). In the first treatment (TRT 1; 7&amp;7 Synch), gonadotropin-releasing hormone (GnRH; 86µg gonadorelin; Fertagyl) was administered on d -7. In the second treatment (TRT 2; 8&amp;6 Synch), GnRH was administered on d -6. Both treatments were then administered PGF simultaneous to CIDR removal on d 0, 66 ± 2h before FTAI and administration of GnRH. Standing heat (estrus) was visually detected every 3 h for 30 min intervals between CIDR removal and FTAI. Heat detection patches were used in conjunction with visual detection of estrus. Time of estrus was signified as time of standing immobile when mounted in combination with presenting a patch score of 4 (&amp;gt;75% color removed). Time of estrus (TD) was deviated from time of FTAI and categorized into three equal time groups (Grp 1 = 0 to 11.0 h; Grp 2 = 11.01 to 22.0 h; and Grp 3 = 22.01 to 33.0 h). Conception rate (CR) was determined via ultrasound 37 ± 2 d after FTAI. Data were analyzed using the GLIMMIX procedure of SAS 9.4. CR did not differ by age of dam (P = 0.58), BCS (P = 0.48), or TRT (P = 0.83). However, TD had an effect on CR (P = 0.002); and resulted in CR of 45% (Grp 1), 87% (Grp 2), and 42% (Grp 3). In conclusion, these results indicate artificially inseminating cows with sexed semen between 11.01 and 22.0 h after time of standing estrus will increase pregnancy rates for multiparous commercial beef cattle.

292 Tandem Administration of Prostaglandin F2α and Gonadotropin-Releasing Hormone in Beef Heifers and Cows as a Convergent Presynchronization Method in the 7 &amp; 7 Synch Protocol

Abstract An experiment was designed to evaluate modifications to the 7 &amp; 7 synch protocol with the hypothesis that tandem administration of prostaglandin F2α (PG) and gonadotropin-releasing hormone (GnRH) during the presynchronization portion of the protocol would generate a convergent ovarian response among anestrous and estrous cycling females. Nulliparous (n = 153), primiparous (n = 92), and multiparous (n = 413) Angus-cross females across four locations were blocked based on parity and pre-treatment cyclicity status (presence or absence of a corpus luteum) as assessed via transrectal ovarian ultrasonography. Within block, females were randomly assigned to one of three treatments. Females assigned to the 7 &amp; 7 Synch treatment received an intravaginal progesterone-releasing insert (CIDR) and administration of PG on day 0, administration of GnRH on day 7, and administration of PG coincident with CIDR removal on day 14. Females assigned to 7 &amp; 7 Synch + G received the same treatment schedule with the modification that GnRH was administered in tandem with the PG on day 0. Females assigned to 7 &amp; 7 Synch + G + P received GnRH in tandem with PG on both day 0 and day 7 of the treatment schedule. Fixed-time artificial insemination (FTAI) was performed at 54 h after CIDR removal for nulliparous females and at 66 h for primiparous and multiparous females. Transrectal ovarian ultrasonography was performed on day 7 and day 14 to characterize the largest follicle diameter (LFD) as well as the presence/absence and number of corpora lutea (CL). Expression of estrus before FTAI was characterized in three locations using estrus detection patches (Estrotect. Approximately 75 to 90 days after FTAI, pregnancy status was determined via transrectal ultrasonography. Day 7 CL status was affected by treatment (P = 0.002), with a greater proportion of females presenting with CL on Day 7 when treated with the modified treatments (64%) as compared with the 7 &amp; 7 Synch treatment (31%). Day 14 LFD was affected by treatment (P = 0.002), with a larger average LFD among females treated with 7 &amp; 7 Synch + G + P (12.0 mm) as compared with 7 &amp; 7 Synch (11.4 mm) or 7 &amp; 7 + G (10.7 mm). Pregnancy rate to FTAI was affected by pre-treatment cyclicity status (P &amp;lt; 0.0001) and semen type (P = 0.0003) and tended to be affected by treatment (P = 0.09) with 7 &amp; 7 Synch + G + P tending to result in a greater proportion pregnant (58.86%) as compared with 7 &amp; 7 Synch (49.17%) and 7 &amp; 7 Synch + G (48.79%). Tandem administration of GnRH and PG on days 0 and 7 of the 7 &amp; 7 Synch protocol effectively generated a convergent ovarian response among anestrous and estrous cycling beef females and tended to result in increased pregnancy rates to FTAI.

291 Impact of Early Resynchronization in Combination with Color Doppler Ultrasonography on Cumulative Pregnancy Rates in Postpartum Beef Cows

Abstract The objective of this study is to evaluate a GnRH and progesterone-based early resynchronization strategy combined with color Doppler ultrasonography for early pregnancy diagnosis. Postpartum Bos taurus beef cows (n = 375) from four locations were enrolled in a completely randomized design, where cows were randomly assigned to 1 of the 2 treatments: 1) Natural Service (NS), cows were exposed to a 7-d CO-Synch + CIDR protocol followed by fixed-time artificial insemination (day 0). On day 15, cows were exposed to natural service for the remainder of the study; or 2) Early Resynchronization (ER), cows were exposed to a 7-d CO-Synch + CIDR protocol followed by fixed-time artificial insemination (day 0). On day 15, a controlled internal drug release (CIDR) device was inserted. On day 20, CIDR was removed, and pregnancy was estimated based on luteal blood perfusion using color Doppler ultrasonography. Non-pregnant cows received a 25-mg injection of prostaglandin F2α at CIDR removal and were fixed-timed-AI concurrently with a 100-μg injection of GnRH 60 to 66 h later. Pregnancy diagnosis and fetal aging were performed on day 53 using conventional ultrasonography. Pregnancy rate to the first AI was greater (P = 0.03) for NS compared with ER (70.25% vs 59.29%, respectively). Pregnancy rates for the second service were also greater (P = 0.01) for NS compared with ER (65.67 vs 42.93%, respectively). Cumulative pregnancy rates to AI did not differ between treatments (P = 0.38); however, cumulative pregnancy rates (first and second service) were greater (P &amp;lt; 0.01) for NS compared with ER (90 vs 77.73%, respectively). In conclusion, the proposed early resynchronization strategy using color Doppler ultrasonography resulted in fewer pregnancies compared with natural service as the second service strategy. Moreover, the proposed ER decreased pregnancy rates to the first insemination, indicating a detrimental effect of ER on pregnancy establishment.