The effectiveness of low-dose of eCG in timed AI Nelore (Bos indicus) heifers.

This study evaluated the efficacy of the administration of different doses of equine chorionic gonadotropin (eCG; 0 IU, 200 IU, or 300 IU) at the time of the progesterone device removal in 2-year-old Nelore (Bos indicus) heifers synchronized for fixed-timed artificial insemination (FTAI). On day 0 (D0), a total of 398 heifers received 2 mg of oestradiol benzoate i.m., 0.53 mg of cloprostenol i.m., and an eight-day previously used (second use) intravaginal device containing 1 g of progesterone (P4). Eight days later (D8), simultaneous with the P4 device removal, 0.5 mg of oestradiol cypionate i.m. and 0.53 mg of cloprostenol i.m. were administered. At the same time, heifers were randomly assigned to receive one of the following treatments: G-0 IU (n = 141; no eCG treatment), G-200 IU (n = 132; treated with 200 IU of eCG), and G-300 IU (n = 125; treated with 300 IU of eCG). FTAI was performed 48 h after the P4 device removal (D10). Ultrasonographic evaluations were performed at D0, D10, and D17. Heifers were scanned to measure the size of the largest follicle (LF), the presence, number, and size of the corpus luteum (CL), and the ovulation rate. Subsequently, at D40, the heifers underwent scanning to determine the pregnancy rate and identify any twin pregnancies. Additionally, at D70, scans were performed to assess pregnancy loss (PG). Data were analysed by orthogonal contrasts [C1 (eCG effect): control x (200 IU + 300 IU) and C2 (eCG dose effect): 200 IU × 300 IU]. On D0, CL presence was similar between the groups [G-0 IU = 65.2% (92/141), G-200 IU = 55.3% (73/132), and G-300 IU = 63.2% (79/125); p = .16]. No interactions between the presence of CL on D0 and eCG treatment were found for any of the variables (p > .05). The diameter of the LF at FTAI (D10) was not influenced by eCG treatment (p = .22) or eCG dose (p = .18). However, treatment with eCG increased the diameter of the CL at D17 (G-0 IU = 15.7 ± 0.3 mmb , G-200 IU = 16.6 ± 0.2 mma , and G-300 IU = 16.6 ± 0.3 mma ; p = .001), regardless of the dose used (p = .94). The ovulation rate was higher in heifers treated with eCG [G-0 IU = 79.4%b (112/141), G-200 IU = 90.2%a (119/132), and G-300 IU = 93.6%a (117/125); p = .002], but there was no effect of eCG dose (p = .36). Pregnancy per AI (P/AI) on D40 [G-0 IU = 32.6%b (46/141), G-200 IU = 42.4%a (56/132), and G-300 IU = 42.4%a (53/125); P = 0.05] and D70 [G-0 IU = 29.1%b (41/141), G-200 IU = 40.9%a (54/132), and G-300 IU = 40.8%a (51/125); p = .02] were higher on heifers that received eCG; however, no dose effect was observed for P/AI on D40 (p = .89) nor D70 (p = .98). Pregnancy loss between D40 and D70 tended to reduce (p = .07) in eCG-treated heifers without dose effect (p = .91). Heifers with CL at D0 presented a greater follicle diameter (LF) on D10 (With CL = 11.2 ± 0.2 mm and Without CL = 10.2 ± 0.2 mm; p = .05), CL diameter on D17 (With CL = 15.8 ± 0.03 mm and Without CL = 11.8 ± 0.6 mm; p = .01), and ovulation rate [With CL = 95.5% (233/244) and Without CL = 74.7% (115/154); p = .01]. However, no difference in pregnancy rate at D40 (p = .52) and D70 (p = .84) was found. In conclusion, eCG treatment increases ovulation and pregnancy rates of heifers submitted to a FTAI protocol. Furthermore, eCG treatment increases the diameter of the CL after FTAI and reduces pregnancy losses. No dose effect was observed, suggesting Nelore (Bos indicus) heifers respond to 200 IU of eCG treatment for FTAI.

Comparing the effect of benzalkonium chloride-preserved, polyquad-preserved, and preservative-free prostaglandin analogue eye drops on cultured human conjunctival goblet cells.

PURPOSE: To investigate the effect of benzalkonium chloride (BAK)-preserved latanoprost and bimatoprost, polyquad (PQ)-preserved travoprost, and preservative-free (PF) latanoprost and tafluprost, all prostaglandin analogues (PGAs), on human conjunctival goblet cell (GC) survival. Furthermore, to investigate the effect of BAK-preserved and PF latanoprost on the cytokine secretion from GC. METHODS: Primary human conjunctival GCs were cultivated from donor tissue. Lactate dehydrogenase (LDH) and tetrazolium dye colorimetric (MTT) assays were used for the assessment of GC survival. A cytometric bead array was employed for measuring secretion of interleukin (IL)-6 and IL-8 from GC. RESULTS: BAK-preserved latanoprost and bimatoprost reduced cell survival by 28% (p = 0.0133) and 20% (p = 0.0208), respectively, in the LDH assay compared to a negative control. BAK-preserved latanoprost reduced cell proliferation by 54% (p = 0.003), BAK-preserved bimatoprost by 45% (p = 0.006), PQ-preserved travoprost by 16% (p = 0.0041), and PF latanoprost by 19% (p = 0.0001), in the MTT assay compared to a negative control. Only PF tafluprost did not affect the GCs in either assay. BAK-preserved latanoprost caused an increase in the secretion of pro-inflammatory IL-6 and IL-8 (p = 0.0001 and p = 0.0019, respectively) compared to a negative control, which PF latanoprost did not. CONCLUSION: BAK-preserved PGA eye drops were more cytotoxic to GCs than PQ-preserved and PF PGA eye drops. BAK-preserved latanoprost induced an inflammatory response in GC. Treatment with PF and PQ-preserved PGA eye drops could mean better tolerability and adherence in glaucoma patients compared to treatment with BAK-preserved PGA eye drops.

Luteal tissue blood flow and side effects of horse-recommended luteolytic doses of dinoprost and cloprostenol in donkeys.

This study assessed luteolysis and side effects in jennies receiving standard horse-recommended doses of cloprostenol and dinoprost. Sixteen cycles of eight jennies were randomly assigned in a sequential crossover design to receive dinoprost (5 mg, i.m.) and cloprostenol (0.25 mg, i.m.) at 5-d post-ovulation. B-mode and Doppler ultrasonography were employed to assess luteal tissue size and blood flow before (-15 min and 0h) and after (0.5, 1, 2, 3, 4, 5, 6, 7, 8, 12, 24, and 48h) administering PGF2α. Immunoreactive progesterone concentrations were assayed at similar timepoints via RIA. Side effects such as sweating, abdominal discomfort, and diarrhea were scored at 15-min-intervals for 1h after PGF2α. Data normality was assessed with the Shapiro-Wilk's test. Luteal tissue size and blood flow were analyzed using PROC-MIXED and post-hoc by Tukey. Non-parametric tests analyzed side effect variables. The luteal blood flow increased overtime by 27% at 45 min and peaked by 49% at 3 h for dinoprost, and conversely, it increased by 14% at 30 min and peaked at 39% at 5h for cloprostenol (P<0.05). Luteal blood flow was reduced by 50%, 25%, and 10% on both groups at 8, 12, and 24h (P<0.05). Immunoreactive progesterone concentrations decreased in 0.5h for dinoprost and 1h for cloprostenol and gradually decreased by 48h (P<0.05). Dinoprost induced greater sudoresis scores, while cloprostenol resulted in greater abdominal discomfort and diarrhea scores (P<0.05). In conclusion, dinoprost and cloprostenol effectively induced luteolysis with distinct side effects; this could guide practitioners' case selection to use one or another PGF2α.

Additional intracervical prostaglandin reduces induction to calving time in buffaloes affected with incomplete cervical dilatation post-uterine detorsion.

Conventional induction protocol (CIP) of calving in buffaloes employs the intramuscular (IM) administration of dexamethasone (40 mg) and cloprostenol sodium (500 µg). If there is no progression in terms of cervical dilatation, then a second dose of cloprostenol sodium (500 µg) is administered intramuscularly. This protocol possesses certain demerits: (1) a wide range of response time intervals, and (2) increased risk of fetal membrane retention. Considering the cervix as a caudal continuation of the myometrium with its own contractile potential, and the limitations of CIP, we developed intracervical (IC) drug administration route in buffaloes. The proposed technique was evaluated for its use in a total of 22 cases of incomplete cervical dilatation in uterine torsion-affected buffaloes (IC-14 and IM-8). In addition to CIP, the IC group received an intracervical injection of cloprostenol sodium (500 µg) at the start of the experiment whereas the IM group received an extra intramuscular dose of cloprostenol sodium (500 µg) either after 24 h or when no progression in cervical dilatation is noticed. Surprisingly, the average response time during the experiment in the IC group was 5.8 h shorter (p < 0.000) than in the IM group (IC-5.7 ± 0.17 h vs. IM-11.9 ± 0.74 h). The duration from calving to fetal membrane expulsion (IC-12.8 ± 0.60 h vs. IM-17.5 ± 1.40 h; p < 0.002) and incidence of retention of fetal membrane were also less in the IC group (57.1% vs. 87.5%). The proposed intracervical drug administration potentiates cervical dilatation and can be regarded as a safe, effective, and feasible technique for attaining reliable results.

Low progesterone concentration in early pregnancy is detrimental to conceptus development and pregnancy outcome in horses.

High progesterone concentrations in the early luteal phase support pregnancy, whereas subphysiological progesterone concentrations delay embryonic development at least until placentation. In this study, fetal growth and development of pregnancy was investigated in pregnancies with prostaglandin F2α-induced low progesterone concentrations (PGF) in the early luteal phase and control pregnancies (CON) in the same mares (n = 12). Mares were inseminated and in PGF pregnancies received the prostaglandin F2α analogue cloprostenol (62.5 µg) on days 0-3 after ovulation to induce subphysiological progesterone concentrations; CON pregnancies remained untreated. Mares were assigned to PGF or CON treatments in alternating order and received the opposite treatment in the following year. Blood was collected and conceptus size determined repeatedly by transrectal (≤day 101) and transabdominal (>day 101) ultrasonography. After birth, foals were weighed, measured and submitted to a clinical examination. Treatment PGF resulted in fewer pregnancies than CON treatment. All foals born from CON pregnancies were healthy and mature, whereas 4/7 PGF pregnancies were either lost (one embryonic death, one abortion) or resulted in the birth of compromised foals (P = 0.018). Size of the conceptus (e.g., diameter day 49: PGF 6.6 ± 0.7, CON 7.7 ± 0.7 cm, P = 0.006) and embryo proper (e.g., crown rump length day 54; PGF 4.4 ± 0.8, CON 5.8 ± 0.6 cm, P = 0.015) differed between treatments. These size differences decreased over time and at birth PGF foals did not differ significantly from CON foals. In conclusion, reduced progesterone concentration in the early luteal phase leads to delayed conceptus growth beyond placentation and increased pregnancy loss.

Effect of cloprostenol on luteolysis and comparison of different estrus synchronization protocols in jennies.

Estrus synchronization is necessary for intensive donkey farming. Studies on estrus synchronization in jennies are, however, scarce. We aimed to investigate the susceptibility of the donkey corpus luteum to cloprostenol and design a successful estrus synchronization protocol. Firstly, the effects of different cloprostenol doses and the timing effect of cloprostenol treatment on estrous cycle was investigated. The time from treatment to luteolysis, the ovulation interval, pre-ovulatory diameter, and ovulation rates were compared between groups. Secondly, to identify the best protocol, eight estrus synchronization protocols from three categories were examined. In the first category, jennies in groups A (n = 55) and B (n = 30) received a progesterone releasing intra-vaginal device (JVID®) and cloprostenol treatment. In the second category (group C to F), jennies were pretreated with deslorelin, and then treated with JVID and cloprostenol, including groups C (n = 50), D (n = 50), E (n = 70), and F (n = 65). In the third category, jennies were treated with deslorelin and cloprostenol, including groups G (n = 40) and H (n = 40). Comparisons were made among groups regarding the degree of synchronization, ovulation, and pregnancy rates. Treatment with 0.4 mg cloprostenol on the third day following ovulation minimized the length of the luteal phase and estrous cycle. Synchronization rate varied from 60.0% to 88.6% among groups and was highest in group E. Pregnancy rates did not differ among the eight protocols. In conclusion, cloprostenol effectively induced luteolysis in jennies and a treatment protocol combining deslorelin, cloprostenol, and JVID is efficient for estrus synchronization in donkeys.

Effects of two protocols of ovulation synchronization on corpus luteum size and blood flow, progesterone concentration, and pregnancy rate in beef heifers.

The objective of this study was to evaluate the effect of 7-day estradiol-progesterone-based [Treat(C)] and 5-day Co-Synch plus progesterone [Treat(Co-Sy)] protocols on ovulation time, pre-ovulatory follicle diameter, corpus luteum (CL) size and blood flow, progesterone (P4) concentration and pregnancy rate (PR) in beef heifers. In Experiment 1, a crossover design was applied (n = 9). For Treat(C), a progesterone intravaginal (PI) device was inserted, plus 2 mg of estradiol benzoate (day 0). On day 7, 500 µg of cloprostenol plus 0.5 mg of estradiol cypionate were administered, and PI was removed. For Treat(Co-Sy), on day 0, a PI was inserted plus 100 µg gonadotropin-releasing hormone (GnRH). On day 5, PI was removed, plus 500 µg of cloprostenol and 100 µg of GnRH were administered at 69-70 h later. From day one to ovulation day, dominant follicle was evaluated by ultrasonography. On days 4 and 8 post-ovulation, CL was evaluated by color Doppler, and P4 concentration was determined by chemiluminescence. In Experiment 2, a split-plot experimental design was used. Protocols followed were the same as in Experiment 1 [Treat(C); n = 310 and Treat(Co-Sy); n = 314]. Heifers were fixed-time artificially inseminated. Pregnancy was determined on day 41. In Experiment 1, the interval between PI removal and ovulation time was different between protocols (P < 0.01). In addition, P4 concentration was related to the CL size (P < 0.001), CL blood flow (P < 0.01) and protocols (P < 0.03). In Experiment 2, PR did not differ between protocols.

Response to hormonal treatment and conception rates of Sahiwal cows subjected to fixed time artificial insemination in pastoral dairy systems.

This study aimed at determining factors influencing response of Sahiwal cows/heifers to fixed time artificial insemination protocol in pastoral systems in Kenya. Available cows/heifers were inspected for conformity to Sahiwal breed characteristics, parity, body condition score, and subsequently rectal palpation to determine pregnancy status, ovarian structures, and estimated ovarian diameter. Consequently, these animals were injected with 100 µg of gonadotrophin-releasing hormone. On days 7 and 9, only responsive cows/heifers were injected with 500 µg of cloprostenol and 100 µg of gonadorelin Acetate, respectively. On day 10, animals were inseminated and separated from bulls for 45 days and pregnancy diagnosis done after 90 days. Analysis of variance was performed to determine the effects of production system, parity, and ovarian structures on ovary diameters pre- and post-hormonal treatment. Logistic regression was used fitting a logit function to account for the binomial distribution of conception. Overall, 56.2%, 23.1%, and 20.7% of the animals had follicles (F), corpus luteum (CL), and corpus albicans (CA), respectively, at day 0, and 16.6%, 68.6%, and 14.8%, respectively, at day 7. Human and environmental factors had no influence on conception. Among the animal factors, only the ovarian structures at day 7 had a significant effect on conception. Ovaries with CL at this time were about 6 times significantly more likely to conceive than those with F. For higher conception rates, animals with ovaries with CL should be recruited into the FTAI program as they are significantly more likely to conceive than those with other ovarian structures.

Effects of different doses of estradiol benzoate used in a cervical relaxation protocol on the success of non-surgical embryo recovery and luteal function in superovulated ewes.

This study investigated the effectiveness of different doses of estradiol benzoate (EB) to promote cervical relaxation and their effects on luteal function and outcomes of non-surgical embryo recovery (NSER) in sheep. Multiparous (MULT) and nulliparous (NULL) crossbred Lacaune X Santa Inês ewes were superovulated and naturally bred. Seven days after progesterone withdrawal, females were randomly assigned to one of three distinct cervical relaxation protocols, consisting of i.m. treatment with 37.5 µg d-cloprostenol and different doses of EB: 0.0 mg (0.0EB group; n = 3 NULL and 14 MULT); 0.5 mg (0.5EB group; n = 4 NULL and 12 MULT) or 1.0 mg (1.0EB group, n = 6 NULL and 11 MULT) 16 h before NSER. All ewes received 50 IU of oxytocin 20 min before NSER (D17). Blood samples were collected and ultrasound exams (B-mode and color Doppler) were performed at two timepoints: immediately before d-cloprostenol and EB treatments and prior to NSER. Estrous behavior, corpora lutea count and NSER success outcomes were not affected by EB treatments nor parity (P > 0.05). Embryo recovery rate was greater for ewes in the 0.5EB group and in the NULL ewes (P < 0.05). Ovarian biometrics differed between the two evaluation timepoints in all groups (P < 0.05). Plasma estradiol increased over time, reaching a significant greater level in 1.0EB ewes compared to controls on D17 (P < 0.05), whereas progesterone concentrations decreased over time in all groups (P > 0.05). In conclusion, treatments did not affect NSER success but they did affect luteal function by altering P4 and E2 concentrations. Therefore, the NSER technique can be successfully performed in ewes with or without prior treatment with EB.

In Vivo Effects of Prostaglandin Analogues Application by Topical Drops or Retrobulbar Injections on the Orbital Fat of a Rat Model.

PURPOSE: To assess the in vivo effects of bimatoprost 0.03% (Lumigan®) on the orbital fat in a rat model. METHODS: Twenty rats were randomly divided into two groups: bimatoprost was administrated to the right eye by topical drops (group 1) or retrobulbar injection (group 2), and saline was administrated to the left eye by similar administration routes (controls). Four weeks later, all rats were sedated and euthanized, both orbits exenterated, and thin sections through the intraconal orbital fat were obtained. RESULTS: Average adipocyte cell count was significantly lower in the bimatoprost treated orbits (drops or retrobulbar injection, 29.5 vs. 67.5 cells per slide in the control globes, p=0.046). Fat cells were not detected in 9/20 (45%) bimatoprost treated orbits     . CONCLUSIONS: Orbits treated with bimatoprost by drops or retrobulbar injection demonstrated significant decrease in adipocytes cell count compared with controls. Bimatoprost could be an effective treatment for inactive thyroid eye disease.

Presynchronization with simultaneous administration of GnRH and prostaglandin F2α (PGF2α) 7 days prior to Ovsynch improves reproductive profile in Hariana zebu cow.

This study is aimed at assessing the impact of simultaneous administration of GnRH and prostaglandin F2α (PGF2α) 7 days prior to Ovsynch in Hariana cow. Two hundred cyclic cows (> 4 months postpartum) were assigned to control (n = 54) and pre-OV (n = 146). As per Ovsynch protocol, buserelin acetate (10 µg), cloprostenol (500 µg), and buserelin acetate (10 µg) were injected i.m. on days 0, 7, and 9, respectively, in cows irrespective of treatment. But in pre-OV cows, buserelin acetate (10 µg) and cloprostenol (500 µg) were also injected i.m. simultaneously 7 days prior to initiate the Ovsynch protocol. Artificial insemination was performed between 18 and 24 h after the 2nd GnRH of Ovsynch in both treatments. Ultrasonography and blood sampling for hormonal analysis were done on each day of treatment, on day of AI, and 12 days post-AI. Pre-OV treatment resulted to increased (45.20% vs 29.62%; P < 0.05) pregnancy outcomes and higher (P < 0.01) ovulation rate to first GnRH of Ovsynch than control. Cows showing complete luteolysis in response to PGF2α of Ovsynch were also higher (P < 0.05) in pre-OV than control. Greater (P < 0.05) synchronization rate was recorded in pre-OV than control (86.76% and 68.75%). The circulating concentrations of estradiol on day of AI and progesterone on day 12 post-AI were higher (P < 0.01) in cows diagnosed pregnant than non-pregnant in both control and pre-OV treatment. In conclusion, simultaneous administration of GnRH and PGF2α 7 days before Ovsynch improved the synchronization rate and luteal profile in terms of CL area and hence resulted in higher conception rate in Hariana zebu cow.

The vaginal and uterine blood flow changes during the ovsynch program and its impact on the pregnancy rates in Holstein dairy cows.

AIM: OvSynch is a hormonal protocol for synchronization of estrus and use of artificial insemination (AI) at an optimal time without adverse effects on the ovaries or uterus. This study investigated the use of noninvasive color Doppler ultrasound to assess changes in uterine and vaginal blood flow during the Ovsynch program for synchronization of estrus and its relation to the pregnancy rates in Holstein cows. MATERIALS AND METHODS: The experimental cows received an intramuscular dose of 10 µg of a GnRH analogue (G1), followed 7 days later with an intramuscular injection of synthetic prostaglandin F2α (P: PGF2α) analogue (500 µg cloprostenol sodium), and given a 10 µg, injection of the GnRH analogue (G2) i.m. 48 h after the PGF2α treatment, and the cows were bred 14-16 h after. Uterine and vaginal perfusion were investigated by performing transrectal Doppler ultrasonography of both the uterine and vaginal arteries in Holstein cows at different time points during the Ovsynch program to determine: peak systolic velocity (PSV), time-averaged maximum velocity (TAMV), the volume of blood flow (BFV), pulsatility index (PI), resistance index (RI), resistance impedance (S/D) and diameters of uterine (UA) and vaginal (VA) arteries. Steroid hormones were also assayed. Transrectal ultrasonography (TUS) was performed at 32 and 60 days to confirm the pregnancy per artificial insemination (P/AI). RESULTS: The uterine PSV, TAMV, and PV were greater at the time of the cloprostenol sodium and second GnRH injections (p<0.05) than at the time of the first GnRH injection. The vaginal PSV, PV were greater at the time of the cloprostenol sodium than at the time of the first and second GnRH injections (p<0.05). The receiver operating characteristic curve (ROC curve) indicated a high correlation between the uterine and vaginal blood flow and the rate of the pregnancy (p<0.05). The area under the ROC curve was 0.920 and 0.87 (p<0.05) for vaginal and uterine arteries respectively at time of G2. The serum levels of progesterone, estrogen and cortisol were correlated with the P/AI (p<0.05). The P/AI significantly decreased from 43.9 % at 32 d to 35.37 % at 60 d. CONCLUSION: These results indicate that noninvasive Doppler ultrasonography is a valid method to evaluate changes in the characteristics of uterine and vaginal blood flow in cows during the Ovsynch protocol. Furthermore, vaginal and uterine blood flow are two determinant factors for the higher conception rates in Holstein dairy cows.

Comparison of the initial ovarian response, the synchrony of oestrus and ovulation and chronic stress response after administration of 100 or 250 µg of GnRH to randomly cycling Bos indicus cattle.

OBJECTIVE: This study investigated the effects of administering saline, 100 or 250 µg of gonadotrophin releasing hormone (GnRH) on ovarian response, synchrony of oestrus and ovulation and chronic stress response in Bos indicus cattle. DESIGN: Randomised control. METHODS: Animals were either left untreated (n = 20) or on day 0 treated with an intravaginal progesterone releasing device and either saline (n = 24), 100 µg (n = 35), or 250 (n = 35) µg of GnRH, intramuscular (IM). Blood was sampled 1.4 h after administration of treatment to monitor concentrations of luteinising hormone (LH) and P4 in serum and again 5 days later. On day 5 intravaginal P4 releasing device were removed, cloprostenol was administered IM and again 8 h later. Oestrus and ovulation were then monitored with ultrasonography for 6.5 days. Hair was clipped on day 55 for analysis of hair cortisol concentrations (HCC). RESULTS: No significant differences were found between Saline and GnRH treatments in the odds of inducing a new corpus luteum (CL) and the synchrony of oestrus or ovulation. HCC did not differ significantly between treatments. Mean concentrations of LH in serum on day 0 were less in the Saline compared to 100 and 250 µg GnRH treatments but did not differ between different doses of GnRH. CONCLUSION: Mean concentrations of LH and the odds of inducing a new CL were not increased after administering 250 µg compared to 100 µg of GnRH. Animal handling events in the study did not influence HCC. Further research is needed to better optimise responses to GnRH in B. indicus cattle.

Evaluation of luteolysis, follicle size, and time to ovulation in Holstein heifers treated with two different analogs and doses of prostaglandin-F2α.

Objectives were to evaluate the effect of 2 analogs of PGF2α (cloprostenol vs. dinoprost) and 2 doses (1 injection vs. 2 injections) on luteolysis, follicle diameter, hormonal concentrations, and time to ovulation in dairy heifers. Holstein heifers were fitted with automated estrus detection devices and had their estrous cycle synchronized using PGF2α and an intravaginal insert containing progesterone. Heifers detected in estrus were blocked by weight and randomly assigned to 1 of 4 treatments in a 2 × 2 factorial arrangement: cloprostenol on d 7 after estrus (CLOx1; n = 45), cloprostenol on d 7 and 8 after estrus (CLOx2; n = 41), dinoprost on d 7 after estrus (DINx1; n = 43), or dinoprost on d 7 and 8 after estrus (DINx2; n = 44). Treatment with the first injection of PGF2α was defined as experiment d 0. Area and blood flow of corpus luteum (CL) and diameter of follicles >5 mm were recorded every 12 h from d 0 to estrus and every 6 h thereafter until ovulation. Blood was sampled every 6 h from d 0 until ovulation. Heifers treated with cloprostenol had shorter interval to luteolysis (± SEM; CLOx1 = 23.5 ± 2.2, CLOx2 = 22.9 ± 2.2, DINx1 = 32.6 ± 2.7, DINx2 = 26.4 ± 2.1 h); however, time to ovulation was not affected by treatment. A smaller proportion of heifers treated with a single injection of PGF2α underwent luteolysis compared with heifers treated with 2 injections (CLOx1 = 84.6 ± 6.2, CLOx2 = 100.0 ± 0.0, DINx1 = 59.7 ± 9.8, DINx2 = 96.3 ± 2.7%). Proportion of heifers that ovulated was smaller for DINx1 compared with other treatments (CLOx1 = 88.8 ± 5.1, CLOx2 = 100.0 ± 0.0, DINx1 = 55.2 ± 9.7, DINx2 = 94.4 ± 3.4%). Ovulatory follicle diameter was larger for DINx1 (18.2 ± 2.7 mm) compared with DINx2 (17.4 ± 2.7 mm), whereas dose did not affect the diameter of the ovulatory follicle in heifers treated with cloprostenol (CLOx1 = 17.6 ± 2.7 vs. CLOx2 = 17.8 ± 2.8 mm). Among heifers that underwent luteolysis, progesterone concentrations from 18 to 36 h after treatment were lesser in heifers treated with cloprostenol compared with those treated with dinoprost. Type of PGF2α did not affect progesterone concentrations past 36 h from treatment; however, heifers treated with 2 PGF2α injections had lesser progesterone concentrations and CL blood flow from 36 to 72 h after treatment compared with heifers that received a single PGF2α injection.

Cloprostenol enhances sexual behaviour and semen quality in growing lambs more effectively than Dinoprost.

Analogues of PGF2α have been used in boars with positive results on sexual behaviour, but limited impact on semen quality. The objective of this study was to determine whether the administration of Dinoprost tromethamine or D-Cloprostenol enhances the sexual behaviour and semen quality of sexually inexperienced growing lambs during the onset of the breeding season. The study lasted 10 weeks, beginning during the non-breeding season, with 24 sexually inexperienced Katahdin lambs (5.1 ± 0.5 months old). Three groups of eight lambs each received: (1) vehicle treatment (group CON); (2) 10 mg of Dinoprost tromethamine (group DIN); or (3) 0.15 mg of Cloprostenol dextrogy (group CLOP). The treatments were all applied im 5 min before the tests of sexual behaviour, or 20 min before the collection of semen. Sexual behaviour was evaluated twice weekly in a pen test with a non-oestrous ewe, and semen was collected once weekly with an artificial vagina. The latency to begin courtship was significantly shorter in both groups that received analogues of PGF2α than in CON lambs. The number of ano-genital sniffs, flehmens and lateral approaches was greater in both treated groups than in CON lambs (p < .05). Lambs from DIN group mounted significantly more than CLOP and CON lambs, which did not differ. However, CLOP lambs showed significantly greater mating efficiency (i.e. ejaculations/total mounts) than CON lambs, which exhibited significantly greater mating efficiency that DIN lambs. Lambs treated with CLOP produced significantly more semen volume with more mass motility than those treated with DIN and CON (without differences between DIN and CON). Overall, we concluded that the administration of cloprostenol or dinoprost before sexual evaluation in young rams enhances their sexual behaviour. Cloprostenol had greater effects than dinoprost. The administration of cloprostenol before semen collection also triggered the ejaculation of a greater volume of semen, with greater mass motility. These results open interesting possibilities to study deeply the use of simple and cost-effective treatments to improve the reproductive results of young growing rams.

Effect of travoprost, latanoprost and bimatoprost PGF2α treatments on the biomechanical properties of in-vivo rabbit cornea.

Prostaglandin F2α analogues (PGF2α), one of the most commonly prescribed classes of hypotensive agents, could decrease collagen fibril density and remodel the extracellular matrix in cornea. We hypothesized that PGF2α's would induce corneal softening, reduce the accuracy of intraocular pressure (IOP) measurement and lead to uncertainty in the effectiveness of the therapy. We determined the stress-strain behavior of rabbit cornea after PGF2α usage and evaluated the effect of biomechanical changes associated with PGF2α treatment on IOP measurements by Goldmann Applanation Tonometry (GAT). The tangent modulus decreased after PGF2α treatment, while the stromal interfibrillar spacing increased. PGF2α was shown to also affect the lateral eye with lower effect, which did not undergo direct eyedrop treatment. Significant decreases in the numerical predictions of GAT-IOP were predicted in all treated groups relative to control groups. Different PGF2α's (travoprost, latanoprost and bimatoprost) were associated with different extents of reduction in tissue stiffness and changes in corneal microstructure. PGF2α-induced changes in corneal mechanical properties could reduce the accuracy of IOP measurement and may cause an overestimation of the effect of PGF2α in lowering IOP, possibly leading to uncertainties in glaucoma management.

Hormonal protocol used for cervical dilation in ewes does not affect morphological embryo quality but reduces recovery rate and temporarily alters gene expression.

BACKGROUND: Information on the impact of hormonal protocols for cervical dilation on the quality of ovine embryos is scarce. METHODS: To compare the quality of embryos after cervical dilation protocol, ewes (n = 64) were allocated into either a treated group (100 µg estradiol benzoate intravenous and 0.12 mg cloprostenol intramuscularly, 12 hours before embryo collection plus 100 iu oxytocin intravenous 15 minutes before the collection procedure) or a control group (saline). Luteal function was analysed using ultrasonography and P4 measurement. Some collected embryos were frozen/thawed for gene expression, others were cultured in vitro, frozen/thawed for gene expression, and the remaining embryos were fixed for the apoptosis test (TUNEL test). RESULTS: The treatment reduced fluid (p=0.04) and structure (p=0.03) recovery rates, but the morphological quality, development stage, and apoptosis incidence of the embryos were not affected by treatment. The corpora lutea of the control group had greater blood perfusion (p = 0.002) and greater P4 concentrations at 6, 9, and 12 h after the treatment (p < 0.0001). The expression of BAX, BCL2, PRDX1, and HSP90 genes were not affected by the treatment. However, the embryos in the treated group had fewer NANOG and OCT4 transcripts than control embryos (p = 0.008; p = 0.006, respectively). After culture, there was no difference between the groups in any gene. CONCLUSION: The hormonal protocol for cervical dilation reduced the efficiency of embryo collection. In addition, the treatment induced luteolysis and a transient alteration of embryo gene expression, however there were no detectable changes in embryo morphological quality, development stage, or incidence of apoptosis.

Cloprostenol, a synthetic analog of prostaglandin F2α induces functional regression in cultured luteal cells of felids†.

In the present study, we investigated the effect of the synthetic analog of prostaglandin F2α (PGF2α)-cloprostenol-on cultured steroidogenic luteal cells of selected felid species over a 2-day culture period. The changes induced by cloprostenol were measured based on progesterone concentration and mRNA expression analysis of selected genes. Cloprostenol significantly reduced concentration of progesterone in cell culture medium of small luteal cells isolated from domestic cat corpora lutea (CL) at the development/maintenance stage (P < 0.05), but did not influence progesterone production in cultured cells from the regression stage. A decrease or complete silencing of progesterone production was also measured in cultured luteal cells of African lion (formation stage) and Javan leopard (development/maintenance stage). Gene-expression analysis by real-time PCR revealed that treatment with cloprostenol did not have an influence on expression of selected genes coding for enzymes of steroidogenesis (StAR, HSD3B, CYP11A1) or prostaglandin synthesis (PTGS2, PGES), nor did it effect hormone receptors (AR, ESR1, PGR, PTGER2), an anti-oxidative enzyme (SOD1) or factors of cell apoptosis (FAS, CASP3, TNFRSF1B, BCL2) over the studied period. Significant changes were measured only for expressions of luteinizing hormone (P < 0.05), prolactin (P < 0.05) and PGF2α receptors (P < 0.005) (LHCGR, PRLR, and PTGFR). The obtained results confirm that PGF2α/cloprostenol is a luteolytic agent in CL of felids and its impact on progesterone production depends on the developmental stage of the CL. Cloprostenol short-term treatment on luteal cells was associated only with functional but not structural changes related to luteal regression.

Effect of estradiol preceding and progesterone subsequent to ovulation on proportion of postpartum beef cows pregnant.

Two experiments were conducted to examine the effect of plasma concentrations of 17ß-estradiol (E2) preceding and progesterone (P4) subsequent to ovulation on proportions of beef cows pregnant following embryo transfer. Timing of ovulation (d 0) among postpartum cows was synchronized and cows that expressed estrus were removed from each study. In Experiment 1, plasma E2 concentration on d 0 was used to classify cows (n = 353) into Low, Medium, and High E2 groups. Pregnancy rate for cows with Low, Medium, or High E2 concentrations were different (P < 0.05). In Experiment 2, there were multiple administrations of PGF2α to evaluate the independent effects of Low or High E2 before ovulation and Low or Normal (no treatment) P4 after ovulation on proportions of cows pregnant. Treatment groups in Experiment 2, therefore, were: Low E2-Low P4 (LL; n = 71), Low E2-Normal P4 (LN; n = 69), High E2-Low P4 (HL; n = 74), and High E2-Normal P4 (HN; n = 73). Concentrations of P4 on d 7 subsequent to ovulation were less (P < 0.05) in cows of the HL compared to HN, and in LL compared to LN groups. Concentrations of E2 on d -2, 0, and change in E2 (d -2 to d 0) had a positive effect (P < 0.008) on pregnancy rates. In summary, relatively greater E2 concentrations preceding ovulation; and relatively greater P4 concentrations subsequent to ovulation combined with lesser E2 concentrations preceding ovulation had a positive effect on proportions of postpartum cows pregnant.

Transcriptome analysis of sheep follicular development during prerecruitment, dominant, and mature stages after FSH superstimulation.

Sheep is usually a monovular animal; superovulation technology is used to increase the number of offspring per individual and shorten generation intervals. To date, mature FSH superstimulatory treatments have been successfully used in sheep breeding, but much remains unknown about genes, pathways, and biological functions involved in follicular development. Therefore, in this study, we performed transcriptome profiling of small follicles (SFs; 2-2.5 mm), medium follicles (MFs; 3.5-4.5 mm), and large follicles (LFs; > 6 mm) in Mongolian ewes after FSH superstimulation. Furthermore, we identified differentially expressed genes and performed Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology enrichment analyses in 3 separate pairwise comparisons. We found that ovarian steroidogenesis was significantly enriched in the SFs versus MFs analysis; the associated genes, cytochrome P450 family 19 (CYP19) and Hydroxy-delta-5-steroid dehydrogenase 3 beta- and steroid delta-isomerase 1 (HSD3B1), were significantly upregulated. Moreover, proline metabolism, glutathione metabolism, and PPAR signaling pathways were significantly enriched in the LFs versus SFs analysis; the associated genes, glutamate-cysteine ligase modifier subunit (GCLM) and cystathionine gamma-lyase (CTH), were significantly upregulated, whereas peroxisome proliferator-activated receptor gamma (PPARγ) was significantly downregulated. In summary, our study provides basic data and possible biological direction to further explore the molecular mechanism of sheep follicular development after FSH superstimulation.