Insert Removal Research Articles

MicroRNA-152-3p and MicroRNA-196a-5p Are Downregulated When Müller Cells Are Promoted by Components of the Internal Limiting Membrane: Implications for Macular Hole Healing.

Müller cells play a critical role in the closure of macular holes, and their proliferation and migration are facilitated by the internal limiting membrane (ILM). Despite the importance of this process, the underlying molecular mechanism remains underexplored. This study investigated the effects of ILM components on the microRNA (miRNA) profile of Müller cells. Rat Müller cells (rMC-1) were cultured with a culture insert and varying concentrations of ILM component coatings, namely, collagen IV, laminin, and fibronectin, and cell migration was assessed by measuring cell-free areas in successive photographs following insert removal. MiRNAs were then extracted from these cells and analyzed. Mimics and inhibitors of miRNA candidates were transfected into Müller cells, and a cell migration assay and additional cell viability assays were performed. The results revealed that the ILM components promoted Müller cell migration (p < 0.01). Among the miRNA candidates, miR-194-3p was upregulated, whereas miR-125b-1-3p, miR-132-3p, miR-146b-5p, miR-152-3p, miR-196a-5p, miR-542-5p, miR-871-3p, miR-1839-5p, and miR-3573-3p were significantly downregulated (p < 0.05; fold change > 1.5). Moreover, miR-152-3p and miR-196a-5p reduced cell migration (p < 0.05) and proliferation (p < 0.001), and their suppressive effects were reversed by their respective inhibitors. In conclusion, miRNAs were regulated in ILM component-activated Müller cells, with miR-152-3p and miR-196a-5p regulating Müller cell migration and proliferation. These results serve as a basis for understanding the molecular healing process of macular holes and identifying potential new target genes in future research.

Postponing TAI in beef cows with small preovulatory follicles

The aims of this study were (1) to establish an optimal cut-off point for evaluating the effect of the preovulatory follicle (POF) diameter in timed AI (TAI) programs, and (2) to evaluate the effect of postponing TAI in cows with smaller follicles on pregnancy per AI (P/AI). In Study 1, Nelore cows (n = 426) were subjected to an estradiol-progesterone (P4) based TAI protocol. The diameter of POF was measured at TAI, 48 h after P4 insert removal. From the ROC curves for determining the relationship between the POF diameter and pregnancy, the cut-off was 11 mm (P < 0.001). Cows with larger POF had greater (P < 0.05) P/AI (62.5%) than cows with smaller POF (34.8%). In Study 2, Nelore cows (n = 1257) were subjected to the same TAI protocol as in Study 1. Before TAI, cows were separated according to POF diameter in three groups: (1) Larger POF (LP, n = 873; POF ≥11 mm), (2) Smaller POF 0 h (SP0, n = 195; POF <11 mm), and (3) Smaller POF 24 h (SP24, n = 189; POF <11 mm). Cows in the LP and SP0 were TAI at 48 h and cows in the SP24 group were TAI at 72 h after P4 insert removal. Cows in the LP group had the greatest (P < 0.05) P/AI (60.25%), followed by cows in the SP24 group (41.8%), while cows in the SP0 group had the lowest P/AI (31.8%). In conclusion, cows with smaller follicles have lower P/AI, but postponing the TAI by 24 h in these cows increases P/AI.

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.

Estradiol cypionate administered at the end of a progesterone-based protocol for FTAI induces ovulation and improves postovulatory luteal function and uterine environment in anestrous beef cows

The objective of this study was to evaluate the effect of the administration of estradiol cypionate (ECP) at the end of an estradiol and progesterone-based protocol for fixed time artificial insemination (FTAI) on ovarian response and uterine function in postpartum anestrous beef cows. Multiparous suckled cows were randomly assigned to receive ECP at doses of 0 (control, n = 15), 0.5 (n = 15) or 1.0 mg (n = 15) im at the time of progesterone intravaginal insert removal. Serum 17β-estradiol concentrations at 24 h after insert removal were greater (P < 0.05) in both ECP treatments than in controls. No differences in estradiol were found between 0.5 mg and control cows (P > 0.1) from 48 h after insert removal until ovulation, although greater (P < 0.05) concentrations were maintained until ovulation in 1.0 mg ECP treated cows. Maximum 17β-estradiol concentration attained in each female was greater as ECP dose was greater (10.4 ± 0.4, 11.8 ± 0.5 and 13.5 ± 0.7, for control, 0.5 and 1.0 mg ECP treated cows, respectively; P < 005). Proportion of cows that ovulated tended to be greater (P = 0.06) in ECP treated than in control cows. Ovulation occurred earlier and the size of the ovulatory follicle was smaller (P < 0.05) for 1.0 mg but not for 0.5 mg (P > 0.1) when compared with control cows. After ovulation (Day 13 and 14), serum progesterone concentrations were greater (P < 0.05) in 0.5 and 1.0 mg ECP than control cows. Uterine environment on Day 6 after ovulation was affected by treatment; transcript expression of three of nine evaluated genes (i.e., estrogen, IGF-1 and insulin receptors genes) were upregulated (P < 0.05) after ECP treatment. In conclusion, ECP administration at progesterone insert removal in anestrous cows i) induces greater serum estradiol concentrations and tended to induce greater ovulation rate, ii) acts in a dose-dependent manner, as ECP dose increases ovulation occurs earlier and the size of the ovulatory follicle is smaller, iii) improves postovulatory luteal function and affects uterine gene expression. Altogether, this information contributes with the understanding of the effect of preovulatory estradiol exposure on ovulation and postovulatory ovarian and uterine function in anestrous beef cows.

In Vitro Effects of Cyclic Dislodgement on Retentive Properties of Various Titanium-Based Dental Implant Overdentures Attachment System.

The purpose of this study was to evaluate the change in the retentive forces of four different titanium-based implant attachment systems during the simulation of insert–removal cycles in an artificial oral environment. Five types of titanium-based dental implant attachment systems (Locator, Kerator, O-ring, EZ-Lock, and Magnetic) were studied (n = 10). The specimens underwent insert–removal cycles in artificial saliva, and the retentive force was measured following 0, 750, 1500, and 2250 cycles. Significant retention loss was observed in all attachment systems, except the magnetic attachments, upon completion of 2250 insertion and removal cycles, compared to the initial retentive force (p < 0.05). A comparison of the initial retentive forces revealed the highest value for Locator, followed by the Kerator, O-ring, EZ-Lock, and Magnetic attachments. Furthermore, Kerator demonstrated the highest retentive loss, followed by Locator, O-ring, EZ-Lock, and Magnetic attachments after 2250 cycles (p < 0.05). In addition, the Locator and Kerator systems revealed significant decrease in retentive forces at all measurement points (p < 0.05). The retention force according to the insert–removal cycles were significantly different according to the types of dental implant attachment systems.

Effect of presynchronization with prostaglandin F2α before the 5-d timed AI protocol on ovarian responses and pregnancy in dairy heifers

The objectives were the determine the effects of presynchronization with PGF2α 2 days before the 5-d timed artificial insemination (AI) protocol on ovarian responses and pregnancy per AI (P/AI) in dairy heifers. The hypothesis was that PGF2α would induce responsive heifers to be in proestrus at the initiation of the timed AI protocol, which was expected to improve ovulatory responses and P/AI. Weekly cohorts of Holstein heifers were blocked by age and, within block, randomly assigned to remain as control (CON; n = 255) or receive PGF2α on experiment Day −10 (PG; n = 255). All heifers were subjected to the 5-d timed AI protocol (Day −8, GnRH + intravaginal progesterone controlled internal drug release insert; Day −3, PGF2α and insert removal; Day −2, PGF2α; and Day 0, GnRH and AI). A subset of 22 blocks of heifers (n = 43) had their ovaries scanned by ultrasonography on experiment Days −8, −3, 0, and 2 and blood was sampled and analyzed for concentrations of progesterone on experiment Days −8, −7, −5, and −3. Pregnancy was diagnosed on experiment Days 32 and 60. On the day of the first GnRH of the timed AI protocol, PG heifers had smaller concentration of progesterone in plasma (CON = 4.5 ± 0.5 vs. PG = 0.5 ± 0.5 ng/mL), but larger follicular diameter (CON = 9.1 ± 0.5 vs. PG = 11.0 ± 0.5 mm), and a greater proportion of them had a follicle with at least 8.0 mm in diameter (CON = 61.9 vs. PG = 90.9%) than CON heifers, which resulted in increased ovulation to GnRH (CON = 19.0 vs. PG = 86.3%). Ovulation to the initial GnRH of the protocol increased as the concentration of progesterone in plasma decreased, from less than 20% when progesterone was greater than 5.0 ng/mL to more than 65% when progesterone was less than 1.0 ng/mL. More CON than PG heifers spontaenously ovulated before the day of timed AI. Detection of estrus on the day of timed AI did not differ between treatments (CON = 50.9 vs. PG = 46.6%), but P/AI on Days 32 (CON = 52.9 vs. PG = 61.1%) and 60 (CON = 49.0 vs. PG = 57.1%) after insemination tended to be greater for PG than CON; however, the benefit to presynchronization was observed in heifers inseminated with conventional (CON = 54.7 vs. PG = 67.4%), but not in heifers inseminated with sex-sorted semen (CON = 50.9 vs. PG = 52.8%). Administration of PGF2α 2 days before initiating the timed AI protocol induced heifers to be in proestrus, which enhanced ovulation to the initial GnRH and favored pregnancy per AI, particularly in heifers inseminated with conventional semen.

Influence of small doses of gonadotropin-releasing hormone following controlled internal drug-release insert removal on reproductive parameters in beef cattle subjected to a fixed-time artificial insemination protocol

ABSTRACT Heifers and cows that exhibit estrus before fixed-time AI have increased concentrations of estradiol and greater conception rates compared with those that do not. Our objective was to determine whether small doses of gonadotropin-releasing hormone following controlled internal drug-release insert removal would affect estradiol concentrations, estrus expression, or pregnancy success. Beef cattle (n = 247) were synchronized using the 7-d CO-Synch+CIDR protocol and assigned to 1 of 3 treatment groups (0 μg,10 μg, or 5 + 5 μg of gonadotropin-releasing hormone). Animals were observed for estrus, blood samples were collected, and animals were bred by appointment. Concentrations of estradiol were influenced by time (P

Vaginal Hysterectomy with Salpingectomy for Essure Insert Removal

Study ObjectiveTo evaluate the feasibility of an en-bloc salpingectomy at the time of vaginal hysterectomy for removal of Essure inserts. DesignProspective observational study (Canadian Task Force classification II-1). SettingMonocenter study at the Conception University Hospital Center, Marseille, France. PatientsWomen seeking removal of the Essure device and candidate for vaginal hysterectomy from January 1, 2017 to January 31, 2018. InterventionsPatient underwent a total hysterectomy and bilateral salpingectomy by the vaginal route (VH-S) with en-bloc removal of each hemiuterus with the ipsilateral fallopian tube, thereby allowing for removal of the Essure inserts without fragmentation. Measurements and Main ResultsTwenty-six VH-S were performed. There was no converted case to laparoscopy or laparotomy because of issues regarding feasibility or complications. Removal of each hemiuterus with the ipsilateral tube as a single unit was feasible in all cases. There was 1 Clavien-Dindo grade 1 perioperative complication: a bladder injury that required 10days of urinary catheterization. There were 2 grade 2 postoperative complications: 1 case of metrorrhagia of a granuloma on the vaginal fundus that was treated with silver nitrate and 1 case of acute urinary retention that required urinary catheterization for 24hours. ConclusionPerforming a VH-S with en-bloc removal of the hemiuterus with the ipsilateral tube without fragmentation orsectioning of the Essure inserts appears to be feasible. The vaginal route can hence be an approach for women who undergo hysterectomy during Essure insert surgery removal.

Prediction of the efficacy of dinoprostone slow release vaginal insert (Propess) for cervical ripening: A prospective cohort study.

To evaluate factors predictive of the success of dinoprostone slow release vaginal insert for cervical ripening. A total of 169 women who underwent cervical ripening with dinoprostone slow release vaginal insert were included in the study cohort. The correlation between parameters present before cervical ripening with dinoprostone slow release and its success, as well as complications and adverse outcomes were analyzed. Dinoprostone slow release vaginal insert was successful in achieving vaginal delivery in 148 of 169 (87.6%), while sufficient ripening was achieved in 140 (83%) cases. Factors associated with successful vaginal delivery were multiparity and younger gestational age at delivery. Factors predictive of the success of cervical ripening with dinoprostone slow release vaginal insert were lower body mass index (BMI), higher parity and perceived contractions prior to insertion. Intrauterine growth restriction was associated with a significant risk for dinoprostone insert removal. Neonatal outcomes were similar in cases of successful or failed ripening. The success of cervical ripening with dinoprostone slow release vaginal insert can be predicted by factors that can be recognized at admission.

60 Reproductive Performance After Timed Artificial Insemination Followed by Timed Embryo Transfer of In Vitro-Produced Embryos in Beef Cattle

The combined use of timed AI (TAI) and embryo transfer (TET) has the potential to increase reproductive efficiency in beef cattle. This study evaluated reproductive performance in beef cattle after TAI followed by TET of in vitro-produced embryos at the onset of the breeding season. A total of 476 multiparous non-suckling Bos taurus females (body condition scores of 2.9 ± 0.4 on 1 to 5 scale) were oestrous synchronized with 2 mg of oestradiol benzoate (IM) and a 1.9-g intravaginal progesterone release device (Day –11), which was removed on Day –2, followed by 0.48 mg of sodium cloprostenol, 400 IU of eCG, and 0.5 mg of oestradiol cypionate (IM). In experiment I [no heat detection (HD), or no HD, n = 387], TAI was carried out 48 h later (Day 0), whereas in experiment II (after HD, n = 89), AI was performed 12 h after the onset of oestrus up to 48 h after intravaginal insert removal, when remaining females were inseminated (Day 0). Day-7 blastocysts produced by IVF from abattoir-derived oocytes were individually transferred (TET) 7 days after TAI (Day 7) to 186/387 and 44/89 females in experiments I and II, respectively, ipsilateral to the corpus luteum. Then, fertile mature Bos taurus bulls were introduced on Day 12 into the herds (1:25) up to Day 90. Determinations of pregnancy outcome after TAI, TAI+TET or natural mating, twinning rates, and pregnancy losses were done by ultrasonography and rectal palpation on Days 30, 60, and 125. Data were analysed by the Chi-squared test (P &lt; 0.05). Pregnancy rates (Day 30) were lower after TAI (104/201, 51.7%) than after TAI+TET (126/186, 67.7%) with no HD (experiment I), but similar between TAI (32/45, 71.1%) and TAI+TET (30/44, 68.2%) after HD (experiment II). Twinning rates were lower in TAI groups with no HD (6/104, 5.8%) and after HD (2/32, 6.2%) than in TAI+TET groups with either no HD (42/126, 33.3%) or with HD (14/30, 46.7%). Overall pregnancy was similar between groups after the end of the breeding season: 90.0% (181/201) and 90.3% (168/186) for TAI and TAI+TET with no HD, and 84.4% (38/45) and 84.1% (37/44) for TAI and TAI+TET after HD. Pregnancy losses were higher after TAI+TET with no HD (27/126, 21.4%) than TAI+TET after HD (3/30, 10.0%), and TAI with (2/32, 6.3%) or without (9/104, 8.7%) HD. The TAI+TET with no HD resulted in fewer fetuses per served (0.69) and pregnant (1.30) female than TAI+TET after HD (0.89 and 1.44), whereas TAI with no HD had fewer fetuses than TAI after HD per served (0.50 v. 0.69) but not per pregnant female (1.05 v. 1.03), with both being lower than the TAI+TET groups. In summary, TET after TAI with no HD increased pregnancy and twinning rates. Also, heat detection increased pregnancy rates after TAI and twinning rates after TAI+TET. The TAI+TET combination may be advisable for reproductive schemes with no HD, whereas no benefit of TAI+TET was seen over TAI regarding pregnancy rate if TAI is coupled with HD, but HD may increase prolificacy after TAI+TET. The economics of the use of TAI+TET is under evaluation, by assessing calving, weaning, and postnatal weight gain rates between groups.

Two split-time artificial insemination programs in suckled beef cows1,2

Our objective was to determine which of 2 split-time AI programs applied to suckled beef cows would result in greater pregnancy risk. Suckled beef cows (n = 1,062) at 12 locations in 4 states (CO, KS, MY, and WA) were enrolled. Cows were treated on d -7 with a progesterone insert concurrent with 100 µg GnRH and on d 0 with 25 mg PGF plus removal of the insert. Estrus-detection patches were affixed to cows at insert removal. The study was designed as a completely randomized experiment of 2 treatment combinations. Within location and balanced for parity (primiparous vs. multiparous), cows were assigned randomly to 2 treatment times (55 vs. 65 h after CIDR insert removal) at which time estrus-detection patches were assessed. Estrus was defined to have occurred when an estrus-detection patch was > 50% colored (activated). Cows determined to be in estrus were inseminated at either 55 or 65 h, whereas the residual nonestrous cows in both treatment times received GnRH at 55 or 65 h but were inseminated 20 h later at 75 or 85 h, respectively. Pregnancy outcomes were determined at 36 d after AI and at the end of the breeding season. Thus, pregnancy outcomes of interest were compared between the 55 + 75-h treatment combination and that of the 65+85-h combination. Expression of estrus was greater ( = 0.001) by 65 h after PGF than by 55 h (62.0% vs. 41.9%), respectively, and this proportion was influenced by parity (time x parity interaction; = 0.006). As a result, proportionally more ( < 0.001) cows received the timed AI at 75 than 85 h (59.4% vs. 40.6%). Similar proportions of cows not in estrus by 55 or 65 h were detected in estrus by 75 or 85 h (40.1% vs. 39.3%), respectively. The cumulative proportion of cows in estrus by 75 h was less ( < 0.001) than that by 85 h (66.7% vs. 76.7%), respectively. Pregnancy risks at 36 d differed among treatments, with cows detected in estrus and inseminated at 55 or 65 h having greater pregnancy risks than their time-inseminated herd mates at 75 or 85 h (62.3% vs.49.7%), respectively. Overall pregnancy risk for cows in the 65+85-h treatment combination was greater at 36 d than for cows in the 55 + 75-h treatment combination (61.0% vs. 51.4%), respectively. We conclude that the 65 + 85-h treatment combination produced more pregnancies than the 55 + 75-h combination, but its implementation may be somewhat less convenient in terms of cow handling times.

Resynchronization of ovulation protocols for dairy cows including or not including gonadotropin-releasing hormone to induce a new follicular wave: Effects on re-insemination pattern, ovarian responses, and pregnancy outcomes.

Our objectives were to evaluate the pattern of re-insemination, ovarian responses, and pregnancy per artificial insemination (P/AI) of cows submitted to different resynchronization of ovulation protocols. The base protocol started at 25 ± 3 d after artificial insemination (AI) and was as follows: GnRH, 7 and 8 d later PGF2α, GnRH 32 h after second PGF2α, and fixed timed AI (TAI) 16 to 18 h after GnRH. At 18 ± 3 d after AI, cows were randomly assigned to the G25 (n = 1,100) or NoG25 (n = 1,098) treatments. The protocol for G25 and NoG25 was the same, except that cows in NoG25 did not receive GnRH 25 ± 3 d after AI. At nonpregnancy diagnosis (NPD), 32 ± 3 d after AI, cows from G25 and NoG25 with a corpus luteum (CL) ≥15 mm in diameter and a follicle ≥10 mm completed the protocol (G25 CL = 272, NoG25 CL = 194), whereas cows from both treatments that did not meet these criteria received a modified Ovsynch protocol with P4 supplementation [controlled internal drug release insert plus GnRH, controlled internal drug release insert removal, and PGF2α 7 and 8 d later, GnRH 32 h after second PGF2α, and TAI 16 to 18 h after GnRH (G25 NoCL = 53, NoG25 NoCL = 78)]. Serum concentrations of progesterone (P4) were determined and ovarian ultrasonography was performed thrice weekly from 18 ± 3 d after AI until 1 d after TAI (G25 = 46, NoG25 = 44 cows). A greater percentage of NoG25 cows were re-inseminated at detected estrus (NoG25 = 53.5%, G25 = 44.6%), whereas more cows had a CL at NPD in G25 than NoG25 (83.7 and 71.3%). At 32 d after AI, P/AI was similar for G25 and NoG25 for inseminations at detected estrus (38.4 and 42.9%), TAI services for cows with no CL (40.4 and 36.7%), and for all services combined (39.6 and 39.0%). However, P/AI were greater for cows with a CL in G25 than NoG25 (40.6 and 32.8%) that received TAI. More cows ovulated spontaneously or in response to GnRH for the G25 than the NoG25 treatment (70 and 36%) but a similar proportion had an active follicle at NPD (G25 = 91% and NoG25 = 96%). The largest follicle diameter at NPD (G25 = 15.0 ± 0.4 mm, NoG25 = 16.5 ± 0.6 mm) and days since it reached ≥10 mm (G25 = 4.0 ± 0.3 d, NoG25 = 5.8 ± 0.6 d) were greater for the NoG25 than G25 treatment. For cows with a CL at NPD, CL regression after NPD, ovulation after TAI, and ovulatory follicle diameter did not differ. In conclusion, removing the first GnRH of a modified Resynch-25 protocol for cows with a CL at NPD and a modified Ovsynch protocol with P4 supplementation for cows without a CL at NPD resulted in a greater percentage of cows re-inseminated at detected estrus and a similar proportion of cows pregnant in spite of reduced P/AI for cows with a CL at NPD.

Increasing estrus expression in the lactating dairy cow

Using an activity monitoring system (AMS) equipped with an accelerometer, 2 experiments were conducted to test the hypotheses that (1) enhancing progesterone before inducing luteolysis or (2) exposing cows to estradiol cypionate (ECP) or testosterone propionate (TP) after luteolysis would increase occurrence and intensity of estrus. Our goal was to determine if more cows could be detected in estrus by an AMS compared with other estrus-detection aids. In experiment 1, cows (n=154) were fitted with both an AMS collar and a pressure-sensitive, rump-mounted device (HeatWatch; HW) and assigned to 3 treatments: (1) no CL + progesterone insert (CIDR) for 5d, (2) CL only, or (3) CL + 2 CIDR inserts for 5d to achieve a range in concentrations of progesterone. Prostaglandin F2α was administered to all cows upon CIDR insert removal or its equivalent. Progesterone concentration up to 72h posttreatment was greatest in CL + 2 CIDR, followed by CL only, and no CL + CIDR cows. Estrus occurred 14 to 28h earlier in no CL + CIDR compared with CL-bearing cows. Estrus intensity was greater for CL + 2 CIDR than for CL-only cows. The AMS and HW detected 70 and 59% of cows defined to be in estrus, respectively. In experiment 2, cows (n=203) were equipped with both an AMS and a friction-activated, rump-mounted patch (Estrotect patch) and assigned to receive 1mg of ECP, 2mg of TP, or control 24h after PGF2α. Concentrations of estradiol 24 and 48h after treatment were greater in ECP cows compared with controls. Estrus expression detected by AMS or patches in cows defined to be in estrus tended to be greater or was greater for ECP compared with controls, respectively. Compared with controls and in response to TP or ECP, estrus occurred 8 to 18h earlier and was of greater intensity for ECP cows, respectively. The AMS and patches determined 73 and 76% of cows defined to be in estrus, respectively. Of cows exposed to the AMS, HW, or patches, 70, 61, and 75%, respectively, were detected in estrus and more than 93% of these subsequently ovulated. In contrast, of the residual cows not detected in estrus, 62 to 77% ovulated in the absence of detected estrus. Only ECP was successful in inducing more expression and intensity of estrus, and proportions of cows detected in estrus exceeded 80%. Given the large proportion of cows equipped with AMS collars ovulating in the absence of estrus, further research is warranted to determine if more pregnancies can be achieved by inseminating those cows not detected in estrus at an appropriate time when PGF2α is administered to induce luteolysis.

The acute effect of intravenous lipopolysaccharide injection on serum and intrafollicular HDL components and gene expression in granulosa cells of the bovine dominant follicle

The aim of this study was to evaluate the effect of an acute systemic inflammatory response induced by lipopolysaccharide (LPS) in the serum and follicular fluid (FF) high-density lipoprotein (HDL) components, hormone concentrations and granulosa cell gene expression. For this purpose, twenty non-lactating Jersey dairy cows were submitted to a progesterone (P4) – estradiol (E2) based synchronization protocol. Cows received a single i.v. dose of LPS (2.5 μg/kg of body weight) or saline solution (CTL Group) 2 h after P4 insert removal. Blood, granulosa cells and FF samples were collected six hours after LPS injection. Five hours after LPS injection rectal temperature was increased in LPS (P < 0.0001, 40.4 ± 0.1 °C) compared to the CTL cows (38.8 ± 0.1 °C). Serum PON1 activity was reduced by LPS injection (130.2 ± 5.1 vs. 99.6 ± 3.3 U/mL; P < 0.001), as well as HDL-cholesterol concentrations (70.3 ± 5.3 vs. 50.1 ± 6.2 mg/dL; P < 0.05). The FF E2 and P4 concentrations were not different between groups (P > 0.05). The PON1 activity in the FF was also decreased by LPS injection (P = 0.01). In comparison to CTL group, cows injected with LPS had a ten fold reduction in STAR, TLR4 and TNF mRNA expression (P < 0.05). In conclusion, an intravenous LPS challenge in cows induced an acute systemic inflammatory response reducing HDL and its components in serum but not in the FF. Only PON1 activity serum reduction was reflected in the FF in the short term. Additionally, steroidogenic and inflammatory genes had reduced expression in the granulosa cells.

Cloprostenol sodium and dinoprost tromethamine result in similar artificial insemination pregnancy rates in Bos taurus, Bos indicus, and Bos indicus × Bos taurus cattle synchronized with a Select Synch and CIDR plus timed–artificial insemination protocol

<h2>ABSTRACT</h2> Two experiments were conducted to evaluate breed [Angus (AN), Brahman (BR), and varying percentages of BR × AN breeding] and prostaglandin F_2α (PGF) type [dinoprost tromethamine (dinoprost) vs. cloprostenol sodium (cloprostenol)] in suckled cows (Exp. 1; n=504) and 2-yr-old virgin heifers (Exp. 2; n=309) synchronized with a Select Synch + controlled intravaginal drug-releasing insert and timed-AI protocol (SSCT). On d −7, cows and heifers received gonadotropin-releasing hormone and controlled intravaginal drug-releasing inserts. At controlled intravaginal drug-releasing insert removal (d 0), cows were stratified by BCS, days postpartum, parity, and breed; heifers were stratified by BCS and breed. In both experiments cattle were randomly allotted to receive either dinoprost (25 mg) or cloprostenol (500 μg). Estrus was detected 3 times per day for 72 h after PGF, and AI was conducted by the am/pm rule. At 72 h after PGF, nonresponders were timed artificially inseminated and received gonadotropin-releasing hormone. The AI pregnancy rates were similar (<i>P</i> > 0.05) between PGF treatments in Exp. 1 (51%) and Exp. 2 (46%). In Exp. 1, AN (52%), 1/4 to 3/8 BR (42%), and 1/2 BR (59%) cows had similar AI pregnancy rates, whereas 1/2 BR (59%) had a greater (<i>P</i> < 0.05) AI pregnancy rates compared with cows with ≥3/4 BR (41%). In Exp. 2, heifer breed had no effect on AI pregnancy rates. In conclusion, dinoprost and cloprostenol in a SSCT protocol yielded similar AI pregnancy rates in cows and 2-yr-old virgin heifers across all breed types; however, AI pregnancy rates were influenced by breed type in cows but not 2-yr-old virgin heifers.

Gonadotropin-releasing hormone increased pregnancy risk in suckled beef cows not detected in estrus and subjected to a split-time artificial insemination program.

We hypothesized that GnRH would increase pregnancy risk (PR) in a split-time AI program for cows in which estrus was not detected. A total of 1,236 suckled beef cows at 12 locations in 3 states (Colorado, Kansas, and North Dakota) were enrolled. Before applying the fixed-time AI program, BCS was assessed. Cows were treated on d -7 with a progesterone insert concurrent with 100 μg GnRH and on d 0 with 25 mg PGF plus removal of the insert. Estrus-detection patches were affixed to cows at insert removal. Estrus was defined to have occurred when an estrus-detection patch was >50% colored (activated). Cows in estrus by 65 h ( = 758; 61.3% of all cows) were randomly allocated to 2 treatments: 1) 100 μg GnRH and early + GnRH (E+G; = 373) or 2) AI only at 65 h (early - no GnRH [E-G]; = 385). The remaining cows were randomly allocated to 2 treatments: 1) 5(L+G; = 252) or 2) AI only at 84 h (late no GnRH [L-G]; = 226). Pregnancy was determined 35 d after AI via transrectal ultrasound. Pregnancy risk did not differ ( = 0.68) between E+G and E-G cows (61.9 vs. 60.4%, respectively). Conversely, for cows inseminated at 84 h, PR was greater ( = 0.01) in cows that received GnRH (L+G) compared with their herd mates not receiving GnRH (L- G; 41.7 vs. 30.8%, respectively). Of those cows not detected in estrus by 65 h, 42.1% were detected by 84 h, for a total expression of estrus by all cows of 77.6%. Administration of GnRH increased ( < 0.01) PR in cows not detected in estrus by 84 h (+GnRH = 33.4% [ = 146] vs. no GnRH = 15.0% [ = 128]) but had no effect in cows expressing estrus by 84 h (+GnRH = 65.3% [ = 103] vs. no GnRH = 61.7% [ = 97]). Neither estrus expression by 65 or 84 h nor PR was influenced by BCS, parity, or days postpartum at AI. Cows had greater PR when they had been detected in estrus before AI, and PR was improved by administration of GnRH at 65 h after insert removal in cows that were not detected in estrus and inseminated at 84 h.

Comparison of two timed artificial insemination system schemes to synchronize estrus and ovulation in Nellore cattle

The aim of this study was to evaluate the reproductive performance of 411 Nellore cows (198 nulliparous, 80 primiparous, and 133 multiparous) submitted to the 5dCO-Synch + P4 or 7dEB + P4 systems. The 5dCO-Synch + P4 system consisted of insertion of an intravaginal progesterone (P4) insert and 100 μg of GnRH (intramuscularly [i.m.]) on Day 0. On Day 5, the P4 insert was removed, and two doses of 25 mg of PGF2α (i.m.) were administered 6 hours apart. Cows not detected in estrus until 55 hours after insert removal received 100 μg of GnRH i.m. 17 hours later (i.e., 72 hours after P4 removal). The 7dEB + P4 system consisted of insertion of a P4 insert and 2 mg of estradiol benzoate (i.m.) on Day 0. On Day 7, the P4 insert was removed and 25 mg of PGF2α, 0.6 mg of estradiol cypionate, and 300 IU of eCG were administered i.m. In both systems, artificial insemination (AI) was performed according to estrus detection (i.e., cows detected in estrus until 55 hours after insert removal were inseminated at 55 hours and cows detected in estrus later or those not detected in estrus were inseminated at 72 hours). Estrus-detection risk was greater (P < 0.05) in 7dEB + P4 (80.4%) than 5dCO-Synch + P4 system (36.4%). Progesterone concentration 10 days after AI was greater (P < 0.05) in 7dEB + P4 than 5dCO-Synch + P4 system in primiparous and multiparous but did not differ between systems in nulliparous cows. Pregnancy per AI was greater (P < 0.05) in 7dEB + P4 (49.7%) than 5dCO-Synch + P4 (35.4%) system. Primiparous had lower estrus-detection risk (25.0%), ovulation risk (76.6%), and pregnancy per AI (28.7%) than multiparous or nulliparous cows. In conclusion, reproductive performance was reduced with the 5dCO-Synch + P4 in comparison with the 7dEB + P4 system in Nellore cows. Moreover, the reproductive traits observed for primiparous cows indicate that more attention is required when timed AI programs are started early after calving.

Qualitative and quantitative analysis of bacteria from vaginitis associated with intravaginal implants in ewes following estrus synchronization

ABSTRACT: This study evaluated the presence of vaginitis and the bacterial load associated with different intravaginal implants in ewes. Twenty-four Dorper and crossbred ewes were allocated into three groups and received intravaginal implant containing 0.3g progesterone (CIDR(r)), 60mg MAP or sponges without progesterone (CONTROL) for six days. Then, CIDR and MAP treated-ewes received 12.5mg dinoprost and 300IU eCG. Vaginal mucus samples were collected at four times: before device insertion, at the day of its removal, 24 and 48 hours after. The samples were cultured and the colonies were counted (CFU/mL) and identified. The results obtained from the counting of CFU mL-1 were submitted to Kruskal-Wallis H test, with P&lt;0.05 being considered significant. Before device insertion, 68.2% of the samples yielded Staphylococcus spp. and 60.0% of them were Staphylococcus aureus. After implant removal, 100% of ewes had clinical signs of vaginitis. However, the level of local infection in the CONTROL-ewes was lower (P&gt;0.05) in comparison with MAP and CIDR-treated ewes. During the occurrence of vaginitis, the predominant isolates belonged to the coliform group, mainly Escherichia coli (72.7%). Such infection was not determined by the members of the vaginal microbiota that were present before implant insertion and normal microbiota was restored between 24 to 48 hours after insert removal.

Fertility after two doses of PGF2α concurrently or at 6-hour interval on the day of CIDR removal in 5-day CO-Synch progesterone-based synchronization protocols in beef heifers

Timed artificial insemination protocols in beef cattle are designed to synchronize ovulation in a greater proportion of females while simultaneously achieving acceptable pregnancy rates and a concise calving season. Protocols achieving such goals reduce time and labor associated with estrus detection and make advanced reproductive technologies implementable for beef producers. The objective of the study was to determine the effect of three different PGF2α (PGF) dosage schemes on artificial insemination (AI) pregnancy rates in beef heifers. We hypothesized that two doses of PGF administered concurrently at the time of controlled internal drug release (CIDR) removal would attain similar pregnancy rates compared with two doses given 6-hours apart—one at CIDR removal and the next 6 hours later in the 5-day CO-Synch progesterone-based synchronization protocol. Angus heifers (n = 875) at six locations in Washington, Idaho, and Oregon states were included in this study. Heifers within locations were assigned a body condition score (BCS). All heifers received a CIDR (1.38 g of progesterone) and 100 μg IM of GnRH on Day 0. The CIDRs were removed on Day 5, heifers were randomly allocated to one of three protocol groups: 1PGF (n = 291), received 25 mg IM of dinoprost (PGF); 2CO-PGF (n = 291), received 50 mg IM of dinoprost at CIDR removal, 2PGF (n = 293), received 25 mg IM of dinoprost at CIDR removal, and an additional 25 mg IM of dinoprost 6 hours later. Each heifer was given GnRH (100 μg, IM) and artificially inseminated at 56 hours after CIDR removal. Heifers were examined for pregnancy status between 50 and 70 days after AI to determine time of conception. A mixed-model procedure (PROC GLIMMIX of SAS) was used to evaluate the effect of treatments (1PGF, 2CO-PGF, and 2PGF) on AI pregnancy rates. Models included were treatments, BCS categories (≤5 and >5), and treatment by BCS category interaction. Location (state), handling facilities, handlers, inseminators, and AI sires were included as a random effect in the model. The 2PGF group had greater AI pregnancy rate of 63.6% (185/291), compared with the 2CO-PGF group at 51.9% (151/291) and 1PGF group at 54.9% (161/293; P < 0.001). An AI pregnancy rate of 50% (104/208) was observed for heifers with BCS less than or equal to 5 versus 58.9% (393/667) for heifers with BCS greater than 5 (P < 0.05). Location did not influence the AI pregnancy rate (P > 0.1). In conclusion, beef heifers received two 25-mg doses of PGF at 6-hour interval on Day 5 at CIDR insert removal in a 5-day CO-Synch + CIDR synchronization protocols achieved greater pregnancy compared with heifers received 50 mg of PGF concurrently at CIDR removal.

Synchronized ovulation for first insemination improves reproductive performance and reduces cost per pregnancy in dairy heifers

The objectives were to evaluate the effects of synchronizing estrus and ovulation to implement a timed artificial insemination (AI) at first insemination on reproductive performance and cost per pregnancy in dairy heifers. Six hundred eleven Holsteins heifers at approximately 400 d of age from 3 farms were enrolled in the study. Six days before moving to the breeding pens, heifers were allocated randomly to AI after detected estrus from study d 0 to 84 (CON, n=306), or to timed AI for first AI followed by detected estrus for the remainder of the 84-d study (TAI, n=305). Heifers receiving TAI were enrolled in the 5-d timed AI protocol on study d −6 (d −6, GnRH and a progesterone insert; d −1, PGF2α and insert removal; d 0, PGF2α; d 2, GnRH + AI), and they were allowed to be bred the day before scheduled timed AI if detected in estrus. Starting on study d 0, estrus was detected daily. Heifers in estrus were inseminated on the same morning as detected estrus. Control heifers not inseminated by study d 7 received PGF2α and this treatment was repeated every 2 wk until AI. The study lasted 84 d to allow a period of breeding equivalent to four 21-d estrous cycles. A herd budget accounting for inputs for both treatments was created to determine the cost per pregnancy. Sensitivity analysis compared economic differences between the 2 treatments under different input scenarios when detection of estrus after the first AI varied from 50 to 80%. Interval to first AI was 8 d shorter for TAI than for CON. Pregnancy at first AI did not differ between treatments (CON=58.3 vs. TAI=62.8%). In contrast, TAI increased pregnancy per AI (P/AI) compared with CON in heifers inseminated with sex-sorted semen (CON=31.6 vs. TAI=54.8%). The 21-d cycle insemination rate was greater for TAI (91.4%) than for CON (82.4%), even when evaluated after the first 21 d in the study (CON=68.2 vs. TAI=77.1%). The increased insemination rate improved the 21-d cycle pregnancy rate from 47.9% in CON to 57.2% in TAI heifers. In fact, the hazard of pregnancy was 60% greater for TAI than CON. The increased pregnancy rate in TAI reduced the median days to pregnancy by 12 d (CON=2.0 vs. TAI=14.0) and increased the proportion of pregnant heifers by 6.3 percentage points by study d 84 (CON=85.2 vs. TAI=91.5%). The cost per pregnancy was $17.00 less for TAI than CON. The sensitivity analysis indicated that TAI was economically more advantageous to produce a pregnancy compared with CON. Only when insemination rate after the first 21 d of breeding was very high and P/AI was relatively low did the cost per pregnancy become similar for the 2 treatments. Collectively, inseminating all heifers within 2 d of breeding with the 5-d timed AI protocol maintains P/AI, improves pregnancy rate, and reduces cost per pregnancy compared with insemination after detected estrus.