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نتیجه جستجو - Pregnancy

تعداد مقالات یافته شده: 38
ردیف عنوان نوع
1 اثر پره اکلامپسی و شدت آن بر سطح سرم NGAL مادری و KIM-1 طی بارداری و بعد زایمان
سال انتشار: 2021 - تعداد صفحات فایل pdf انگلیسی: 6 - تعداد صفحات فایل doc فارسی: 17
هدف: هدف از این آزمایش،ارزیابی اثرات پره اکلامپسی و شدت آن بر سطح سرم مادری لیپوکالین مرتبط با ژلاتیناز نوتروفیل ژلاتیناز (NGAL) و (KIM 1) در دوران بارداری و دوره پس از بارداری می باشد.
طراحی مطالعه: ابتدا شرکت کنندگان باردار (156 نفر) به سه گروه کنترل، خفیف،و پره اکلامپسی شدید تقسیم بندی شدند. در مرحله دوم زنان در دوره پس اززایمان (368 نفر) به سه گروه با توجه به سابقه دوران حاملگی، به عنوان کنترل سالم، پره اکلامپسی خفیف و شدید تقسیم بندی شدند. این زنان از طریق سیستم داده های بیمارستان شناسایی و با آنها تماس گرفته شد تا در این تحقیق شرکت کنند.
دستاورد: مطالعه ما شامل 147 بیمار بود که 77 نفر از آنها باردار و 70 نفر از آنها پس از بارداری پس از اعمال معیارهای خروج بودند. از نظر سطح NGAL سرم مادر ،افزایش قابل توجهی در گروه پره اکلامپسی شدید در مقایسه با گروه خفیف پره اکلامپسی و گروه های باردار طبیعی وجود دارد(p < 0.001). در دوران بعد زایمان، سطح سرم NGAL مادری در گروه پره اکلامپسی شدید نسبت به افراد با پره اکلامپسی خفیف و گروه کنترل فشار خون بالا به طور قابل توجهی بالاتر بود(p < 0.001). سطح سرم KIM 1 مادری در گروه پره اکلامپسی شدید و خفیف به طور قابل توجهی نسبت به گروه با کنترل فشار خون بالا، بالاتر ارزیابی شده است (p = 0.004). در دوره بعد زایمان، سطح سرم KIM-1 مادری در تمام گروه های بارداری مشابه دیده شد(p = 0.792).
نتایج: دستاوردهای ما نشان می دهد که هرچه شدت پره اکلامپسی افزایش یابد، آسیب کلیه، همانطور که با استفاده از سطح NGAL ارزیابی می شود، برای مدت زمان طولانی حتی در دوران پس از بارداری نیز ادامه دارد. © 2020 Elsevier B.V تمام حقوق محفوظ است .
کلمات کلیدی: پره اکلامپسی | آسیب کلیوی | نوتروفیل ژلاتیناز وابسته به لیپوکالین | NGAL | مولکول | آسیب کلیوی -1 | KIM-1
مقاله ترجمه شده
2 Women with a substance use disorder: Treatment completion, pregnancy, and compulsory treatment
زنان مبتلا به اختلال مصرف مواد: پایان درمان ، بارداری و درمان اجباری-2020
Over the last several decades, research regarding substance use treatment programs has focused on the unique and differential outcomes of male and female illicit substance users. Research less frequently examines the unique individual and contextual factors that may influence treatment outcomes. One such population that merits special consideration is pregnant women, as substance use within this population has deleterious effects for both the women and their unborn children. The current study employs propensity score matching to determine if pregnancy and referral source to treatment affect treatment program outcomes. Findings suggest that pregnant women, compared to similarly situated nonpregnant women, are significantly less likely to complete substance use treatment; however, pregnant women who were referred to treatment by the criminal justice system were significantly more likely to complete treatment than those who entered treatment by other referral sources.
Keywords: Substance abuse treatment | Illicit drug use | Pregnant | Treatment episode data
مقاله انگلیسی
3 Postpartum health disorders in lactating dairy cows and its associations with reproductive responses and pregnancy status after first timed-AI
اختلالات بهداشتی پس از زایمان در گاوهای شیری شیرده و ارتباط آن با پاسخ های تولید مثل و وضعیت بارداری پس از اولین زمانبندی هوش مصنوعی-2020
The objective was to evaluate the association between postpartum health disorders, reproductive responses and pregnancy status in lactating multiparous cyclic Holstein cows. Cows were retrospectively categorized as healthy (n ¼ 70) or sick (n ¼ 60) based on postpartum health records and serum metabolites. Sick cows were further categorized as having metabolic (MET; n ¼ 35), infectious (INF; n ¼ 15), or both diseases (MET/INF; n ¼ 10). Blood samples were collected on d 7 and 14 after calving to determine serum concentrations non-esterified fatty acids (NEFA), b-hydroxybutyrate (BHB) and aspartate aminotransferase (AST), on d 0 (TAI), 8, 16, 18 and 20 after TAI to determine concentrations of progesterone (P4; d 0, 8, 16, 18 and 20) and prostaglandin F metabolite (PGFM; d 16, 18 and 20) and interferonstimulated gene-15 (ISG15; d 16) relative mRNA expression. Cyclicity was determined by transrectal ultrasonography 30 d postpartum and cows were subjected to a GnRH-based TAI protocol (to classify cows bearing a visible CL as cyclic). Prediction of pregnancy status on d 16 after TAI was determined by ISG15 mRNA gene expression relative to b actin and following, pregnancy was diagnosed by transrectal ultrasonography at 32 and 60 d after TAI. An interaction (P ¼ 0.04) between occurrence of disease and pregnancy status was detected for the expression of ISG15 in blood, with healthy pregnant healthy cows having the greatest relative expression of ISG15. Postpartum health disorders were associated with reduced concentration (P < 0.05) of serum P4 post TAI. However, serum P4 concentrations at TAI were greater (P ¼ 0.01) in sick cows (0.65 ± 0.09, 0.86 ± 0.13 and 0.75 ± 0.10 ng/mL for MET, INF and MET/INF cows, respectively) compared with that in healthy cows (0.24 ± 0.10 ng/mL). Serum concentrations of PGFM after TAI was reduced in healthy cows, regardless of pregnancy status. Pregnancy status on d 16 after TAI predicted by ISG15 mRNA expression and P/AI on d 32 and 60 after TAI based on ultrasonography, were negatively affected (P < 0.05) by occurrence of health disorders. Similarly, pregnancy loss from d 16 to 32 and d 16 to 60 after TAI was greater (P < 0.05) in sick cows compared to that in healthy cows. However, neither P/AI nor pregnancy loss were associated to the category of postpartum health disorder. Cows affected by postpartum health disorders had overall reduced P4 and greater PGFM serum concentrations after TAI, which were associated with reduced pregnancy success and enhanced pregnancy loss. Collectively, our findings support the hypothesis of a carryover effect of disease on reproductive responses, embryo survival and maintenance of pregnancy in lactating dairy cows independent of the category of postpartum health disorder.
Keywords: Fertility | Maintenance of pregnancy | Embryonic mortality | ISG15
مقاله انگلیسی
4 Comparison of the effects of two shortened timed-AI protocols on pregnancy per AI in beef cattle
مقایسه اثرات دو پروتکل کوتاه شده با هوش مصنوعی به هنگام روی بارداری در هوش مصنوعی در گاوهای گوشتی-2020
The objective was to compare pregnancy per AI (P/AI) between two shortened timed-AI (TAI) protocols in beef cattle. This study also determined whether administration of eCG in heifers and timing of AI in cows would affect P/AI. Cattle were submitted at random to either a modified 5-d Co-synch protocol (Day 0 ¼ progesterone releasing device (CIDR); Day 5 ¼ CIDR removal and 500 mg of cloprostenol (PGF); Day 8 ¼ 100 mg GnRH concurrent with AI) or J-synch protocol (Day 0 ¼ CIDR insertion and 2mg of estradiol benzoate i.m.; Day 6 ¼ CIDR removal and 500 mg PGF; Day 9 ¼100 mg GnRH concurrent with AI). In Experiment 1, 1135 heifers (13e15 mo of age) received an estrus detection patch (Estrotect™) on Day 5 and 579 were selected at random to receive 300 IU of equine chorionic gonadotropin (eCG) at the time of CIDR removal. Patches were scored from 0 to 3 based on color change between initial application and AI; 0 ¼ unchanged, 1¼ 50% change, 2 ¼ > 50% change, 3 ¼ missing. Estrus was defined to have occurred when the patch was scored 2 or 3. In Experiment 2, 399 cyclic, non-lactating beef cows from 1 location were submitted to either the modified 5-d Co-synch or J-synch protocol and within each protocol cows were TAI at either 66 ±1 (n¼ 199) or 72 ±1 h (n ¼ 200) following CIDR removal. Transrectal ultrasonography was used in both experiments to determine presence of a corpus luteum (CL) on Day 0, and to diagnose pregnancy 35 d after TAI. In Experiment 1, eCG increased estrus rate only in heifers without a CL on day 0 that were submitted to the modified 5-d Co-synch protocol (41.9 vs. 69.6%). Heifers submitted to the J-synch protocol had greater (P ¼ 0.03) P/AI compared with those in the modified 5-d Co-synch (48.7 vs. 41.1%) and heifers that expressed estrus before AI had increased (P < 0.0001) P/AI compared to those that did not (53.6 vs. 36.5%). Administration of eCG and presence of a CL tended to affect P/AI (P ¼ 0.13). In Experiment 2, cows submitted to the J-synch protocol tended (P ¼ 0.07) to have greater P/AI compared to those in the modified 5-d Co-synch (74.1 vs. 66.5%). There was no association between P/AI and timing of AI. In summary, the J-synch protocol resulted in greater P/AI than the modified 5-day Co-synch protocol in heifers and cows. Administration of eCG increased estrus rate in heifers without a CL at the start of the protocol and tended to improve P/AI in all heifers. Timing of AI (66 vs. 72 h) had no effect on P/AI in cows subjected to either TAI protocol.
Keywords: 5-d Co-Synch | J-synch | Pregnancy per AI | Cyclicity | Estrus detection | eCG
مقاله انگلیسی
5 Pregnancy rates to fixed-time AI in Bos indicus-influenced beef cows using PGF2a with (Bee Synch I) or without (Bee Synch II) GnRH at the onset of the 5-day CO-Synch þ CIDR protocol
نرخ حاملگی به هوش مصنوعی با زمان ثابت در گاوهای گوشتی تحت تأثیر علامت Bos با استفاده از PGF2a با (Bee Synch I) یا بدون (Bee Synch II) GnRH در آغاز پروتکل 5 روزه CO-Synch þ CIDR-2020
Objectives were to 1) characterize fixed-time AI (FTAI) pregnancy rates using the 5-Day CO-Synch þ CIDR protocol in mature, suckled Bos indicus-influenced beef cows, 2) compare FTAI pregnancy rates in the latter to a modified version (5-Day Bee Synch þ CIDR; Bee Synch I) that included treatment with prostaglandin F2a (PGF2a) at CIDR insertion on Day 0, and 3) test the hypothesis that elimination of both GnRH-1 at the onset of synchronization and the double dose of PGF on Day 5 (Bee Synch II) would not reduce FTAI pregnancy rates compared to Bee Synch I. For Experiment 1-trial 1, Brahman x Hereford (F-1) cows (n ¼ 168) at least 40 d postpartum (PP; r ¼ 40e92 d) at the time of CIDR insertion were administered the 5-Day CO-Synch þ CIDR protocol with FTAI at 72 h after CIDR removal. Pregnancy rates to FTAI averaged 34.9 ± 1.9%. In Experiment 1-trial 2, fall- and spring-breeding Brahman x Hereford (F-1) beef cows (n ¼ 269) were stratified by days PP and assigned randomly to receive either the 5-Day COSynch þ CIDR (n ¼ 136) or Bee Synch I (n ¼ 133) protocol, with FTAI at 66 h after CIDR removal. Pregnancy rate to FTAI was greater (P < 0.05) in Bee Synch I (52.6 ± 0.9%) than in the 5-Day COSynch þ CIDR procedure (40.4 ± 5.7%). For Experiment 2, 422 mature Braford, Brangus, Nelore x Brahman, and Brahman crossbred cows (Bos indicus proportion unknown) at 4 locations were treated with Bee Synch I, with FTAI at 66 h. Overall FTAI pregnancy rate averaged 51.7 ± 2.1%. Finally, from 2013 through spring 2018, we used a switchback design using fall- and spring-breeding herds to compare Bee Synch I (402 observations) to Bee Synch II (393 observations). Overall frequency of detected estrus at 66 h using ESTROTECT™ breeding indicator patches was 57.2 ± 2.4%, conception rates of those detected in estrus was 64.4 ± 3.5%, and FTAI pregnancy rates averaged 52.3 ± 2.4%, none of which differed between treatments. Moreover, pregnancy rates to FTAI in both treatments did not differ in cows synchronized between 40 and 80 d PP but increased after 80 d PP (P < 0.05). Bee Synch II, which eliminates GnRH-1 and the double dose of PGF2a on Day 5, results in FTAI pregnancy rates essentially identical to Bee Synch I but reduces synchronization costs and avoids the need for off-label (double dose PGF2a) drug use.
Keywords: 5-Day CO-Synch þ CIDR | Prostaglandin F2a | GnRH | Bos indicus | Bee synch
مقاله انگلیسی
6 Progesterone-based timed AI protocols for Bos indicus cattle II: Reproductive outcomes of either EB or GnRH-type protocol, using or not GnRH at AI
پروتکل های هوش مصنوعی به موقع مبتنی بر پروژسترون برای Bos indicus II: نتایج تولید مثل پروتکل نوع EB یا GnRH ، استفاده یا عدم استفاده از GnRH در هوش مصنوعی-2020
The aim of these experiments was to study ovarian dynamics and fertility of Bos indicus beef cattle submitted to 7-d progesterone (P4)-based fixed-time AI (FTAI) protocols using different hormonal treatments. In Exp. 1, 2 yr old Nelore heifers (n ¼ 973) were randomly assigned to one of four treatments: EB-0 (estradiol benzoate, EB on D0 and no GnRH at AI), EB-G (EB on D0 and GnRH at AI), G-0 (GnRH on D0 and no GnRH at AI), or G-G (GnRH on D0 and at AI). On D0, heifers received an intravaginal P4 implant (0.5 g) for 7 d and EB (1.5 mg) or GnRH (16.8 mg). On D7, the P4 implant was withdrawn and heifers received cloprostenol (PGF; 0.5 mg) and estradiol cypionate (EC, 0.5 mg). Heifers in G groups also received PGF and eCG (200 IU) on D6, whereas EB heifers received eCG on D7. At FTAI on D9, only EB-G and G-G groups received GnRH (8.4 mg). In Exp. 2, Nelore cows (n ¼ 804) received the same treatments (EB-0, EB-G, G-0, or G-G) using a 1.0 g P4 implant, 2.0 mg EB, and 300 IU eCG. Effects were considered significant when P  0.05. After treatment on D0, G had more ovulations than EB in heifers (60.3 [287/ 476] vs. 12.7% [63/497]) and cows (73.7 [83/112] vs. 24.4% [28/113]). Luteolysis after D0 was greater in EB than G in heifers (39.2 [159/406] vs. 20.0% [77/385]) and cows (25.5 [14/55] vs. 1.6% [1/64]). Heifers in G had larger follicles (mm) than EB on D7 (10.3 ± 0.2 vs. 9.2 ± 0.2) and at AI (11.9 ± 0.2 vs. 11.3 ± 0.2). Cows had larger follicles in G than EB on D7 (11.0 ± 0.3 vs. 9.9 ± 0.3) but not at AI. More estrus was observed in G than EB for heifers (80.3 [382/476] vs. 69.6% [346/497]) and cows (67.6 [270/400] vs. 56.2% [227/404]). There was no interaction between D0 and D9 treatments on pregnancy per AI (P/AI) in heifers (EB-0: 56.7 [139/245], EB-G: 53.6 [135/252], G-0: 52.6 [127/241], and G-G: 57.5% [135/235]). However, cows from EBG had greater P/AI than EB-0 (69.5 [142/204] vs. 60.2% [120/200]), whereas P/AI for G-0 (62.7% [127/203]) was similar to G-G (60.9% [120/197]). In heifers, there was no interaction of GnRH at AI with estrus, however, cows that did not display estrus had greater P/AI if they received GnRH at AI (GnRH ¼ 59.1 [91/ 154] vs. No GnRH ¼ 48.2% [78/162]). Thus, protocols initiated with EB or GnRH for Bos indicus heifers and cows had differing ovarian dynamics but similar overall fertility, enabling their use in reproductive management programs. Treatment with GnRH at time of AI increased fertility in some instances in Bos indicus cows but not in heifers.
Keywords: Beef cattle | Estrus | Fertility | GnRH | Ovulation
مقاله انگلیسی
7 Oocyte and embryo evaluation by AI and multi-spectral autofluorescence imaging: Livestock embryology needs to catch-up to clinical practice
ارزیابی تخمک و جنین توسط هوش مصنوعی و تصویربرداری خودکار فلورسانس چند طیفی: جنین شناسی دام باید به مراحل بالینی برسد-2020
A highly accurate ‘non-invasive quantitative embryo assessment for pregnancy’ (NQEAP) technique that determines embryo quality has been an elusive goal. If developed, NQEAP would transform the selection of embryos from both Multiple Ovulation and Embryo Transfer (MOET), and even more so, in vitro produced (IVP) embryos for livestock breeding. The area where this concept is already having impact is in the field of clinical embryology, where great strides have been taken in the application of morphokinetics and artificial intelligence (AI); while both are already in practice, rigorous and robust evidence of efficacy is still required. Even the translation of advances in the qualitative scoring of human IVF embryos have yet to be translated to the livestock IVP industry, which remains dependent on the MOET-standardised 3- point scoring system. Furthermore, there are new ways to interrogate the biochemistry of individual embryonic cells by using new, light-based methodologies, such as FLIM and hyperspectral microscopy. Combinations of these technologies, in particular combining new imaging systems with AI, will lead to very accurate NQEAP predictive tools, improving embryo selection and recipient pregnancy success.
Keywords: Embryo selection | Machine learning | Pregnancy establishment | Embryo metabolism | Morphokinetics
مقاله انگلیسی
8 Early resynchronization of non-pregnant beef cows based in corpus luteum blood flow evaluation 21 days after Timed-AI
هماهنگی مجدد اولیه گاوهای گوشتی غیر باردار مبتنی بر ارزیابی جریان خون جسم زرد 21 روز پس از زمانبندی هوش مصنوعی -2020
The study aimed to verify whether a hormone protocol started at Day 13 (D13) after Timed Artificial Insemination (TAI) influences the conception rate. Nelore cows (primiparous and multiparous) from two commercial beef farms (n ¼ 1,431) were first TAI (D0). Timed AI was performed in lots (TAI Lots) ranging from 187 to 346 cows. On D13, regarding the TAI lot, cows were assigned for either receiving (Resynch group, n ¼ 1,002) or not (Control group, a subset of approximately 30%, n ¼ 429) another hormone protocol for resynchronization. The same hormone protocol was used for the first TAI and for the resynchronization, except for 1 mg instead of 2 mg of estradiol benzoate (EB) at the begging of the protocol. Eight days later (D21), the Resynch group was checked for corpus luteum blood flow by color Doppler ultrasonography, and in those detected as non-pregnant, the protocol was completed and a 2nd TAI was performed at D23. Pregnancy diagnosis was later (D30) performed by B-mode ultrasonography in the control group and confirmed in the presumptive pregnant cows from the 1st TAI of the Resynch group. The remaining cows were checked for pregnancy 30 days after the 2nd TAI (experimental Day 53). The statistical model to explain conception rate considered the effects of Group (Control or Resynch), Farm, Parity (primiparous or multiparous), Sire, Technician (who perform AI), TAI Lot and pertinent interactions (Group*Parity, Group*Farm and Group*TAI Lot). The statistical analyses of the model were performed using the Proc Glimmix (SAS virtual University Edition). The conception rate for the 1st TAI was similar (P > 0.4) between Control (50.3%, 216/429) and Resynch group (52.6%, 527/1002). The positive predictive diagnostic on D21 showed high relation with PD30 (90.7%, 527/581). In Resynch group, non-pregnant cows (n ¼ 421, 1002 minus 581) were re-inseminated. The conception rate of the 2nd TAI (42.8%, 180/421) was affected (P < 0.002) by side effects of the Farm (48.5 vs. 33.1%) and Parity (51.2 vs. 40.3%, for multiparous vs. primiparous, p < 0.001). Nevertheless, after the 2 TAIs of the Resynch group, the cumulative conception rate was 70.5% (707/1002). In conclusion, the early resynchronization of cows with a low (1 mg) EB dose and progesterone device at D13 after TAI can be used as a strategy to reduce conception interval in beef cattle, and thus to increase the number of pregnant cows from artificial insemination after the breeding season.
Keywords: Color Doppler | Pregnancy diagnosis | Re-insemination
مقاله انگلیسی
9 Progesterone-based timed AI protocols for Bos indicus cattle III: Comparison of protocol lengths
پروتکل های هوش مصنوعی بهنگام پروژسترون برای Bos indicus III: مقایسه طول پروتکل-2020
This study aimed to validate a 7 d progesterone (P4)-based fixed-time AI (FTAI) protocol for Bos indicus cattle by comparing to 8 and 9 d-type protocols. The first study compared 7 vs. 8 d protocols in Nelore heifers (Exp. 1.1; n ¼ 742) and cows (Exp. 1.2; n ¼ 2488), and the second study compared 7 vs. 9 d protocols in cows (Exp. 2; n ¼ 1343). On experimental Day 10 and Day 11 the 8 and 9 d groups received an intravaginal P4 implant, 2.0 mg estradiol benzoate (EB) and 0.5 mg cloprostenol sodium (PGF). On Day 9 the 7 d group received the same treatments (P4, EB, and PGF). Then, on Day 2 all groups had the P4 implants removed, and PGF, 0.6 mg estradiol cypionate, and 300 IU equine chorionic gonadotropin (eCG) was administered. Fixed-time AI was performed 48 h later (Day 0) and 8.4 mg buserelin acetate (GnRH) was administered to 7d-G, 8d-G and 9d-G groups, whereas 7d-0, 8d-0 and 9d- 0 groups did not receive GnRH at AI. Estrus was detected using tail-chalk between Day 2 and Day 0. Pregnancy per AI (P/AI) was evaluated by ultrasound 30 d after AI. Effects were considered significant when P  0.05, whereas a tendency was designated when P  0.10 and P > 0.05. In heifers (Exp. 1.1), incidence of estrus was similar regardless of protocol length (7 or 8 d). There was no independent treatment effect on P/AI or interaction between protocol length and GnRH at AI for P/AI (7d-0: 46.9, 7d- G: 51.4, 8d-0: 47.7, and 8d-G: 43.6%). Heifers in estrus had greater P/AI, and GnRH had no additional effect. More cows (Exp. 1.2) from the 8 d protocol were in estrus than cows submitted to the 7 d protocol. Additionally, despite no interaction between protocol length and GnRH on P/AI (7d-0: 55.9, 7d-G: 60.9, 8d-0: 56.2, and 8d-G: 60.8%), GnRH at AI increased P/AI. There was no interaction between estrus and GnRH, but cows displaying estrus had greater P/AI. Cows not expressing estrus tended (P ¼ 0.06) to have greater P/AI when receiving GnRH. In Exp. 2, more 9 d cows were in estrus than 7 d cows. Protocol length did not affect P/AI but tended (P ¼ 0.08) to interact with GnRH (7d-G had greater P/AI [57.9%] than 7d- 0 [47.6%], but 9d-0 [54.6%] and 9d-G [55.4%] were not different from other groups). Moreover, GnRH increased P/AI only for the 7 d protocol. No interaction between estrus and GnRH was detected but estrus improved P/AI, and GnRH tended (P ¼ 0.09) to improve P/AI of cows in estrus. In conclusion, despite longer protocols being more conducive to expression of estrus, there were no detectable effects of protocol length on P/AI. In addition, GnRH at FTAI may improve fertility in cows, particularly when cows are treated with shorter protocols.
Keywords: Beef cattle | Estrus | Fertility | Nelore | Synchronization
مقاله انگلیسی
10 Prostaglandin F2a influences pre-ovulatory follicle characteristics and pregnancy per AI in anovular dairy cows
پروستاگلاندین F2a بر خصوصیات فولیکول قبل از تخمک گذاری و بارداری در هوش مصنوعی در گاوهای شیری بی قاعده تأثیر می گذارد-2020
Objectives were to determine the effects of a dose of PGF2a administered 2 days before timed artificial insemination (AI) on LH pulsatility, characteristics of the pre-ovulatory follicle, and pregnancy per artificial insemination (P/AI) in anovular dairy cows, particularly in cows not subjected to hyperthermia. In experiment 1, 2,011 lactating Holstein cows had ovaries scanned by ultrasound to determine corpus luteum (CL) presence and only those without a CL in two consecutive exams were enrolled (n ¼ 437). Cows had the estrous cycle synchronized with an estradiol-progesterone based protocol starting on experiment Day 11 and timed AI on Day 0. Cows were assigned randomly to receive a single dose of 25 mg of PGF2a as dinoprost on Day 4 (1PGF, n ¼ 222) or two doses of 25 mg each of PGF2a, one on Day 4 and one on Day 2 (2PGF, n ¼ 215). Rectal temperatures were evaluated on the day of AI and 7 days later and cows were classified as being normothermic (<39.1 C) or hyperthermic (39.1 C). Ovulatory responses and P/AI were determined. In experiment 2, cows with regressed CL were exposed to low concentrations of progesterone and then randomly assigned to the same estrous synchronization protocol and treatments, 1PGF (n ¼ 28) and 2PGF (n ¼ 28). Blood was sampled and analyzed for concentrations of progesterone, and for concentrations of LH and 13,14-dihydro-15-keto-PGF2a metabolite (PGFM) every 15 min starting 1 h before to 6 h after treatments and then every 2 h from 12 to 59 h after treatments. The pre-ovulatory follicle was aspirated 44 h after treatments and concentrations of estradiol quantified. In experiment 1, treatment of anovular cows with a second dose of PGF2a increased P/AI in normothermic cows (19.8 [18/91] vs. 38.8% [31/80]), but not in hyperthermic cows. Synchronization was not affected by treatment, but it was greater for normothermic than hyperthermic cows (87.1 [149/171] vs. 77.8% [207/266]). When only synchronized cows were evaluated, the same responses were observed; treatment with 2PGF increased P/AI compared with 1PGF in normothermic cows (23.1 [18/78] vs. 43.7% [31/71]), but not in hyperthermic cows. In experiment 2, administration of 25 mg of dinoprost in 2PGF resulted in concentrations of PGFM 26-fold greater than 1PGF in the first 6 h after treatment (48 vs. 1,242 pg/mL). Cows receiving 2PGF had smaller basal LH concentration (0.57 vs. 0.46 ng/mL) and less frequent LH pulses (4.5 vs. 3.9 pulses/6 h), but duration of the LH surge was longer for 2PGF than 1PGF (13.1 vs. 15.5 h). Treatment with 2PGF increased the diameter and volume of the pre-ovulatory follicle, and concentration of estradiol (115 vs. 262 ng/mL) and total follicular estradiol content (124 vs. 505 ng) compared with 1PGF. Collectively, these results suggest that PGF2a has a role in fertility of anovular cows that is unrelated to its luteolytic effect.
Keywords: Anovular | Follicle | Dairy cow | Prostaglandin
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