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Copyright of Arquivo Brasileiro de Medicina Veterinaria e Zootecnia is the property of Universidade Federal de Minas Gerais, Escola de Veterinaria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recent data reveal that approximately 80% of bovine embryos produced in vitroworldwide are from (Brazil J. H. M. Viana, personal communication). Adoption of this biotechnology by Brazilian producers might be attributed to particularities of the Bos indicussubspecies. Zebu breeds provide 2 to 3 times more viable oocytes than Bos taurusbreeds per ovum pickup (OPU) session. This work aimed to evaluate the quality of cumulus–oocyte complexes (COC) retrieved from Gir breed cows (B. indicus) by OPU with a synchronized follicular wave and subjected to an in vitroembryo production (IVP) technique. All COC were obtained by OPU of 14 Gir cows performed every 14 days. There were 4 OPU sessions, preceded by synchronization of the follicular waves. Wave synchronization was achieved by an injection of 2mg of oestradiol benzoate followed by the insertion of a norgestomet implant that stayed in place for 5 days. On Day 5, follicles of 2 to 8mm were aspirated. The oocytes recovered were distributed according to classification: Group 1, with ≥3 cumulus cell layers and homogeneous or slightly heterogeneous cytoplasm (n=314); and Group 2, ≤2 cumulus cells layers and slightly or coarsely granulated cytoplasm (n=236). Oocytes from both groups were followed to in vitromaturation–IVF–fertilization–in vitroculture. Two (Day 2) and 8 (Day 8) days after the beginning of fertilization, the cleavage and blastocyst rates were measured, respectively. The statistical analyses were performed using a chi-square test (P<0.05). The mean cleavage rates observed were 72.93 and 69.07% (not significant), whereas the mean blastocyst rates were 37.90 and 17.80%, and were significantly different for Groups 1 and 2, respectively. The results suggest that the morphology of oocytes (number of cumulus cell layers and cytoplasm homogeneity) is a strong indicator of the in vitrodevelopmental capacity of oocytes recovered from Gir cows with synchronized follicular waves, although we did not observe compromised cleavage rates. Financial support was provided by Fapesp/Fapemig/CNPq/Embrapa. Epamig/Faz. Calciolândia/Nutricell–Nutrientes Celulares is acknowledged. [ABSTRACT FROM AUTHOR]

The effects of different dietary energy levels [100 and 170% for maintenance (M) and high energy (1.7M), respectively] on metabolic, endocrine, and reproductive parameters were evaluated in nonlactating Bos indicus (Gir; n = 14) and Bos taurus (Holstein; n = 14) cows submitted to ultrasound-guided ovum pick-up followed by in vitro embryo production. The oocyte donor cows were housed in a tiestall system and fed twice daily (0800 and 1600 h). Twenty-one days before the beginning of the experiment, the animals were fed with a maintenance diet for adaptation followed by the experimental diets (M and 1.7M), and each cow underwent 9 ovum pick-up procedures 14 d apart. The recovered oocytes were cultured in vitro for 7 d. We measured glucose and insulin concentrations and performed glucose tolerance tests and the relative quantification of transcripts (PRDX1, HSP70.1, GLUT1, GLUT5, IGF1R, and IGF2R) from the oocytes recovered at the end of the experimental period. No interactions were observed between the effects of genetic groups and dietary energy level on the qualitative (viable oocytes, quality grade, and oocyte quality index) and quantitative (oocytes recovered) oocyte variables. There were no effects of dietary energy level on the qualitative and quantitative oocyte variables. However, Bos indicus cows had greater numbers of recovered structures, viable oocytes, and A and B oocyte grades as well as better oocyte quality index scores and lower DNA fragmentation rates compared with Bos taurus donors. In vitro embryo production (cleavage and blastocyst rates and number of embryos) was similar between diets, but the 1.7M diet reduced in vitro embryo production in Bos indicus cows after 60 d of treatment. Moreover, Bos indicus cows on the 1.7M diet showed lower transcript abundance for the HSP70.1, GLUT1, IGF1R, and IGF2R genes. All cows fed 1.7M diets had greater glucose and insulin concentrations and greater insulin resistance according to the glucose tolerance test. In conclusion, increasing dietary energy did not interfere with oocyte numbers and quality, but the 1.7M diet reduced in vitro embryo production in Bos indicus cows after 60 d of treatment. Finally, Bos indicus cows had greater oocyte quality, greater numbers of viable oocytes and greater in vitro embryo yield than Bos taurus. [ABSTRACT FROM AUTHOR]

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., Competing Interests: Declaration of Competing Interest All authors declare that they do not have any actual or potential conflict of interest including any financial, personal or other relationships with other people or organizations., (Copyright © 2022. Published by Elsevier Inc.)

This study aimed to evaluate the effects of hCG treatment during the early luteal phase on ovarian function, progesterone profile, and embryo yield in superovulated ewes. Superovulated sheep were randomly assigned to receive 300 IU hCG i.m. (GhCG, n = 24) or not (GControl, n = 25) at 96 h after the removal of the progesterone (P4) device (D13). Non-surgical embryo recovery (NSER) was performed eight days after P4 withdrawal. Ultrasound evaluations were performed on D13, D14, D16, and D17. Blood samples were collected on D14, D16, and D17. Superovulation scores were recorded based on the number of corpora lutea (CL) as follows: 1 (≤ 2), 2 (3-5), 3 (6-8), and 4 (≥ 9). NSER efficiency, superovulation response, and luteal tissue area were similar in both groups (P > 0.05). Structural luteolysis tended to be higher in GControl (P = 0.07; 47.0 %) while functional luteolysis was similar in both groups (P > 0.05; 0.0 % and 5.9 %). The recovery rate was greater (P < 0.05) in GhCG (89.8 %) compared with GControl (71.0 %), with similar overall ova/embryo numbers observed for both groups (P > 0.05). GhCG showed a higher concentration of animals with a superovulatory response score of 4 (54.5 %; P < 0.05) compared with the lowest scores. Plasma progesterone on D16 was higher (P < 0.05) in GhCG ewes (11.1 ± 1.5 vs 6.9 ± 1.5 ng/mL). In conclusion, the hCG treatment improved circulating P4 and embryo recovery rate, tended to maintain luteal functionality, and thus constitutes an additional tool for improving embryo yield in superovulated ewes., Competing Interests: Declaration of Competing Interest Authors declare that they do not have any actual or potential conflict of interest including any financial, personal, or other relationships with other people or organizations., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The present study determined i) the presence of proteins (oviduct-specific glycoprotein, OVGP1; heat shock protein-70A, HSPA1A; heat shock protein-A8, HSPA8; annexin A1, ANXA1; annexin A5, ANXA5; and myosin-9, MYH9) known to be involved in early reproduction in the oviduct fluid (OF) of anestrous goats; and ii) the functional effect of during IVF on polyspermy modulation and embryonic development. In vitro-matured oocytes were co-cultured with spermatozoa (1.0, 2.0, or 4.0 x 10 6  cells/mL) for 18 h in SOF medium supplemented with 5 μg/mL of heparin, 4 μg/mL gentamicin, and 10% estrus sheep serum (CTRL1, CTRL2, and CTRL4 groups) or the same medium plus 10% OF (OF1, OF2, and OF4 groups) obtained from anestrus goats. The analysis of OF by western blotting confirmed the presence of the six proteins tested for. The increase in sperm concentration had no effect (P > 0.05) on the penetration rate in any group; however, monospermy rate decreased as sperm concentration was increased in both OF and CTRL. Regardless of the concentration used, when data were pooled, OF supplementation improved (P < 0.05) monospermy and tended (P = 0.057) to enhance IVF efficiency. Additionally, IVF efficiency was higher (P < 0.05) in OF1 than in OF4 [60 ± 13 vs 37 ± 5%). The development capacity was not affected (P > 0.05) by the sperm concentration and OF treatment, and the average values were cleavage (72 ± 2.6%), blastocyst (37 ± 3.0%), blastocyst in relation to the cleaved (51 ± 4.8%), hatched (62 ± 1.2%), and number of cells per blastocyst (174 ± 1.8%). In conclusion, the six proteins analyzed are present in the OF of anestrous goats, and the supplementation of this OF during IVF may modulate the polyspermy incidence and enhance IVF efficiency, especially when 1x10 6 sperm per mL is used., Competing Interests: Declaration of competing interest None of the authors have any conflict of interest to declare., (Copyright © 2021 Elsevier Inc. All rights reserved.)

This study evaluated the role of progesterone (P 4 ) and medroxyprogesterone acetate (MAP) on the molecular status of immature cumulus-oocyte complexes (COCs) and the implications for oocyte quality in sheep. The number of viable COCs per ewe and the rate of COCs screened for developmental competence by brilliant cresyl blue positive (BCB + ) were similar (P > 0.05), respectively, across treatments (P 4 : 7.7 ± 0.7 and 4.7 ± 1.2; MAP: 5.7 ± 1.0 and 3.5 ± 2.3; and control: 5.7 ± 1.1 and 3.6 ± 2.4). The COCs' gene expression was altered by exogenous progestogens compared with the control group: markers of steroidogenic pathway (FSH receptor [FSHr], LH receptor [LHr], and estradiol receptor α) and of quality (zygote arrest 1, growth differentiation factor 9, and B-cell lymphoma 2) were in abundance in P 4 (P < 0.05). In addition, reelin protein (RELN) was downregulated, and Bcl-2 was upregulated in MAP (P < 0.05). In the P 4 vs MAP comparison, FSHr, LHr, and RELN genes were upregulated (P < 0.05) in the P 4 group. In conclusion, P 4 and MAP promoted dissimilar effects on transcriptome profiling of immature BCB-selected COCs, possibly due to the differences in the chemical structure of progestogens and concentrations of serum P 4 . Exogenous P 4 impacted positively on the profile of genes related to oocyte quality., (Copyright © 2020. Published by Elsevier Inc.)

The effect of short-term administration of medroxyprogesterone acetate (MPA) or natural progesterone (P 4 ) during ovarian stimulation with FSH on oocyte recovery was investigated in Santa Inês ewes. Ewes were treated with an intravaginal sponge containing MPA for 6 d; GnRH was applied 36 h after sponge removal and FSH was given in 3 injections (40, 24, and 16 mg, respectively) every 12 h after (D0, approximate ovulation time). At the first FSH dose, the ewes received either a new MPA sponge (n = 10) or a controlled device for internal release impregnated with P 4 (n = 10) or did not receive any device (n = 10). Ovarian dynamics were assessed every 12 h by transrectal ultrasonography from D-3 to D2. Oocytes were recovered by laparoscopic ovum pick-up (LOPU) on D2 and graded by morphologic quality. The number of small, medium, and large follicles at D0 and D2 (ultrasound examinations), number of both follicles aspirated and oocytes recovered at LOPU, recovery rate, and oocyte grade did not differ (P > 0.05) among treatments. Thus, the short-term use of MPA or P 4 during ovarian stimulation did not affect the first-wave follicle population or morphologic quality of oocytes. We would suggest that, in this protocol, the use of exogenous progestin is unnecessary., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The CD44 family belongs to a larger group of hyaluronic acid-binding proteins and plays important roles in oocyte maturation, fertilization and preimplantational embryo development. We analyzed the CD44 receptor in sheep oocytes and embryos. Immature oocytes (N = 66) were obtained from a local abattoir; mature oocytes (N = 35) and embryos (N = 41) were obtained by laparotomy from adult hair ewes submitted to ovarian stimulation treatment. The CD44 mRNA was detected by hemi-nested PCR, after reverse transcription, while proteins were located by indirect immunofluorescence, using anti-human CD44 monoclonal antibody. Human lymphocytes and immature bovine oocytes were used as positive and negative controls, respectively. Assessment of the oocyte nuclear stages as well as classification of the embryonic development stage were made with Hoechst 33342 staining. Indirect immunofluorescence detected CD44 expression on the surface of mature oocytes and embryos; immature oocytes did not take up the stain. These findings were supported by the RT-PCR data, which showed no mRNA templates for CD44, even after two consecutive amplifications, in material from immature oocytes and cumulus cells. The CD44 amplicons were detected after a second hemi-nested PCR in mature oocytes and embryos. The finding of CD44 in mature oocytes and preimplantational embryos could reflect the expression profile of hyaluronic acid during terminal folliculogenesis and preimplantational embryo development in sheep.