RESUMO

Oxidative stress is an undesirable effect of in vitro culture, which requires antioxidant supplementation. This study investigated the analogue of resveratrol (RA33) as an alternative to resveratrol, an antioxidant molecule, for the in vitro culture of in vitro-fertilized bovine embryos. The effect of different concentrations of RA33 on embryo development was evaluated and a comparison between RA33 and resveratrol was performed. The cleavage rate was higher (P < 0.05) with 2.5 µM (69.0 ± 4.4%) than at 0, 0.1 or 0.5 µM RA33 (62.1 ± 2.0%, 60.7 ± 5.9% and 56.7 ± 5.8%, respectively). The blastocyst rates on days 7 and 8 post-fertilization with 2.5 µM RA33 (19.4 ± 3.3% and 24.6 ± 3.3%, respectively) were higher (P < 0.05) than for 0 µM (12.4 ± 2.5% and 15.2±2.5%, respectively). When 2.5 µM RA33 was compared with 0.5 µM resveratrol, similar (P > 0.05) cleavage and blastocyst rates were found between them, but the cleavage rate was higher (P < 0.05) in the control (80.8 ± 3.4%) than for the resveratrol treatment (76.4 ± 3.6%). The numbers of apoptotic cells and the apoptotic index were lower (P < 0.05) with RA33 (6.5 ± 0.6 cells and 6.4 ± 0.7%, respectively) and resveratrol (5 ± 0.8 cells and 5.5 ± 1.0%, respectively) than in the control group (9.8 ± 1.2 cells and 8.9 ± 1.1%, respectively). In conclusion, RA33 can enhance the preimplantation development of in vitro-fertilized bovine embryos and be an alternative to resveratrol in embryo culture medium.

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RESUMO

We aimed to evaluate the morphological ovarian response to equine chorionic gonadotropin (eCG) prior to ovum pick-up (OPU) and its effects on the molecular phenotype of immature cumulus-oocyte complexes (COCs) from Nelore cow (Bos indicus) donors. To this end, 20 Nelore cows were distributed randomly into the synchronized-OPU (Sync-OPU) and synchronized plus stimulated-OPU (Sync + eCG-OPU) groups using a cross-over experimental design, as each cow was used in both treatments. On a random day of the estrus cycle (Day 0), all cows received an intravaginal implant with 1.0 g of progesterone and 2 mg IM of estradiol benzoate. On the morning of Day 3, only the Sync + eCG-OPU group received 400 IU of eCG IM. On the morning of Day 5, the P4 device was removed and OPU was conducted in both groups. Before OPU management, ultrasonography was used to identify and measure the follicles. The aspirated COCs were morphologically classified based on their cumulus cells (CC) layers and the texture of the ooplasm. The COCs classified as Grade 1, Grade 2, and Grade 3 were considered viable and used for the assessment of quality markers. Oocytes and CC were mechanically separated from pools of 25 immature COCs of the Sync-OPU and Sync + eCG-OPU groups immediately after the follicular aspiration and stored at -80 °C until RNA extraction. Relative quantification of several markers for oocyte quality was assessed by RT-qPCR. The eCG treatment increased the number of follicles sized 3.0-5.0 mm and >5.0 mm compared to that in Sync-OPU group. Moreover, the protocol with eCG improved the total number of oocytes and the number of viable oocytes, which is related to a high number of oocytes in Grade 3. Regarding the impact on transcriptional regulation in immature oocytes, the mRNA encoding BMP15, SMAD1, SMAD2, SMAD3, ACACA, and CPT1A was upregulated in Sync + eCG-OPU compared with the Sync-OPU group. Moreover, the relative mRNA abundance of CTSZ, a member of the cathepsins family functionally related to reduced oocyte competence, was lower in the Sync + eCG-OPU group than in the Sync-OPU group. In addition, CC CTSB, CTSS, and CTSK mRNA abundances were lower in the Sync + eCG-OPU group than in the Sync-OPU group. However, the relative abundance of AREG and EREG mRNA was higher in CC recovered from cows stimulated with eCG. In conclusion, the eCG approach addressing follicular stimulation in Nelore cows had a positive impact on early antral follicle development, followed by a positive morphological and molecular phenotype in bovine COCs.

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RESUMO

Objetivou-se comparar o tamanho e o fluxo sanguíneo do corpo lúteo (CL) no momento da transferência embrionária com a taxa de prenhez de receptoras bovinas. Utilizou-se duzentas e sessenta e seis (n = 266) receptoras azebuadas previamente sincronizadas. O dia esperado para a ovulação foi considerado o D0 experimental. Sete dias após (D7), classificou-se os CL desses animais quanto ao tamanho (grande, médio ou pequeno) e ao fluxo sanguíneo (intenso, regular e baixo) por ultrassonografia em modo-B e Doppler. Posteriormente, os embriões foram transferidos. Após 23 dias (D30), realizou-se o diagnóstico gestacional. Comparou-se a taxa de prenhez pelo teste de qui-quadrado e probabilidades (P 0,05) nas taxas de prenhez quanto ao fluxo sanguíneo no DG30 (36,1%, 40% e 35,2%, respectivamente, para fluxo intenso, regular e baixo). Entretanto, receptoras com CL de tamanho médio apresentaram maior taxa de prenhez comparadas a receptoras com CL de tamanho pequeno (43,3% VS 17,6%, respectivamente; (P < 0,04). Conclui-se que o tamanho do CL é mais importante que o fluxo sanguíneo em predizer a taxa de prenhez. Entretanto, essa interpretação deve ser cuidadosa devido ao baixo número de receptoras transferidas com CL pequeno.

The objective of this study was to compare the size and blood flow of the corpus luteum (CL) before embryo transfer with the pregnancy rate of bovine recipients. Previously synchronized crossbred recipients (n = 266) were used. The expected day for ovulation was considered the experimental D0. Seven days after (D7), the CL of these animals were classified according to size (large, medium or small) and blood flow (intense, regular and low) by Bmode and Doppler ultrasonography. Subsequently, the embryos were transferred. After 23 days (D30), the gestational diagnosis was performed. The pregnancy rate was compared using the chi-square test (P 0.05) in the pregnancy rate observed in D30 (36.1%, 40% and 35.2%, respectively). Recipients with medium CL had higher pregnancy rate than animals with small CL (43,3% vs 17,6%, respectively;(P < 0.04). Concluding that CL blood flow is not useful for the selection of recipients with a greater chance of becoming pregnant. However, CL size seems to be a good parameter to rule out animals with a lower chance of gestation.

Assuntos

RESUMO

Objetivou-se comparar o tamanho e o fluxo sanguíneo do corpo lúteo (CL) no momento da transferência embrionária com a taxa de prenhez de receptoras bovinas. Utilizou-se duzentas e sessenta e seis (n = 266) receptoras azebuadas previamente sincronizadas. O dia esperado para a ovulação foi considerado o D0 experimental. Sete dias após (D7), classificou-se os CL desses animais quanto ao tamanho (grande, médio ou pequeno) e ao fluxo sanguíneo (intenso, regular e baixo) por ultrassonografia em modo-B e Doppler. Posteriormente, os embriões foram transferidos. Após 23 dias (D30), realizou-se o diagnóstico gestacional. Comparou-se a taxa de prenhez pelo teste de qui-quadrado e probabilidades (P < 0,05) foram consideradas significativas. As análises foram processadas no programa SAS versão 9.4 (SAS University Edition, EUA). Não houve diferença (P > 0,05) nas taxas de prenhez quanto ao fluxo sanguíneo no DG30 (36,1%, 40% e 35,2%, respectivamente, para fluxo intenso, regular e baixo). Entretanto, receptoras com CL de tamanho médio apresentaram maior taxa de prenhez comparadas a receptoras com CL de tamanho pequeno (43,3% VS 17,6%, respectivamente; (P < 0,04). Conclui-se que o tamanho do CL é mais importante que o fluxo sanguíneo em predizer a taxa de prenhez. Entretanto, essa interpretação deve ser cuidadosa devido ao baixo número de receptoras transferidas com CL pequeno.(AU)

The objective of this study was to compare the size and blood flow of the corpus luteum (CL) before embryo transfer with the pregnancy rate of bovine recipients. Previously synchronized crossbred recipients (n = 266) were used. The expected day for ovulation was considered the experimental D0. Seven days after (D7), the CL of these animals were classified according to size (large, medium or small) and blood flow (intense, regular and low) by Bmode and Doppler ultrasonography. Subsequently, the embryos were transferred. After 23 days (D30), the gestational diagnosis was performed. The pregnancy rate was compared using the chi-square test (P < 0.05). The analyzes were processed by the SAS software version 9.4 (SAS University Edition, USA). The recipients with intense, regular and low blood flow did not differ (P > 0.05) in the pregnancy rate observed in D30 (36.1%, 40% and 35.2%, respectively). Recipients with medium CL had higher pregnancy rate than animals with small CL (43,3% vs 17,6%, respectively;(P < 0.04). Concluding that CL blood flow is not useful for the selection of recipients with a greater chance of becoming pregnant. However, CL size seems to be a good parameter to rule out animals with a lower chance of gestation.(AU)

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RESUMO

The aim of the present study was to evaluate the effect of differences in body weight gain after embryo transfer on the pregnancy rates of crossbred heifers used as recipients and raised under a grazing system. The study was performed during the dry (April to September) and the rainy (October to March) seasons. The embryos transferred were produced by in vitro fertilization. The body weight of each recipient was measured immediately before the embryo transfer and 23 to 25 days later, when the diagnosis of pregnancy was performed by ultrasonography. The associations among initial body weight (IBW), daily body weight gain (DWG), season, and pregnancy rate were evaluated using a logistic procedure that included the effect of the IBW, season, and linear and quadratic effects of the DWG. Altogether, there was no effect of season and pregnancy rates did not change between the dry and rainy seasons (42.3 vs. 45.8%, respectively; P > 0.05). However, the pregnancy rate was greater in the recipients with daily body weight gains over 250 g/day, regardless of the season. In addition, the pregnancy rate of the recipients was better (P < 0.04) explained by a logistic regression model that included the linear and quadratic effects of the DWG. The probability of each heifer to become pregnant according to DWG is explained by the follow equation: P(y = 1) = (Exp((-1.06703 + 0.0108 * DWG - 0.00002 * DWG ^ 2)))/(1 + Exp((-1.6703 + 0.0108 * DWG - 0.00002 * DWG ^ 2))). In conclusion, body weight gain potential is a critical factor for the pregnancy rates of in vitro embryo recipients managed under grazing systems.

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RESUMO

Observaram-se os efeitos do sulfato de cefquinoma associado ou não ao cloprostenol no tratamento de retenção de placenta (RP) em vacas leiteiras. Foram avaliadas 687 vacas, destas, 113 apresentaram RP. Os animais foram divididos em dois grupos: Grupo CEF (n=55): 3 doses de 1mg/kg de sulfato de cefquinoma e Grupo CEF+CLOP (n=58): receberam 3 doses de 1mg/kg de sulfato de cefquinoma e 2 doses de 0,530 mg de cloprostenol. Entre o 25º ao 35º dia pós-parto, observou-se à presença de infecções uterinas, nas negativas, o intervalo do parto ao primeiro serviço e do parto à concepção e taxas de concepção total e condicional aos 120 dias pós-cobertura. O tratamento com sulfato de cefquinoma não apresentou diferenças significativas (P>0,05) em relação à associação do cloprostenol. Entretanto, o cloprostenol foi benéfico em relação às taxas de concepção: 96% para o Grupo CEF+CLOP e 88% para o Grupo CEF (88%).

We observed the effects of cefquinome sulphate, associated or not to the treatment of cloprostenol retained placenta (RP) in dairy cows. 687 cows were evaluated, of these, 113 had RP. The animals were divided into two groups: CEF (n = 55): 3 doses of 1mg/kg cefquinome sulphate and CLOP + CEF group (n = 58) received 3 doses of 1mg/kg cefquinome sulphate and 2 doses of 0.530 mg of cloprostenol. Between 25 to 35 days postpartum, we observed the presence of uterine infections in the negative, the interval from calving to first service and calving to conception and conception rates and total conditional at 120 days post-coverage. Treatment with Cefquinome sulphate showed no significant differences (P> 0.05) in relation to the association of cloprostenol. However, cloprostenol was beneficial in relation to conception rates: 96% for Group + CEF CLOP and 88% in group CEF (88%).

Assuntos

RESUMO

Observaram-se os efeitos do sulfato de cefquinoma associado ou não ao cloprostenol no tratamento de retenção de placenta (RP) em vacas leiteiras. Foram avaliadas 687 vacas, destas, 113 apresentaram RP. Os animais foram divididos em dois grupos: Grupo CEF (n=55): 3 doses de 1mg/kg de sulfato de cefquinoma e Grupo CEF+CLOP (n=58): receberam 3 doses de 1mg/kg de sulfato de cefquinoma e 2 doses de 0,530 mg de cloprostenol. Entre o 25º ao 35º dia pós-parto, observou-se à presença de infecções uterinas, nas negativas, o intervalo do parto ao primeiro serviço e do parto à concepção e taxas de concepção total e condicional aos 120 dias pós-cobertura. O tratamento com sulfato de cefquinoma não apresentou diferenças significativas (P>0,05) em relação à associação do cloprostenol. Entretanto, o cloprostenol foi benéfico em relação às taxas de concepção: 96% para o Grupo CEF+CLOP e 88% para o Grupo CEF (88%). (AU)

We observed the effects of cefquinome sulphate, associated or not to the treatment of cloprostenol retained placenta (RP) in dairy cows. 687 cows were evaluated, of these, 113 had RP. The animals were divided into two groups: CEF (n = 55): 3 doses of 1mg/kg cefquinome sulphate and CLOP + CEF group (n = 58) received 3 doses of 1mg/kg cefquinome sulphate and 2 doses of 0.530 mg of cloprostenol. Between 25 to 35 days postpartum, we observed the presence of uterine infections in the negative, the interval from calving to first service and calving to conception and conception rates and total conditional at 120 days post-coverage. Treatment with Cefquinome sulphate showed no significant differences (P> 0.05) in relation to the association of cloprostenol. However, cloprostenol was beneficial in relation to conception rates: 96% for Group + CEF CLOP and 88% in group CEF (88%). (AU)

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RESUMO

Avaliou-se a sincronização folicular e vascularização na parede do folículo dominante (FD) após o tratamento com Cipionato (CE) ou Benzoato de estradiol (BE). No Experimento 1, 45 novilhas receberam implante de P4 (1,0g) e foram distribuídas em 3 grupos de acordo com éster de estradiol administrado pela via intramuscular: 1mL salina; 0,5mg CE ou 2,0mg BE. O diâmetro do FD e a emergência folicular (EF) foram monitorados por 5 dias. No experimento 2, D0 (dia 0): 30 novilhas receberam implante de P4 e 2,0mg BE; D8, retirada do implante e 0,5mg de prostaglandina (cloprostenol); D9: tratamentos: 1mL salina; 0,5mg CE ou 1,0mg BE. O diâmetro e a vascularização do FD foram monitorados do D8 ao D10. Os dados foram analisados por ANOVA ou Kruskal-Wallis, e as médias comparadas por Tukey (5%). No experimento 1, a EF ocorreu mais tarde (P 0,0013) no grupo BE (4,3±0,8 vs. 3,5±0,8d). No experimento 2, o fluxo sanguíneo do FD aumentou (P 0,001) 24h após o tratamento com BE. A taxa de ovulação foi semelhante (P>0,05) entre os grupos (80,0, 70,0 e 55,5%, BE, CE e salina). Conclui-se que nas concentrações utilizadas, o BE, no início do protocolo, retardou a EF e, no final do protocolo, promoveu uma melhor sincronia do FD demonstrada pela elevação do fluxo sanguíneo.(AU)

The study aimed to evaluate synchronization and blood flow of the dominant follicle (DF) after estradiol cypionate (EC) or benzoate(EB) treatment. In experiment 1, progesterone (P4) implants (1.0g) were inserted in 45 heifers, which were given 1mL saline,0.5mg EC or 2.0mg EB. The diameter of the DF and follicle emergence (FE) were recorded for 5 days. For experiment 2, 30 heiferswere given: D0 (day 0): P4 implant and 2.0mg EB; D8: implant removal and 0.5mg of prostaglandin (cloprostenol). On D9, theywere assigned in 1mL saline, 0.5mg EC or 1.0mg EB. From D8 to D10, the diameter and blood flow of the DF was monitored.Data were analyzed by ANOVA or Kruskal-Wallis test, and compared by Tukey (5%). In experiment 1, the FE occurred later(P<0.0013) in EB group (4.3±0.8 vs. 3.5±0.8d). In experiment 2, blood flow of the DF increased (P<0.001) 24h after EB treatment.The ovulation rate was similar (P>0.05) between groups (80.0, 70.0 and 55.5%, EB, EC and saline). The interpretation was that,in these concentrations, the EB, at the beginning, delayed FE and, at the end of the protocol, promoted a better synchrony of theDF, confirmed by the increase of the blood flow.(AU)

Assuntos

RESUMO

Avaliou-se a sincronização folicular e vascularização na parede do folículo dominante (FD) após o tratamento com Cipionato (CE) ou Benzoato de estradiol (BE). No Experimento 1, 45 novilhas receberam implante de P4 (1,0g) e foram distribuídas em 3 grupos de acordo com éster de estradiol administrado pela via intramuscular: 1mL salina; 0,5mg CE ou 2,0mg BE. O diâmetro do FD e a emergência folicular (EF) foram monitorados por 5 dias. No experimento 2, D0 (dia 0): 30 novilhas receberam implante de P4 e 2,0mg BE; D8, retirada do implante e 0,5mg de prostaglandina (cloprostenol); D9: tratamentos: 1mL salina; 0,5mg CE ou 1,0mg BE. O diâmetro e a vascularização do FD foram monitorados do D8 ao D10. Os dados foram analisados por ANOVA ou Kruskal-Wallis, e as médias comparadas por Tukey (5%). No experimento 1, a EF ocorreu mais tarde (P 0,0013) no grupo BE (4,3±0,8 vs. 3,5±0,8d). No experimento 2, o fluxo sanguíneo do FD aumentou (P 0,001) 24h após o tratamento com BE. A taxa de ovulação foi semelhante (P>0,05) entre os grupos (80,0, 70,0 e 55,5%, BE, CE e salina). Conclui-se que nas concentrações utilizadas, o BE, no início do protocolo, retardou a EF e, no final do protocolo, promoveu uma melhor sincronia do FD demonstrada pela elevação do fluxo sanguíneo.

The study aimed to evaluate synchronization and blood flow of the dominant follicle (DF) after estradiol cypionate (EC) or benzoate(EB) treatment. In experiment 1, progesterone (P4) implants (1.0g) were inserted in 45 heifers, which were given 1mL saline,0.5mg EC or 2.0mg EB. The diameter of the DF and follicle emergence (FE) were recorded for 5 days. For experiment 2, 30 heiferswere given: D0 (day 0): P4 implant and 2.0mg EB; D8: implant removal and 0.5mg of prostaglandin (cloprostenol). On D9, theywere assigned in 1mL saline, 0.5mg EC or 1.0mg EB. From D8 to D10, the diameter and blood flow of the DF was monitored.Data were analyzed by ANOVA or Kruskal-Wallis test, and compared by Tukey (5%). In experiment 1, the FE occurred later(P0.05) between groups (80.0, 70.0 and 55.5%, EB, EC and saline). The interpretation was that,in these concentrations, the EB, at the beginning, delayed FE and, at the end of the protocol, promoted a better synchrony of theDF, confirmed by the increase of the blood flow.

Assuntos