RESUMO
This study evaluated the relationship between CL features assessed by ultrasound (luteal tissue area and blood flow, BF) or rectal palpation (size), uterine tone (UT), plasma progesterone (P4) concentration on Day 7 (D7) and subsequent pregnancy outcomes in bovine embryo recipients. A total of 163 cows and heifers were included in this study. The expected day of ovulation after the synchronization protocol was designated as D0. On D7, ovaries and uterus were examined by ultrasonography and rectal palpation, and subjective scores (1-3 scale) were assigned for CL size, area and BF, and for UT. Blood samples were collected for further P4 analysis. Each embryo recipient then received a grade I frozen-thawed in vivo-produced blastocyst, which was transferred to the uterine horn ipsilateral to the CL. Pregnancy diagnosis was performed on D35, and the results were retrospectively compared with the assigned scores for CL and UT. We observed a significant (p < .02) interaction between CL size and UT, with a progressive increase in the likelihood of pregnancy for recipients bearing a large CL among those with turgid UT. Ultrasound scoring of the CL using B-mode and Doppler-mode did not significantly predict pregnancy rates on D35 (p < .6 and p < .5, respectively). However, logistic regression analysis revealed a trend towards a quadratic effect (p < .08 and p < .06) indicating that the probability of pregnancy varied according to the area of luteal tissue and P4 concentrations, respectively. No significant (p > .05) association was found between the probability of pregnancy and the BF area of the CL. In summary, UT before embryo transfer may reflect successful recipient synchronization. Elevated P4 levels, assessed by CL size, may offset uterine contractility, mitigating adverse effects. Additionally, the CL area may be more important than its vascularization area when evaluating recipients D7 after ovulation.
Assuntos
Transferência Embrionária , Progesterona , Útero , Feminino , Animais , Bovinos/fisiologia , Transferência Embrionária/veterinária , Gravidez , Útero/irrigação sanguínea , Útero/diagnóstico por imagem , Progesterona/sangue , Ultrassonografia/veterinária , Corpo Lúteo/fisiologia , Taxa de Gravidez , Sincronização do Estro , Resultado da Gravidez/veterináriaRESUMO
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
Feminino , Animais , Bovinos , Bovinos/embriologia , Bovinos/sangue , Embrião de Mamíferos/diagnóstico por imagem , Ultrassonografia Doppler em Cores/instrumentação , Ultrassonografia Doppler em Cores/veterináriaRESUMO
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)
Assuntos
Animais , Feminino , Bovinos , Bovinos/embriologia , Embrião de Mamíferos/diagnóstico por imagem , Ultrassonografia Doppler em Cores/instrumentação , Ultrassonografia Doppler em Cores/veterinária , Bovinos/sangueRESUMO
The aim of the present study was to evaluate the likelihood of pregnancy of in vitro-produced (IVP) embryos from batches with distinct relative efficiencies. Data were retrospectively analyzed from 605 transvaginal ultrasonic-guided follicle aspiration sessions (OPU) followed by in vitro embryo production (IVEP) and 2456 fresh embryo transfers (ET), performed between 2008 and 2012 in individuals of the Gir (dairy Bos indicus) breed. The OPU and IVEP were performed using standard procedures by a single group of technicians at the same laboratory facility. Records were stratified into quartiles (I to IV) according to the total of cumulus-oocytes complexes (COC) produced per donor, or in percentile ranges (0%-25%, 26%-50%, 51%-75%, and 76%-100%) for endpoints related to COC quality or efficiency of embryo production. Pregnancy per embryo transfer (P/ET) was compared among quartiles or ranges using the chi-squared test. Donors producing a greater number of total COC (quartile I) also had more viable and grade I COC, and a greater number of embryos than donors ranked in quartiles II, III or IV, respectively (Pâ¯<â¯0.0001). Nevertheless, P/ET did not differ (Pâ¯>â¯0.05) among embryos produced by donors ranked in Quartiles I to IV. Similarly, there was no difference (Pâ¯>â¯0.05) in P/ET for embryos derived from OPU sessions with a relatively greater or lesser percentage of viable or Grade I COC. Cleavage and blastocyst rates within each IVEP batch had no effect (Pâ¯>â¯0.05) on P/ET. In conclusion, data suggest that there is no relationship among oocyte yield after OPU, or efficiency of IVEP, and the likelihood of pregnancy after ET of fresh IVP embryos.
Assuntos
Bovinos , Técnicas de Cultura Embrionária , Transferência Embrionária , Fertilização in vitro , Recuperação de Oócitos , Taxa de Gravidez , Animais , Bovinos/embriologia , Bovinos/fisiologia , Células Cultivadas , Técnicas de Cultura Embrionária/métodos , Técnicas de Cultura Embrionária/veterinária , Transferência Embrionária/métodos , Transferência Embrionária/veterinária , Feminino , Fertilização in vitro/métodos , Fertilização in vitro/veterinária , Técnicas de Maturação in Vitro de Oócitos/veterinária , Masculino , Recuperação de Oócitos/métodos , Recuperação de Oócitos/veterinária , Gravidez , Resultado da Gravidez/epidemiologia , Resultado da Gravidez/veterinária , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Brucellosis is an infectious and contagious disease that profoundly impacts public health. However, in many countries, disease prevention is restricted to the vaccination of calves, and there is no prophylactic strategy for pregnant heifers and cows. The aim of this study was to evaluate the safety of the rough strain vaccine against brucellosis in pregnant cattle. Crossbred cows (N = 96) at three gestational periods (early, mid, or late pregnancy) were randomly allocated into the vaccine treatment group or to the control group. We then compared the percentage of pregnancies reaching full term, live calves 60 days after delivery, and seropositive calves. There was no effect of vaccination in any of the gestational periods on the evaluation endpoints. In conclusion, vaccination against brucellosis with the rough strain is safe for pregnant cattle at all gestational periods.
Assuntos
Vacina contra Brucelose/imunologia , Brucella abortus/imunologia , Brucelose Bovina/prevenção & controle , Vacinação/veterinária , Animais , Vacina contra Brucelose/efeitos adversos , Bovinos , Feminino , Parto , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle , Complicações Infecciosas na Gravidez/veterinária , Vacinação/efeitos adversosRESUMO
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.
Assuntos
Bovinos/crescimento & desenvolvimento , Transferência Embrionária/veterinária , Taxa de Gravidez , Aumento de Peso , Aborto Animal , Ração Animal/análise , Criação de Animais Domésticos , Fenômenos Fisiológicos da Nutrição Animal , Animais , Peso Corporal , Bovinos/fisiologia , Dieta/veterinária , Feminino , Gravidez , Estações do AnoRESUMO
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
Feminino , Animais , Bovinos , Estradiol , Fase Folicular/fisiologia , Ovulação , Reprodução/fisiologia , Ultrassonografia Doppler em CoresRESUMO
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
Animais , Feminino , Bovinos , Estradiol , Reprodução/fisiologia , Fase Folicular/fisiologia , Ovulação , Ultrassonografia Doppler em CoresRESUMO
Background: Based on the evaluation of embryo production and transfer numbers, as well as of market changes and trends, we can estimative the impact of the advances in reproductive biotechnology research and development on the productive sector. The aim of the present study was to retrieve the figures and critically evaluate the bovine embryo market in Brazil, considering also the world context and livestock production scenario. Methodology: Data recovered from different breeders associations and related to the number of bovine embryos produced and transferred in 2009 were used. Data of relative efficiency of the embryo biotechnologies were obtained from private companies. Information of the world embryo industry was provided by the International Embryo Transfer Society (IETS). Context analysis was performed using different index from Brazilian government institutes. Results and discussion: According to data retrieved by the Brazilian Embryo Technology Society (SBTE) there was a significant increase in bovine embryo production in Brazil in the last decade. This increase was directly related to the expansion in the use of in vitro embryo production (IVEP), which became the technique of choice to increase the number of offspring from genetically superior animals, mainly in zebu breeds. The growth in the adoption of IVEP resulted in an increased participation of the country in the total of embryos produced in the world and set some of the national market features, such as the low use of cryopreservation and the predominance of beef breeds in this industry. The emergence of semen sexing technology allowed an improvement in the use of IVEP in dairy breeds and was the key for the increase in the total of embryos produced in the last five years. The commercial outcome of IVEP in Brazil is related to a complex interplay of biological and market features including reproductive physiology characteristics of zebu cows, scale of use, and the previous experience with conventional embryo transfer. The association of these features produced a scenario favorable for the IVEP expansion, differently from what was observed in other countries with tradition in the use of conventional embryo transfer. Embryo production in Brazil is positively correlated to different research and development and livestock production indexes, but the association showed a pattern different from the one observed for other reproductive biotechnologies. The new figures of the Brazilian embryo industry and the indirect consequences on genetic progress of the herds and on animal production indicate that IVEP can be a model to study innovation in livestock production, once the advances in the state of the art were followed by the use of new technologies and consequent gains in market values of the products. Conclusion: The use of bovine IVEP technology caused a significant change in the scenario of the Brazilian embryo industry and demonstrated the importance of innovation in livestock production and, consequently, of the investment in science and technology.