Effect of single dose follicle stimulating hormone on follicular aspiration, in vitro fertilization and pregnancy rate / Efeito do hormônio folículo estimulante em dose única na aspiração folicular, fertilização in vitro e taxa de prenhez

The present study evaluated Brangus cows treated with single doses of follicle stimulating hormone (FSH) subjected to follicular aspiration after 24 h to assess oocyte recovery, in vitro fertilization and pregnancy rate. Follicles exceeding 3 millimeters in diameter were aspirated, 200 mg of FSH was administered 2 days later, and a new ovum pickup was performed 24 h afterward. These methods were performed 3 times every 3 days. In control, follicular aspirations occurred at intervals of 1-week without FSH administration o. The aspirated oocytes were evaluated, submitted to in v itrofertilization and the embryos were transferred to the recipients. The average recovery of oocytes was higher (p<0.05) in control cows (12.4±1.8) than in treated cows (9.4±1.3). There was no difference (p>0.05) in the mean percentage of viable oocytes (52.0±3.9 and 62.7±4.7%) or the mean percentage of embryos (41.4±4.8 and 41.5±4.2%) among control and treated cows, respectively. The mean percentage of pregnancy did not differ (p>0.05) for control cows (43.8±2.7%), and treated cows (40.9±6.8%). In conclusion, FSH treatment did not improve oocyte recovery, in vitro fertilization, and pregnancy percentage. However, there is possibility of several consecutive ovum pickup every t3 days, concentrating the in vitro fertilization and the pregnancy percentage.

O presente estudo avaliou vacas Brangus tratadas com doses únicas de hormônio folículo estimulante (FSH) submetidas a aspiração folicular após vinte e quatro horas, para avaliação da recuperação oocitária, fertilização in vitro e taxa de prenhez. Folículos superiores a três milímetros de diâmetro foram aspirados, 200 mg de FSH foram administrados dois dias depois e uma nova aspiração folicular foi realizada 24 horas após. Esses métodos foram efetivados três vezes a cada três dias. No controle, as aspirações foliculares ocorreram em intervalos de uma semana sem administração de FSH. Os oócitos aspirados foram avaliados, submetidos à fertilização in vitro e os embriões foram transferidos em receptoras. A recuperação média dos oócitos foi superior (p<0,05) nas vacas controle (12,4±1,8) do que nas vacas tratadas (9,4±1,3). Não houve diferença (p>0,05) na porcentagem média de oócitos viáveis (52,0±3,9 e 62,7±4,7%) ou na porcentagem média de embriões (41,4±4,8 e 41,5±4,2%) entre vacas controle e vacas tratadas, respectivamente. A porcentagem média de prenhez não diferiu (p>0,05) para as vacas controle (43,8±2,7%) e as tratadas (40,9±6,8%). Em conclusão, o tratamento com FSH não melhorou a recuperação de oócitos, a fertilização in vitro e o percentual de prenhez. No entanto, existe a possibilidade de várias aspirações foliculares consecutivas a cada três dias, concentrando a fertilização in vitro e o percentual de prenhez.

A historical perspective of embryo-related technologies in South America

Livestock production is of great importance for the economy of most South American countries, a region that accounts for 23.0% of the world cattle population (Food Agriculture Organization - FAO, 2017). Not surprisingly, the embryo industry is historically very active in this region, particularly in Argentina and Brazil. The field of bovine embryo transfer underwent a remarkable change in the past two decades in Brazil, mainly due to in vitro embryo production (IVEP). Total embryo production increased dramatically, along with constant changes in the main features of the embryo industry from market niches to mass production, from beef to the dairy sector, from zebu to European breeds. Recently, IVEP has also emerged in other South American countries. This review summarizes and describes factors driving the changes in the Brazilian embryo industry and discusses some of the impacts upon other embryo-related technologies.(AU)

A historical perspective of embryo-related technologies in South America

Livestock production is of great importance for the economy of most South American countries, a region that accounts for 23.0% of the world cattle population (Food Agriculture Organization - FAO, 2017). Not surprisingly, the embryo industry is historically very active in this region, particularly in Argentina and Brazil. The field of bovine embryo transfer underwent a remarkable change in the past two decades in Brazil, mainly due to in vitro embryo production (IVEP). Total embryo production increased dramatically, along with constant changes in the main features of the embryo industry – from market niches to mass production, from beef to the dairy sector, from zebu to European breeds. Recently, IVEP has also emerged in other South American countries. This review summarizes and describes factors driving the changes in the Brazilian embryo industry and discusses some of the impacts upon other embryo-related technologies.

Use of in vitro fertilization technique in the last decade and its effect on Brazilian embryo industry and animal production

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.