Follicle and corpus luteum size and vascularity as predictors of fertility at the time of artificial insemination and embryo transfer in beef cattle / Tamanho e vascularização do folículo e corpo lúteo como preditores de fertilidade após inseminação artificial e transferência de embriões em gado de corte

Two ultrasound based fertility prediction methods were tested prior to embryo transfer (ET) and artificial insemination (AI) in cattle. Female bovines were submitted to estrous synchronization prior to ET and AI. Animals were scanned immediately before ET and AI procedure to target follicle and corpus luteum (CL) size and vascularity. In addition, inseminated animals were also scanned eleven days after insemination to target CL size and vascularity. All data was compared with fertility by using gestational diagnosis 35 days after ovulation. Prior to ET, CL vascularity showed a positive correlation with fertility, and no pregnancy occurred in animals with less than 40% of CL vascularity. Prior to AI and also eleven days after AI, no relationship with fertility was seen in all parameters analyzed (follicle and CL size and vascularity), and contrary, cows with CL vascularity greater than 70% exhibit lower fertility. In inseminated animals, follicle size and vascularity was positive related with CL size and vascularity, as shown by the presence of greater CL size and vascularity originated from follicle with also greater size and vascularity. This is the first time that ultrasound based fertility prediction methods were tested prior to ET and AI and showed an application in ET, but not in AI programs. Further studies are needed including hormone profile evaluation to improve conclusion.

Duas técnicas de predição de fertilidade, baseadas em ultrassonografia, foram testadas no momento da transferência de embriões (TE) e inseminação artificial (IA) em bovinos. Fêmeas bovinas foram submetidas a protocolos de sincronização de estro para TE e IA. Os animais foram escaneados por ultrassonografia imediatamente antes do procedimento de TE e IA para identificar o tamanho e vascularização do folículo e corpo lúteo (CL). Além disso, os animais inseminados foram escaneados onze dias após a inseminação para identificar o tamanho e vascularização do CL. Todos os dados foram comparados com a fertilidade utilizando-se do diagnóstico gestacional 35 dias após a ovulação. No momento da TE, a vascularização do CL apresentou-se positivamente relacionada com a fertilidade, sendo que animais com menos de 40% de vascularização do CL não ficaram gestantes. No momento da IA, assim como onze dias após a IA, nenhuma relação foi encontrada entre fertilidade e os parâmetros analizados (tamanho e vascularização do folículo e CL), enquanto que contrariamente, houve uma queda na fertilidade em vacas com vascularização do CL acima de 70%. Nos animais inseminados, o tamanho e vascularização do folículo foi positivamente relacionado ao tamanho e vascularização do CL, demonstrado pela presença de um CL maior e mais vascularizado proveniente de um folículo maior e mais vascularizado. O presente estudo é o primeiro a mostrar métodos de predição de fertilidade baseados em ultrassonografia no momento da IA e TE, demonstrando uma aplicabilidade prática no momento da TE. Novos estudos são necessários para suportar os resultados mostrados, incluindo análises hormonais.

anatomical structures of sheep cervix and its influence on the transcervical passage of an inseminating catheter into the uterine lumen

A total of 103 Barbari sheep cervices were used to conduct this work. The cervices were allocated into two main series obtained from an abattoir during the breeding season. The first series was 43 of adult ewe cervices, while the second was a series of 60 cervices obtained from ewe lambs. The tract of both series was further subdivided into luteal and follicular phases based on ovarian structure. The morphology of the cervical external os was classified as slit, papilla, duckbill, flap or rose. An inseminating pipette was inserted into the cervical lumen and the depth of penetration was recorded. The cervix was opened longitudinally, its length and number of cervical rings and its arrangement were recorded. Theresults revealed that there was a significant [P < 0.01] effect of age on the length of the cervix. Similarly, the length of cervix was significantly [P < 0.001] related to the number of cervical rings but not to the stage of the oestrous cycle. The maximum depth of cervical penetration of an inseminating catheter was affected by cervical grade and the stage of the oestrous cycle. The distribution of os types differed with age, with rose types were more common in adult ewes, and papilla os types were more common in ewe lambs. In conclusion, the success of transcervical artificial insemination [TCAI] in ewes is highly dependent on the anatomy of the cervical lumen and the stage of the oestrous cycle

Aspectos éticos y bioéticos de la reproducción asistida y manipulación genética en Bolivia / Aspects ethics and bioethics of the reproduction attende and manipulation genetic in Bolivia

Los modernos avances y descubrimientos científicos y tecnológicos, y en especial en los campos de la Biomedicina y la Biotecnología, han posibilitado, entre otros, el desarrollo y utilización de técnicas de reproducción alternativas a la esterilidad de la pareja humana, generalmente conocidas como Técnicas de Reproducción Asistida o Artificial, algunas de ellas imaginables hasta hace algún tiempo. De ellas, la Inseminación Artificial (IA) con semen del marido o de la pareja (IAC) o con semen de donante (IAD), se viene realizando desde hace varios años. La Fecundación In Vitro (FIV) con transferencia de embriones (TE), de mayor complejidad técnica, se dio a conocer universalmente en 1978 con el nacimiento de Louise Brown, en el Reino Unido, mientras que en nuestro país, el primero de los hoy ya varios nacimientos por esta técnica tuvo lugar en la ciudad de Santa Cruz el año 1993. Actualmente ya se están aplicando en nuestro medio las técnicas de micromanipulación de gametos, como la Inseminación Intracitoplasmática de espermatozoides (ICSI) que consiste en la inyección de un solo espermatozoide directamente dentro del citoplasma del óvulo, tecnología altamente sofisticada y costosa