Taxa de recuperação in vivo e competência in vitro de oócitos bubalinos, zebuínos e taurinos aspirados em diferentes fases da onda de crescimento folicular.

Abstract

Arango, Cindy Libeth Vilanueva, Tassia Gonçalves, Carol Destro, Mariana Raposo, Diego Souza, Gustavo Calomeni, Rodrigo Gardinal, César Caetano, Gabriel Gomes, Natália, Milena, Mineiro, Tito, Peter, Gisele Greghi, Mariângela Fernanda, André, pela Chapter 1, 30 crossbred heifers were submitted to OPU on days 2 (D2), 4 (D4) or 6 (D6) after follicular wave emergence (n=10/ group), in a cross-over design performed in 3 replicates. Oocytes recovered were selected and those viable were submitted to in vitro embryo procedures. Data were analyzed by ANOVA, using PROC MIXED, in which time of OPU, replicate and interaction between these factors were considered as fixed effects, and donor was considered as a random effect. Higher blastocyst rate (6 days after IVF), number of blastocysts (9 days after IVF), and number of nuclei of hatched embryos were produced when OPU was done on D2. However, OPU on D6 also produced a higher blastocyst rate (6 days after IVF), and did not differ from other times of OPU concerning number of nuclei of hatched embryos. In Chapter 2, two experiments were performed. In Experiment 1, the effect of 50 mg of injectable progesterone was evaluated in the synchronization of follicular wave emergence of Nelore, Holstein, and buffalo heifers submitted to a progestin plus 2 mg of estradiol benzoate protocol (n=10/ group). Data were analyzed by logistic regression, by PROC GLIMMIX. The time of follicular wave emergence was not affected by administration of injectable progesterone. Besides, follicular wave emergence occurred between 4.2 and 4.5 days after the beginning of synchronization protocol for all genetic groups. In Experiment 2, the effects of time of OPU relative to follicular wave emergence (1, 3 or 5 days) and of genetic group (Nelore, Holstein, and buffalo) on in vitro embryo production were evaluated. A total of 27 heifers (9 of each genetic group, assigned in the 3 times of OPU) were submitted to 6 OPU sessions, in a cross-over design. Oocytes recovered were selected and those viable were submitted to in vitro embryo procedures. Data were analyzed by ANOVA, using PROC MIXED, in which time of OPU, genetic group, replicate and interaction between these factors were considered as fixed effects, and donor was considered as a random effect. Results demonstrated that Nelore heifers showed a better efficiency for in vitro embryo production than Holstein or buffalo heifers. Additionally, OPU performed at different times of synchronized follicular wave did not influence in vitro embryo production.

Manipulation of Follicle Development to Ensure Optimal Oocyte Quality and Conception Rates in Cattle

“…2010). Recent studies with B. taurus and B. indicus cattle maintained under controlled nutritional and environmental conditions were designed to more fully understand the particularities that may influence the outcomes of OPU‐IVP programmes (Gimenes 2010; Sales 2011). Compared with B. taurus cattle, B. indicus cattle exhibit increased total numbers of oocytes, increased oocyte viability, increased blastocyst rate and a reduced rate of nuclear fragmentation in IVP blastocyst cells (Tables 1 and 2).…”

“…Recently, a study was conducted comparing the day of aspiration relative to the time of the synchronized follicular wave emergence (1, 3 or 5 days after the expected wave emergence) in Holstein and Nelore heifers. The day of OPU relative to the follicular wave emergence did not have an effect on the number of follicles, viable oocytes recovered and blastocyst production, regardless of the breed (Gimenes 2010). Reis et al (2010) evaluated the effect of synchronizing follicular wave emergence in OPU programmes.…”

“…Effect of donor (heifer) genetic group [Bos indicus (Nelore) and Bos taurus (Holstein)] on oocyte recovery rate and oocyte competence to develop into blastocysts in vitro. Adapted fromGimenes (2010) …”

Anti‐Mullerian Hormone Concentration and Antral Ovarian Follicle Population in Murrah Heifers Compared to Holstein and Gyr Kept Under the Same Management

“…Furthermore, Bos indicus cattle have greater numbers of follicles recruited per follicular wave than Bos taurus (Baruselli et al. ; Gimenes ; Baldrighi et al. ).…”

Passive Transfer of Immunity and Serum Proteinogram during the First 35 Days of Age in Nelore Calves Conceived Naturally or Through In Vitro Fertilization

“…O Brasil é o maior produtor mundial de embriões in vitro e isso se deve à participação da raça Nelore, reconhecida pela melhor qualidade dos oócitos recuperados para utilização na fecundação in vitro (FIV) [12]. Apesar de a biotécnica permitir o avanço do melhoramento genético, há relatos de alguns problemas, como tempo de gestação prolongado [25], aumento da mortalidade pré-natal e peso corpóreo elevado ao nascimento, que, juntos, definem a "Síndrome do Bezerro Grande" [31,33].…”