Marco Roberto Bourg de Mello

Effect of seminal plasma and egg yolk concentration on freezability of goat semen

The objective of this study was to evaluate the effects of egg yolk and seminal plasma on the viability of cryopreserved goat semen. To this end, four fertile Saanen bucks, aged between 10 months and 1 year, and weighing 18 to 25 kg, were used. Semen was collected from each buck by the artificial vagina method at the end of breeding season (June-July). The extender used was the yolk citrate, which was split into two equal aliquots: 5% egg yolk (2.5 mL egg yolk: 47.5 mL citrate solution) were added to one of the samples and 10% egg yolk (5.0 mL egg yolk: 45.0 mL citrate solution) were added to another. The sperm motility and vigor after thawing and post thermal resistance test (TRT) were evaluated and the data were subjected to analysis of variance and means were compared by the F test at 5.0% probability. The observed values for motility and vigor after thawing and post thermal resistance test (TRT), fast and slow, according to the presence of seminal plasma and egg yolk percentage were: 5% egg yolk with plasma (25.0% and 3.3; 1.60% and 0.7; 12.36% and 1.6, respectively); 5% egg yolk without plasma (23.61% and 3.1; 1.25% and 0.2; 9.93% and 1.3, respectively); 10% egg yolk with plasma (30.8% and 3.3; 4.4% and 1.9; 19.5% and 2.7, respectively); and 10% egg yolk without plasma (13.4% and 2.5; 4.1% and 0.5; 17.0% and 1.0, respectively). There were significant differences between the analyzed data in relation to semen with or without plasma at different percentages of egg yolk, and the group that presented the best results was 10% egg yolk citrate in extender with plasma. The presence of seminal plasma and higher concentration of egg yolk in extender provide a higher viability of cryopreserved goat semen.

Clonagem de embriões bovinos a partir de células somáticas

No presente artigo revisa-se dedicadamente a literatura do tema da clonagem tentando levar o leitor paulatinamente atraves dos avancos da tecnica ate alcancar as mais novas alternativas propostas pelos cientistas, e incluindo os erros mais comumente acontecidos nelas. A finalidade e mostrar o amplio panorama que tem aberto esta biotecnologia para a humanidade toda.

Maturação e desenvolvimento embrionário in vitro de oócitos bovinos após bloqueio da meiose com inibidores de MPF

This study evaluated the bovine oocyte maturation and embryo development after in vitro fertilization. The maturation of the oocytes was blocked using Butyrolactone I and Roscovitine using pre-maturation medium supplemented with fetal calf serum (FCS). The ocytes were divided in four groups: Control 0 hour, Control (24 hours of maturation), Roscovitine (maturation blockage with 50mM Roscovitine during 24 hours followed by 24 hours of maturation), and Butyrolactone I (maturation blockage with 150mM Butyrolactone I during 24 hours followed by 24 hours of maturation). The oocytes were fixed and stained with aceto orcein to evaluate the nuclear maturation. After the maturation period, the remaining oocytes of the Control group, Roscovitine, and Butyrolactone I were fertilized in vitro. Embryo development was assessed by the cleavage rate (D3) and blastocysts formation (D7). The Butyrolactone I group had similar rates of germinal vesical stage oocytes during blockage, and Metaphase 2 after maturation, comparing to Control group at 0 hour and Control group, respectively. On the other hand, the Roscovitine group had lower rates of vesical stage oocytes during blockage, and Metaphase 2 after maturation comparing to Control groups. After in vitro fertilization, higher rates of cleavage were observed in Control and Butyrolactone I groups. For the blastocyst formation rate, the Control group showed better results than Roscovitine group. In summary, Butyrolactone I group had similar results to the Control group, and for this reason, is suitable for pre-maturation of bovine oocytes using FCS. In contrast, Roscovitine group had lower oocyte maturation and embryo development.

Effect of follicular wave synchronization on superovulatory response of Girolando embryo donors

The objective of this study was to evaluate the effect of the follicular wave synchronization method on the superovulatory response of Girolando embryo donors. Seven cows and five heifers were divided into three treatments according to the method of the follicular wave synchronization prior to superovulation. The donors were superovulated with eight FSH decreasing doses, adding 133 mg per animal. The superovulatory response was evaluated using an ultrasound device to quantify the number of corpora lutea. The number and quality of recovered structures were also evaluated. Animal category (cow or heifer) and genetic group influenced the superovulatory response, in which heifers showed a greater response (100% in all treatments) compared with cows, which showed 85.7%, 57.1% and 57.1% superovulatory response for standing estrus, GnRH and P4 + BE groups, respectively. The genetic group also showed influence on superovulatory response, in which the 3/8 animals had an average of 10.3 corpora lutea per donor compared with the 3/4 animals, which showed 4.9. The follicular wave synchronization treatments did not show differences in superovulatory response, recovered structures and viable structures. The treatment of follicular wave synchronization with GnRH or with P4 + BE can be used in Girolando donors with the same efficiency as the standing estrus group, and 3/8 Girolando heifers respond better to the superovulatory treatment.

Reproductive parameters of Sindhi cows (Bos taurus indicus) treated with two ovulation synchronization protocols

The objective of this study was to evaluate the reproductive parameters of Sindhi cows aiming to improve the efficiency of fixed-time artificial insemination protocols in this breed. For this purpose, sixteen Sindhi cows were divided into two groups: in group I (EB, n = 8) animals received an intravaginal P4 implant and an application of 2 mg of estradiol benzoate on day 0. On day 8 the implant was removed and 10 mg of Dinoprost were applied; on day 9, 1 mg of estradiol benzoate was applied, and animals were fixed-time artificially inseminated 36 hours later; in group II (EB + eCG, n = 8) animals were subjected to same treatment, and on day eight 400 IU of eCG were applied. From day 0 animals were examined daily by a trans-rectal ultrasound device, where in each assessment the largest follicles of each day were measured. The reproductive parameters observed for groups I and II were: emergence of follicular wave, 4.5±1.4 and 3.8±0.3 days; interval between wave emergence and ovulation, 5.8±1.4 and 7.1±0.3 days; interval between wave emergence and implant removal, 3.5±1.4 and 4.1±0.3 days; interval between implant removal and ovulation, 74.0±11.8 and 82.5±4.2 hours; diameter of the dominant follicle (DF) at the time of implant removal, 7.5±2.5 and 6.6±1.5 mm; maximum diameter of DF, 10.47±8.85 and 3.7±1.2 mm; growth rate of DF, 0.90±0.83 and 0.7±0.6 mm/day; ovulation rate, 75% and 100%; and pregnancy rate, 0% and 50%, respectively. There was no significant difference between the groups. We observed that eCG was not efficient in improving the reproductive parameters analyzed in this breed.