No abstract

Piau porcine blastocysts were submitted to MALDI-TOF to identify the main phospholipids (PL). After that, in vivo blastocysts (D6) were vitrified (n=52), non-vitrified were used as control (n=42). After warming, blastocysts were in vitro cultured to assess re-expansion and hatching at 24 and 48 hours. Finally, at 48 hours, hatched blastocysts were submitted to RT-qPCR searching for BCL2A1, BAK, BAX and CASP3 genes. For MALDI-TOF, the ion intensity was expressed in arbitrary units. Blastocyst development was compared by Qui-square (P< 0.05). Among the most representative PL was the phosphatidylcholine [PC (32:0) + H]+; [PC (34:1) + H]+ and [PC (36:4) + H]+. Beyond the PL, MALDI revealed some triglycerides (TG), including PPL (50:2) + Na+, PPO (50:1) + Na+, PLO (52:3) + Na+ and POO (52:2) + Na. Re-expansion did not differ (P> 0.05) between fresh or vitrified blastocysts at 24 (33.3%; 32.7%) or 48 hours (2.4%; 13.5%). Hatching rates were higher (P< 0.05) for fresh compared to vitrified at 24 (66.7%; 15.4%) and 48 hours (97.6%; 36.0%). BAX was overexpressed (P< 0.05) after vitrification. In conclusion, Piau blastocysts can be cryopreserved by Cryotop. This study also demonstrated that the apoptotic pathway may be responsible for the low efficiency of porcine embryo cryopreservation.

The present study aimed to investigate the effects of a combination of progesterone with different doses of E-17β on following end points: (1) ovarian follicular dynamics and emergence of a new follicular wave, and (2) superovulatory response and embryo yield. In Experiment 1, 28 ewes were randomly divided into four groups (n = 7) to receive either 2.0 mg, 1.0 mg, 0.5 mg or none E-17β one day after insertion of a progesterone device. The different doses of estradiol similarly delayed the moment of follicular emergence (overall mean = 3.1 ± 1.0 days vs. control group = 0.86 ± 1.0 days; P < 0.01), but the emergence of the new wave showed greater synchronization with the 0.5 mg dosage of E-17β. In Experiment 2, sixtytwo donor ewes received an internal progesterone release device (day -1) for 7 d and 1 d after the insertion of this device (day 0) were allocated randomly to receive 0.5 mg of E-17β or only the vehicle (control group). Superstimulation was initiated on day 3 with the administration of 133 mg of pFSH in eight decreasing doses. Contrary to expectations, the protocol with the administration of 0.5 mg E-17β did not improve the percentage of donors with > 2 CL, the number of CL and the production of embryos (P > 0.05). It was concluded that the combination of progesterone and 0.5 mg E-17β was more efficient in synchronizing the emergence of the new follicular wave, however this approach seems to be unnecessary in ewe's superovulation programs.

Resumo O objetivo deste experimento foi avaliar o efeito da época do ano sobre a biometria testicular e qualidade do sêmen fresco e congelado de touros Pantaneiros. Seis touros foram submetidos, mensalmente, durante um ano, à mensuração testicular e à coleta e congelamento do sêmen, utilizando-se meio à base de tris-gema-glicerol. O comprimento e o volume testiculares foram maiores (P < 0,05) nos meses de junho (11,1±0,8 cm; 652,7±138,0 cm3), julho (11,0±0,9 cm; 616,4±156,2 cm3) e setembro (11,8±0,8 cm; 692,4±141,3 cm3) que em outubro (9,4±1,2 cm; 498,5±154,3 cm3) e novembro (10,3±1,1cm; 560,0±111,8 cm3). A concentração espermática foi maior (P < 0,05) no mês de agosto (1265,0±436,8 x106sptz/mL) que nos meses de outubro, dezembro e janeiro (591,6±192,0; 627,5±314,4; 502,5±172,9 x106 sptz/mL, respectivamente). Não houve efeito da época do ano sobre a qualidade do sêmen fresco e congelado (motilidade, vigor, defeitos totais e integridade acrossomal) (P > 0,05). Conclui-se que touros Pantaneiros, na região do Distrito Federal, podem ser utilizados em programas de acasalamento natural em todas as épocas do ano. Visando ao enriquecimento do Banco Brasileiro de Germoplasma Animal com maior número de doses, sugere-se o congelamento do sêmen entre os meses de junho e agosto, embora este não apresente perda de qualidade nas diferentes épocas do ano.