Avaliação da qualidade, maturação e desenvolvimento embrionário inicial de oócitos oriundos de folículos de diferentes diâmetros em éguas

Abstract

Equine reproduction has been advancing in recent years with the development and improvement of biotechniques, allowing to increase the reproductive efficiency of animals with high zootechnical value. In relation to the in vitro production of embryos, the equine species presents an important limitation, when compared to other domestic species, mainly in the in vitro fertilization (IVF) stage, where the results are limited and its efficiency is still being tested, being the injection intracytoplasmic spermatozoa (ICSI) the biotechnology of choice. Thus, the present work aims at ways to increase the efficiency of the technique with a focus on follicular aspiration. The oocytes were separated into groups according to the size of the aspirated follicle (group 1: <10mm; group 2: 10-20mm; group 3: 20-30mm; group 4: >30mm) and were submitted to all ICSI processes until embryonic evaluation pre transfer. The oocyte recovery rate was 68.8% for group 1, 57.69% for group 2, 66.6% for group 3 and 0 for group 4. The best maturation rate was for group 3 (100%) and group 1 had degenerated and immature in greater quantity (42.5%). The evaluation of cleaved and transferable embryos had better results with oocytes from group 3, but the low “n” hampered the precision of the findings.