Possibilities for improving the quality of sheep embryos produced in vitro

The main hypothesis of this Ph.D. thesis suggests overcoming the shortcomings of in vitro embryo production in sheep, and six experiments were performed on this basis. The first experiment dealt with the impact of transport media on ovarian tissues in addition to the effect of temperature and the medium of ovarian transport on the development of embryos. The histomorphology of the ovary showed that in AUZ1, the follicles were better maintained, and a temperature of 2 to 4 °C significantly increased embryonic development rates. The second experiment aimed to design new strategies of capacitation by starving a ram's sperm and estimating its quality effects. The sperm were hyperactive and showed a significant increase in the ability to fertilize oocytes in the sperm starvation protocol. The third experiment investigated the effectiveness of antioxidants in the appropriate capacitation of the sperm and fertilization media. Sperms treated with melatonin demonstrated hyperactivity, and the fertilization rate was significantly increased. The fourth experiment aimed to estimate the extent to which the development of embryos is affected by shortening the time of In Vitro Fertilization (IVF) and showed that exposing gametes to IVF for 6 h results in a higher fertilization rate and an improvement in the quality of embryo development. The fifth experiment, which compared the traditional and SAGE media, showed that SAGE significantly affected embryonic development. Ultimately, the sixth experiment examined the extent to which embryonic development was affected by the breed from which the oocytes were taken and did not find any significant difference between breeds. In general, our findings highlight several crucial aspects of obtaining high-quality embryos and high embryonic development rates.