The effect of exogenous melatonin administration before superovulation on embryo yield in Assaf ewes.

The aim of this study was to determine the effect of exogenous melatonin administration on transferable embryos by increasing total antioxidant status before superovulation in Assaf ewes. Selected ewes were randomly divided into two equal groups: melatonin (n = 9) and control (n = 9). In the melatonin group, a melatonin implant (18 mg melatonin, Regulin®, Ceva, Turkey) was placed under the skin of the ear 7 days prior to insertion of the progesterone-containing sponge. In the control group, a physiological saline solution was injected under the skin of the ear on the same day. The same superovulation protocol was used in both groups. In addition, blood samples for determination of Glutathione peroxidase, superoxide dismutase, total antioxidant status and total oxidant status concentrations were collected on five different days, including the day of melatonin implant placement (Day-7), vaginal sponge insertion (Day 0), vaginal sponge removal (Day 11), mating (Day 12-13) and uterine flushing (Day 19). Embryos were collected by laparotomy on the 7th day after mating. Uterine flushing taken into petri dishes were scanned under a stereomicroscope, and the quality and developmental stages of the embryos were recorded. In the study, total corpus luteum count and total cell count were found to be higher in the control group than in the melatonin group (p < .05). When the results were evaluated in terms of oxidative stress index, a negative correlation was found between the total number of corpus luteum, number of cells obtained, count of transferable embryos and number of Grade 1 embryos on Day 0. There was also a positive correlation oxidative stress index and the number of unfertilized oocytes on Day-7. As a result, exogenous melatonin administration prior to superovulation during the breeding season is thought to have a negative effect on embryo yield and quality. Therefore, the use of exogenous melatonin in MOET studies during the breeding season is recommended to be investigated in new studies.

Does using microfluidic sperm sorting chips in bovine IVEP affect blastocyst development?

This study aimed to determine the effect of microfluidic sperm sorting chip on embryo development and quality in the sperm treatment step in in vitro embryo production in cattle. Only A-quality oocytes obtained from the ovaries of Holstein cattle were included in the study. These oocytes were first placed in in vitro maturation medium, and matured oocytes were randomly divided into two groups at the 24th hour of maturation. Oocytes in the first group with the Microfluidic Sperm Sorting Chip (MFSC, n = 154) were put into a fertilization medium with spermatozoa prepared with microfluidic sperm sorting device. Oocytes in the second group (Con, n = 169) were fertilized with spermatozoa prepared by the routine sperm treatment step of the commercial company. The rate of cleavage (85.71% vs. 76.33%, respectively) and of reaching the blastocyst (44.15% vs. 32.54%, respectively) in the MFSC group were higher than the control group. In addition, it was determined that the numbers of ICM (45.8 ± 2.04 vs. 39.2 ± 1.85, respectively), TE (122.13 ± 2.19 vs. 115.0 ± 2.61, respectively), TC (167.93 ± 2.89 vs. 154.2 ± 2.62, respectively) increased in the MFSC group compared to the control group. A statistically significant difference was found in the number of cells with apoptosis per embryo (5.14 ± 0.77 vs. 11.91 ± 0.79) and apoptotic index rates (3.06 ± 0.47 vs. 7.72 ± 0.55%) of the MFSC and Con groups. As a result, we concluded that using microfluidic sperm sorting chips during sperm treatment in bovine IVEP increases the rate of reaching the blastocyst, embryo development, and quality and reduces the possibility of apoptosis in developing blastocysts. For this reason, it is also thought that the use of microfluidic sperm sorting devices during sperm treatment in bovine IVEP may be a new alternative in this field.