This study was designed to compare the efficiency of the Cryotop method and that of two methods that employ a micro volume air cooling (MVAC) device by analyzing the survival and development of bovine oocytes and blastocysts vitrified using each method. In experiment I, in vitro-matured (IVM) oocytes were vitrified using an MVAC device without direct contact with liquid nitrogen (LN2; MVAC group) or directly plunged into LN2 (MVAC in LN2 group). A third group of IVM oocytes was vitrified using a Cryotop device (Cryotop group). After warming, vitrified oocytes were fertilized in vitro. There were no significant differences in cleavage and blastocyst formation rates among the three vitrified groups, with the rates ranging from 53.1% to 56.6% and 20.0% to 25.5%, respectively; however, the rates were significantly lower (P < 0.05) than those of the fresh control group (89.3% and 43.3%, respectively) and the solution control group (87.3% and 42.0%, respectively). In experiment II, in vitro-produced (IVP) expanded blastocysts were vitrified using the MVAC, MVAC in LN2 and Cryotop methods, warmed and cultured for survival analysis and then compared with the solution control group. The rate of development of vitrified-warmed expanded blastocysts to the hatched blastocyst stage after 24 h of culture was lower in the MVAC in LN2 group than in the solution control group; however, after 48–72 h of culture, the rates did not significantly differ between the groups. These results indicate that the MVAC method without direct LN2 contact is as effective as the standard Cryotop method for vitrification of bovine IVM oocytes and IVP expanded blastocysts.

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Generally, laparoscopic intrauterine insemination (LII) provides a higher success rate than that of cervical insemination in goat. However, the sperm distribution following LII in goat remains unknown, especially when frozen semen is used. This study aimed to evaluate the distribution of frozen-thawed goat sperm after LII. In experiment 1, the frozen-thawed sperm were stained with CellTrackerTM Green CMFDA (CT-Green) or CellTrackerTM Red CMPTX (CT-Red), and then evaluated in vitro for viability and motility at 0, 3, 6, and 9 h after staining. In experiment 2, the CT-Green and CT-Red labelled sperm (30 × 106 sperm in 0.125 mL in each side) were laparoscopicaly inseminated into the left and right uterine horns, respectively (n = 4). After ovariohysterectomy at 6 h post-insemination, the distributions of green and red coloured sperm were assessed by tissue section and sperm flushing. The comparison of semen parameters among groups (control, CT-Green, and CT-Red) were statistically analysed by a general linear model. The results revealed that the fluorochromes used in this study did not impair the sperm motility and viability (P > 0.05). The frozen-thawed goat sperm transuterine-migrated following LII, as both CT-Green (left insemination) and CT-Red labelled sperm (right insemination) were found in both sides of the reproductive tracts. This study concludes that LII in goat would be simpler and consume less time if the semen was unilaterally deposited. Supported by a grant from Chulalongkorn University Centenary Academic Development Project and RGJ-PhD-industrial link program, Thailand Research Fund (PHD/0156/2550).