Matrix Metalloproteinases (MMP)-2 and -9 are participated in embryo development, implantation, remodeling of epithelial cell and ovulation. The objective of this study is to evaluate an impact of MMP2 and MMP9 on embryonic developmental competence as well as gene expression profiles of in vitro-produced bovine embryos. After in vitro fertilization, embryos of all groups were transferred into IVC-2 medium treated with MMP2 and MMP9 to check the optimum concentration on the basis of embryo development competence and cell numbers. The optimum concentrations for MMP2 and 9 were 1,200 ng/ml and 300 ng/ml. The blastocyst development competence was not different among 1,200 ng/ml of MMP2 vs. 300 ng/ml of MMP9 vs. combined MMP2 + 9 vs. control groups (41.46 ± 10.66 vs. 37.73 ± 8.92 vs. 45.11 ± 11.41% vs. 41.59 ± 11.88, respectively). Furthermore, the developmental competences to hatching and hatched blastocysts were not also different among the same groups (79.84 ± 12.63 vs. 83.3 ± 17.46 vs. 78.55 ± 14.48% vs. 72.02 ± 14.09). In addition, total cell number was significantly (p<0.05) greater in blastocyst treated with MMP9 300 ng/ml among all treatment groups. On the other hand, there was no significant difference of ICM vs. TE ratio in all groups. The expression of five out of six genes (i.e., MMP2, MMP9, IFNt, SSLP1 and HNRNPA2B1) was different among the groups. The expression of IFNt and HNRNPA2B1 genes was significantly greater in MMP9 (p<0.05), but there was no difference of MMP9 expression between MMP2 and MMP9 group (p>0.05). The normalized expression of MMP2 and SSLP1 was greater in MMP2 than other groups (p<0.05). In conclusion, MMPs treatment during IVC-2 medium was remarkably effected on blastocyst developmental competence and gene expression profiles that are related to embryo quality and implantation.

The present research was carried out to evaluate the possibility of increasing female offspring production ratios using artificial insemination buffer (AIB) before artificial insemination (AI). In this experiment, we optimized AIB composition, made an AIB gun and analyze factors affecting AI non-return rate after AIB treatment. The AIB was made with the base of Tris-buffer supplemented with L-arginine and several other chemicals that might reduce the motility of male sperm compared to the female counterpart, therefore, increasing the possibility of fertilization by female sperm. AIB must be deposited into to cervix by AIB gun. After 15 min of AIB deposition, frozen semen was deposited into the same place. A total of 348 cattle were inseminated with AIB insemination, and there were no significant differences between AIB and traditional AI non-return rates (56.8% vs. 55.7%). The AI non-return rate in AIB group, however, differed significantly among 7 Hanwoo farms. The parturition numbers ( to ) of cows did not affect AIB AI rate. The proportion of AIB AI success rates was significantly higher in Hanwoo cows than in dairy cows (61.0% vs. 48.7%), but the average AI success rate did not differ significantly between AIB and conventional AI (56.8% vs. 55.7%). The female offspring production rate in to cervix deposition place was significantly higher than that in the uterus body (77.7% vs. 59.6%, p<0.05). The injection volume of AIB in 5 and 10 ml was significantly higher than that in 2 ml (77.7%, 78.7% vs. 51.8%, p<0.05), but there were no differences in AIB injection volume between 5 and 10 ml. The best exposure time of AIB in the cervix was 10 to 15 min rather than 5 min (79.2%, 77.2% vs. 52.6%, p<0.05). AIB therefore needs to have an exposure time of at least over 10 min for a higher production rate of female offspring. In conclusion, AIB could be used in AI industry to increase the female offspring ratio and AIB AI can increase the AI success rate.