The objective of the present study was to evaluate the effect of disaccharides supplementation in glycerol-free tris (GFT) on dog sperm cryopreservation with respect to pH adjustment of extender and post-thaw incubation. The spermatozoa collected from five dogs were resuspended (5×107 cell/ml) with GFT containing 100 mM of lactose (L), trehalose (T) or sucrose (S) or pH adjusted (6.85) 100 mM of lactose (LP), trehalose (TP) or sucrose (SP). The sperm (500 μl) were loaded in straws, cooled for 50 min at 4℃, frozen using liquid nitrogen (LN2) vapor for 20 min and plunged in LN2. After thawing at 37℃ for 25 s in a water bath, the spermatozoa were incubated at 24℃ for 30 min. The progressive motility, viability, mitochondrial membrane potential (MMP) and mRNA expression of SMCP gene were then assessed. The MMP was evaluated by combined JC-1 plus PI staining. The relative abundance of SMCP was assessed using quantitative real-time polymerase chain reaction (RT-PCR). Adjustment of pH in GFT extender supplemented with disaccharides did not improve sperrm motility and viability. In general, post-thaw incubation increased the progressive motility of spermatozoa. The sperm motility in the group S was significantly (P<0.05) higher than other groups regardless of post-thaw incubation time. Similarly, the sperm viability in the group S was significantly (P<0.05) higher following post-thaw incubation. The higher sperm motility in the group S was also supported with the significantly (P<0.05) higher live sperm having high MMP. There was no significant difference in mRNA expression of SMCP gene among the experimental groups. These results indicate that cryopreservation of dog sperm in GFT supplemented with S and 30 min post-thaw incubation at 24℃ could provide better freezability of dog spermatozoa with improved motility and higher MMP.

Switchgrass is a wild-perennial plant in North America, and rich in cellulose, making it attractive as a source for cellulosic ethanol. Especially, ethanol which is made from switchgrass produce more 540% energy better than the others. The objectives of this study were to examine the concentrations of phenolic compounds, monosaccharides and disaccharides which detected in some different part (upper, center, lower) of 34 species of switchgrasses. The total average of phenolic compound concentration was 4017.48 ㎍/g. Whereas it's concentration in the upper part was shown the highest (6669.09㎍/g) and the lower part was the lowest (1916.30㎍/g). The No.23 has the highest concentration of phenolic compounds but No.20 have the lowest concentration. In saccharides analysis, only arabinose and glucose are detected. The total average of monosaccharides and disaccharides concentration was 206284.75 ㎍/g. Whereas its concentration in the upper part was shown the highest (269738.18㎍/g) and the lower part was the lowest (167567.53㎍/g). The No.30 has the highest concentration of saccharides but No.2 have the lowest concentration. The obtained results shows that switchgrass are good sources of bio-ethanol and the upper part is the best among them.