Beef marbling is known as one of the most important beef-quality traits in Korea. It is likely that marbling derived from fatty acids, mainly propionate, is mediated by rumen. Recently micro-agents were studied to enhance marbling, although many parts of that were digested in rumen. Therefore, this study was conducted to screen candidate materials to effect on beef quality with in vitro ruminal incubation. The materials such as saponin, chitosan, Zn compounds (4), vitamin C sources (2), Korean herb cocktail and garlic sources (2) were added to rumen fluid to 1.25% of substrate volume at 0 and 24 h incubation time. Total gas production in intact vitamin C source increased but that in all Zn compounds decreased (P＜0.05). Total gas production in Zn sulfate compound less decreased than in other Zn sources. Propionate in Zn sulfate increased than the other candidate compounds at all incubation time (P＜0.05). Experiment two was conducted to clarified effect of additives such as vitamin C sources (2), garlic lyophilized, Korea herb cocktail and Zn sulfate were supplemented with 2.5% volume at the 0, 3, 6, 12 and 24 h incubation time. Total gas in Zn sulfate was lower than any other treatments. Propionate in garlic, herb and Zn sulfate appeared to be lower than control and vitamin C sources at all incubation time, although significant difference was not observed in total VFA among control and all treatment. This study suggested that micro-agent might be used to improve beef quality with minute level.

An in vitro study was conducted to investigate the effect of propionate precursor (malate or fumarate) on fermentation characteristics, production of conjugated linoleic acid (CLA) and methane (CH₄) by rumen microbes when incubated with linoleic acid (C18:2) as a CLA precursor. Total CH₄ production for 12h incubation, however, was greatly reduced (P＜0.0001) by all the supplements compared to that of control, and its production from M-LA or F-LA treatment was smaller than that from LA treatment. Supplementation of M-LA or F-LA also increased concentrations of cis9, trans11-CLA (P＜0.039 - P＜0.001) for all incubation times and trans10,cis 12-CLA at 1h (P＜0.013), 3h(P＜0.036) and 12h (P＜0.025) incubation times compared to LA supplementation.

We measured the non-carbon content of single-walled carbon nanotubes (SWCNTs) in SWCNT soot using thermogravimetric analysis. The weight increased percentage by the oxidation of metal in the raw soot is well obtained by TGA graph which was confirmed with ICP-AES, XRD, and XPS. This work will be very useful for the purity precise evaluation of SWCNT with UN-vis-NIR spectroscopy.

This study was conducted to investigate the effects of type of the sugar supplemented to the extender on the vigor, viability and intact acrosomal rates of frozen-thawed dog spermatozoa. The ejaculated semen was diluted with TRIS-citric acid extender containing 200mM TRIS, 73mM citric acid, 6% (v/v) glycerol, 20% (v/v) egg yolk, 1% (v/v) antibiotics (streptomycin/penicillin), 44 mM sugar, which was either glucose, fructose or glucose-fructose combination, and distilled water to make the final volume of 100ml. Extended semen samples were cooled at for an hour, packaged in 0.25ml straws, equilibrated for 10 minutes in liquid nitrogen vapor, and frozen in liquid nitrogen. Samples were thawed by placing straws into water for 120 seconds. After thawing, vigor, viability and intact acrosomal rates of frozen-thawed semen were compared according to type of sugar. No significant differences were observed between glucose and fructose groups. In addition, combination of the 2 sugars also did not show any significant differences in the vigor, viability and intact acrosomal rates. In conclusion, glucose and fructose were equally efficient as sugar supplements for freezing extender.