The current study was conducted to investigate effects of sera taken from Hanwoo at different age on adipocyte differentiation. Sera were taken from Korean native (Hanwoo) steers at 6, 12, 18, and 24 months of age, respectively and supplemented to 3T3-L1 preadipocytes after the cells reached confluence and maintained 10 days thereafter. For the first 2 days (48 h), cells were induced to differentiate by addition of differentiation factors, methylisobutylxanthine, daxamethasone, and insulin. After the differentiation, the cells were incubated without differentiation factors except insulin. The cells lost their fibroblastic shape and showed round-up appearances after 10 days incubation with FBS and the sera of Hanwoo steers. Big lipid droplets appeared in the cells cultured with FBS and the sera taken from Hanwoo at 18 and 24 months of age. After 18 months of age, GPDH activity was statistically higher than 6 and/or 12 months of age (P < 0.05). Based on morphology and Sn-glycerol-3-phosphate dehydrogenase activities, Hanwoo steers expressed aged-dependent adipogenic activities, indicating that aged sera may result in high adipocyte differentiation. It is concluded that the 18 months of age may be ‘threshold’ to express major adipogenic activities. This may strongly support previous field studies reporting considerable increase in fat contents of Hanwoo carcass at over 18 months of age.

Effects of pretreatment and extraction conditions on total polyphenol yield from licorice root were investigated using statistical method. For pretreatment, heat treatment at 121°C for 10 min was applied. Licorice root content in solvent (10, 20, and 30%) ethanol concentration (20, 40, and 60%) and reaction time (1, 2, and 3 h) were used as variables for extraction conditions. Two experiments, with heat treated and no treated licorice, were prepared with same experimental design. Box behnken design was employed and produced a total of 15 trials. Total polyphenol yield from licorice root was not affected by heat treatment. Among variables, licorice content in solvent showed most significant effect regardless of other variables (p

Rumen fermentative characteristic is useful indicators of the quality of ruminant feed stuffs and diets. An in vitro rumen fermentation experiment was therefore carried out to compare fermentation patterns among three forage sources. These were whole crop barley (WCBS), Italian ryegrass silage (IRGS) and rice straw silages (RSS). Rice straw (RS) was the control, making the treatments 4 in total. Forages were randomly allocated to serum bottles. The incubation times were arranged 0, 3, 6, 9, 12, 24, 48 and 72h at 39℃, respectively. Each forage source was replicated 3 times per incubation time. At each sampling time, total gas and pH were measured, whilst individual volatile fatty acids (VFAs), total volatile fatty acids (TVFAs) and ammonia nitrogen (NH3-N) were determined later after storing samples at -20℃. Acetate: Propionate ratio (A/P) was then calculated. Forage source had a significant effect (P