Glucose is universal and essential fuel of energy metabolism and in the synthesis pathways of all mammalian cells. Glucose is the one of the major precursors of lactose synthesis using glycolysis result in producing milk fat and protein. During the milk fat synthesis, lipoprotein lipase (LPL) and CD36 are required for glucose uptake. Various morecules such as acyl-CoA synthetase 1 (ACSL1) activity of acetyl-CoA synthetase 2 (ACSS2), ACACA, FASN AGPAT6, GPAM, LPIN1 are closely related with milk fat synthesis. Additionally, glucose plays a major role for synthesizing lactose. Activations of lactose synthesize enzymes such as membranebound enzyme, beta-1,4-galactosyl transferase (B4GALT), glucose-6-phosphate dehydrogenase (G6PD) are changed by concentration of glucose in blood resulting change of amount of lactose production. Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose over a plasma membrane. There are 2 types of glucose transporters which consisted facilitative glucose transporters (GLUT); and sodium-dependent transport, mediated by the Na+/glucose cotransporters (SGLT). Among them, GLUT1, GLUT8, GLUT12, SGLT1, SGLT2 are main glucose transporters which involved in mammary gland development and milk synthesis. However, more studies are required for revealing clear mechanism and function of other unknown genes and transporters. Therefore, understanding of the mechanisms of glucose usage and its regulation in mammary gland is very essential for enhancing the glucose utilization in the mammary gland and improving dairy productivity and efficiency.

The aim of this study was to evaluate the changes of protein patterns in granulosa cells and corpus luteum in ovaries during the estrus cycle in cows. The estrus cycle was devided into five steps of follicular, ovulatory, early-luteal, mid-luteal and late-luteal phases. In results, 61 spots of total 85 spots were repeated on follicular phase and 51 spots of total 114 spots were repeated on ovulatory phase. The 40 spots of total 129 spots were repeated on early-luteal phase and 49 spots of total 104 spots were repeated on mid-luteal phase. Also 41 spots of total 60 spots were repeated on late-luteal phase. On the other hands, the 16 spots were indicated difference in follicular phase and ovulation phase had a difference 10 spots. It was showed difference No. 103 spot in ovulation phase, No. 135 spot in early-luteal phase and No. 175 and 176 spots in mid-luteal phase. Also, the 11 spots were expressed specifically in mid-luteal phase and No. 178 and 179 spots were difference of expression in late-luteal phase. We confirmed that there were 7 spots for ovulation, 4 spots for luteinization and 2 spots for luteolysis. Spot No. 89～93 in ovulation phase were transferrin, and spot No.94～98 were HSP60. Spot No. 103 was Dusty PK, spot No. 135 was OGDC- E2, and spot No. 175 and 176 were Rab GDI beta from luteinization. Spot No. 178 and 179 in luteolysis were vimentin. This results suggest that will be help to basic data about infertility.

The objective of this study was to evaluate several types of uterine bacteria in Hanwoo. uterine bacteria from randomly selected 5 uterus was collected by flushing methods into a sterilized 1.5 ml centrifuge tube and was inoculated onto MacConkey agar and blood agar, respectively. After being incubated for 5% CO2, aerobic or anaerobic condition at 37℃ during 48h, bacterial colonies were selected and re-inoculated onto blood agar plates. Re-cultured colonies were identified by Gram staining and finally identified using Vitek system. The identified bacteria were Staphylococcus lentus, Staphylococcus sciuri, Staphylococcus vitulinus, Staphylococcus warneri of Gram (+) and Rhizobium radiobacter, Sphingomonas paucimobilis of Gram () bacteria. Although, pathogenicity of identified bacteria was unclear, the bacteria can have an effect on the uterine microenvironment. Therefore, repetitive research will be required to determine the effects of bacteria in cattle exposed to a various environment.

This study evaluated a sexed sperm ability to produce embryos by flow cytometer. Hanwoo bulls sperm were separated to X and Y sperm via Hoechst 33342 stained with near UV laser or performed the pre-sorted without near UV laser beam in flow cytometry. Pre-sorted sperm had significantly higher viability (84±1.15 %, p<0.05) compared to other sorted groups in frozen-thawed semen. For fresh semen, pre-sorted sperm had the higher viability (79±3 %, p<0.05) than those of the X and Y sperm (44.7±1.67 and 41.7±1.2 %) separated by differences of DNA content. On the other hand, pre-sorted and X sperm sorted according to differences in DNA content had significantly higher viabilities (24.3±1.2 and 25.7±0.9 %, p<0.05) compared to that of the sorted Y sperm (13.7±1.2 %) in the hypoosmotic swelling test. The proportion acrosome reaction in the sorted X sperm was higher (55.0±1.7 and 45.0±1.5 %) than those of the sorted Y-sperm (32.3±0.9 %, p<0.05). However, the sperm morphologies of the sorted groups were not significantly differences. In conclusion, the sex-sorting procedure by flow cytometry affected some characteristics of Hanwoo sperm. Further study is needed to determine the optimal procedures to enhance male and female embryos and sorting accuracy.

This study was performed to investigate the FSH levels for superovulation procedure in Korean Native Cattle (Hanwoo). The effectiveness of 200 mg and 400 mg of FSH to initiate superovulation was examined in Hanwoo. Donors, at random stages of the estrous cycle, received a CIDR. 7 days later, 200 mg FSH group was treated with 40, 30, 20, 10 mg FSH levels in declining doses twice daily by intramuscular injection for 4 days. Also, 400 mg FSH group was treated with 80, 60, 40, 20 mg FSH levels. On the 3rd day administration of FSH, 25 mg PGF2α was administered and CIDR was withdrawn. Donors were artificially inseminated twice at 12 hr intervals. The donor cattle received 250 μg GnRH at time of 1st insemination and embryos were recovered 8 days after the 1st insemination. As a results, average number of CL treated with FSH 200 mg was higher as 20.9±1.20 than 15.8±0.63 for donors treated with FSH 400 mg, respectively(p<0.05). Treated group of 200 mg FSH level increased (p<0.05) the number of embryos recovered per procedure compared to 400 mg FSH level (18.2±1.18 vs. 12.38±0.52, respectively). When treatment of 200 mg FSH was performed, average transferable embryos/ova increased (p<0.05) to 14.1±1.12 from 6.8±0.33 of treated of 400 mg FSH. Group of 200 mg FSH increased (p<0.05) to 8.3±0.76 from 2.0±0.26 in morula stage compare to 400 mg FSH group. Mean of total early blastocyst and expanded blastocyst stage embryos was similar (p<0.05) between the 200 mg and 400 mg FSH levels group (4.7±1.19 vs. 2.9±0.18 and 1.2±0.40 vs. 1.9±0.17). These results suggest that 200 mg FSH level-based superovulation protocol with CIDR may be effectively used for production of superior embryos in Hanwoo. In other words, the less level of FSH may be effectively applied for Hanwoo (Korean Native Cattle), because Hanwoo was smaller body size than beef or daily cow.