The increase in the total number of cows on farms, which breed Korean Native Cattle (KNC), is associated with many problems. In particular, the services per conception and calving interval have increased. In this study, we examined the effect of dietary supplementation with vitamin and mineral complex on the estrus rate, pregnancy rate, gestation length, and birth weight of KNC calves. Multiparous or primiparous KNC were divided into 3 groups with 40 heads per group. Experimental group 1 was administered a consisting of 35,000 IU vitamin A, 100 IU vitamin E, 200 mg -carotene, 200 mg Zn methionine, and 1.5 mg Se. Experimental group 2 was administered a vitamin complex (100 g/day) consisting of 100 IU vitamin E and 200 mg -carotene. In the case of multiparous KNC, the estrus detection rate in the control group was 90.0% and those in the experimental groups were 75.0% to 95.0%. However, the first-service pregnancy rate after parturition in the control group was 41.2%, which was significantly lower than that in the experimental groups (71.0% to 76.7%; p<0.05). The average duration of pregnancy in the group supplemented with the vitamin complex was days, which was similar to that in the case of the control group. The birth weight of calves from cows fed with vitamin complex was 25.3 to 27.0 kg, which was similar to that in the case of the control group (25.2 to 26.0 kg). In the case of primiparous KNC, no differences in the estrus rate, pregnancy rate, gestation length, or the birth weight of calves were noted between the groups. Thus, dietary supplementation vitamin and mineral complex have no effect on the reproductive efficiency in primiparous cows, but the pregnancy rate was observed to have increased in multiparous KNC with these supplements.

Salivary lipocalin (SAL1) is a member of the lipocalin protein family that has a property to associate with many lipophilic molecules and was identified as pheromone-binding protein in pigs. Our previous study has shown that SAL1 is expressed in the uterine endometrium in a cell type- and implantation stage-specific manner and secreted into the uterine lumen in pigs. However, function of SAL1 in the uterus during pregnancy in pigs is still not known. To understand physiological function of SAL1 in the uterine endometrium during pregnancy in pigs, it needs to elucidate the ligand(s) for SAL1. Thus, to identify the ligand for SAL1 in the porcine uterus, we collected uterine luminal fluid from pigs on day 12 of pregnancy by flushing with PBS. Proteins from the uterine luminal fluid were separated by ion exchange chromatography and gel filtration. Fractions containing SAL1 protein were pooled and concentrated. Immunoblot analysis confirmed successful purification of SAL1. Then, we extracted lipids from the purified SAL1 protein and analyzed the lipids by liquid chromatography-mass spectrometry, and predicted to be steroid hormones and prostaglandins as SAL1 ligands. Results in this study showed that SAL1 protein in the uterine secretions has a small lipophilic molecule as a natural ligand. Further characterization of ligand extracted from purified SAL1 will be useful for understanding physiological function of SAL1 during pregnancy and its application to increase the pregnancy rate in pigs.

This study was to investigate pregnancy rate of IVM/IVF/IVC Korean cattle (registered in government) embryos according to transport time course. For the production of embryos, oocytes recovered from slaughtered excellent grade cow and highly motile frozen‐thawed bull semen (purchased from LIMC, KPN#497) was used. In vitro produced embryos were cultured in CR1aa medium for 8 days and some of them were frozen. The rate of average cleavage (>2‐cell) was 83.0% (308/371) and blastocyst rate at day 8 was 34.7% (107/308). Among in vitro produced blastocyst embryos at day 8, most healthy embryos were freshly transferred on production day and some frozen embryos were direct transferred on appropriate day. These embryos were produced in a laboratory, embryo transfer (ET) was planned in 10 areas of the remote island (Jeju) from the laboratory by airplane. Thus, we examined the pregnancy rate in recipient cow according to embryo of transport time course before ET. From embryo transferred 44 recipient cows, overall pregnancy was 40.9% (18/44), these 18 cows were all calved [single, 94% (17/18); twin, 6% (1/18)] and total embryo implantation rate was 26% (19/66). Comparing transport time in the base of 6 hr, pregnancy rate in ET group required less 4 hr (60%, 9/15) was significantly higher than that required more 6 hr (26.3%, 5/19). In direct ET of freezing embryos, the pregnancy rate was 40% (4/10). However, it was difficult to find the meaning of temperature, pH and corpus luteum quality of recipients on comparison of pregnancy rate. When the cell death level of embryos according to storage time in thermos (straw container) before ET was measured by TUNEL staining, apoptotic index was increased with storage time‐dependent. These results demonstrated that long distance transfer of IVM/IVF/IVC embryos is possible and the time of embryo transport is very important for the pregnancy rate on field trial.

Lysophosphatidic acid (LPA), a simple phospholipid-derived mediator implicated in diverse biological actions, acts through the specific G-protein coupled receptors, LPA receptor (LPAR) 1～5. Our previous study showed that LPAR3 is expressed in the uterine endometrium in a cell type- and stage-specific manner and LPA via LPAR3 increases PTGS2 expression in the uterine endometrium during the period of implantation. Although LPAR3 is considered to be predominant LPA receptor in the uterine endometrium, other LPA receptors might play a role to mediate LPA functions in the uterine endometrium during pregnancy. Among LPARs, we investigated expression of LPAR1 during the estrous cycle and pregnancy in this study. Uterine endometrial tissue samples were collected from day (D) 12 and D15 of the estrous cycle and from D12, D15, D30, D60, D90 and D114 of pregnancy. Northern blot analysis determined that LPAR1 mRNA was constitutively expressed in the uterine endometrial tissues during the estrous cycle and pregnancy of all stages. Analysis by immunoblotting revealed that LPAR1 proteins were present in the porcine uterine endometrium during the estrous cycle and pregnancy. Immunohistochemical experiments demonstrated that LPAR1 protein was localized to endometrial epithelium and stromal cell, specifically to nuclei of these cell types. Results in this study show that LPAR1 is constitutively expressed in the uterine endometrium during the estrous cycle and pregnancy. These results suggest that LPA via LPAR1 may play a role in the uterine endometrial function throughout pregnancy in pigs.

This study was conducted to compare the expression pattern of the specific factors associated with pregnancy and angiogenesis during early pregnancy in Hanwoo. Synchronized female Hanwoo (4～6 year‐old) were inseminated artificially. After 10 weeks after artificial insemination (AI), the pregnancy was tested by rectal palpation method. Three pregnant and non‐pregnant Hanwoo were used in this experiment, respectively. The plasma progesterone level was measured by ELISA. Western blot analysis was performed to detect the expression of pregnancy associated glycoprotein (PAG) or angiogenic factors (VEGF, B‐FGF, ANP‐1, and TIE‐2). The plasma P4 level was increase gradually in pregnant group and maintained high level. The concentration of PAG was significantly higher from 5th weeks in pregnant group compared to that of non‐pregnant group (p<0.05). The concentrations of the VEGF (p<0.05), B‐FGF (p<0.05), and ANP‐1 (p<0.05) were significantly increased from 6th or 7th week after AI in pregnant group, respectively. And the intensity of TIE‐2, ANP‐1 receptor, was well matched with ANP‐1 (p<0.05). Taken together, it can be postulated that the blood vessels connected with fetus and dam were formed dramatically around 40 days after AI, because the expression levels of the angiogenic factors were increased significantly from this time in pregnant Hanwoo.