The purpose of this study was to determine the effect of different feeding ratios of whole crop barley silage on the embryo production in Hanwoo donors. All donors were basically fed 2.5 kg concentrate daily. Donors were divided into three groups according to the different feeding of forage; hay 70% and rice straw 30% (control, n = 21), whole crop barley silage 80% and rice straw 20% (T1, n = 25), and whole crop barley silage 60% and rice straw 40% (T2, n = 23) fed based on TDN 6.70/ BW 500 kg. All Hanwoo donors received a CIDR together with injections of 1 mg estradiol benzoate and 50 mg progesterone (, Day 0). Four days later, they were superovulated with 28 mg FSH twice daily IM in decreasing doses over 4 days. Then donors received 2 doses of (25 and 15 mg) with the 5th and 6th injections of FSH on Day 6. CIDR were withdrawn at the 6th FSH injection and the donors received GnRH 36 h after the second injection. The donors were artificially inseminated twice, at 8 and 24 h after GnRH, and embryos were recovered 7 or 8 days after the 1st insemination. The flush rate of the donors following positive superovulation responses did not differ among groups (76.2~96.0%, p>0.05). The number of corpus luteum (CL) at embryo recovery also did not differ among groups (10.6~14.0, p>0.05). Furthermore, the mean numbers of total ova (9.4, 10.5 and 12.0) and transferable embryos (5.3, 12.0 and 6.5) did not significantly differ among the control, T1 and T2 groups, respectively (p>0.05). However, mean concentrations of serum of the T1 (64.2 ng/ml) and T2 groups (55.7 ng/ml) were higher than that of control group (43.3 ng/ml, p<0.01), while serum cholesterol concentrations in the control (105.8 mg/dl) and T2 groups () were significantly lower than in the T1 group (121.1 mg/dl, p<0.05). Conclusively, whole crop barley silage can be fed a good substitute for hay forage for Hanwoo donors. Furthermore the ratios of whole crop barley silage 60% and rice straw 40% might be more worthful for embryo production.

The aim of present experiment was to examine hatching rate as in vitro indicator of viability of porcine embryos before early stage embryo transfer such as zygotes or 2-cell stage embryos. Cumulus-oocyte complexes (COCs) collected from ovaries were matured in North Carolina State University 23 (NCSU-23) containing 10% porcine follicular fluid (pFF), 10 ng/ml epidermal growth factor (EGF), follicle stimulating hormone (FSH), luteinizing hormone (LH), and 1mg/ml cysteine. After 24 hours, the COCs were transferred to the same medium without hormones. After 65h of maturation, oocytes were exposed to phosphate buffered saline (PBS) with 7% ethanol (v/v) for 7 minutes, and then the oocytes were washed and cultured in tissue culture medium (TCM) 199 containing 5 ug/ml cytochalasin B for 5h at in an atmosphere of 5% and 95% air with high humidity. After cytochalasin B treatment, the presumptive parthenotes were cultured in porcine zygote medium (PZM)-5 and cleavage of the parthenotes was assessed at 72h of activation, Normally cleaved parthenotes were cultured for an additional 8 days to evaluate their ability to develop to blastocyst and hatching stages. The fetal bovine serum (FBS) were added at Day 4 or 5 with concentrations of 2.5, 5 or 10%. The blastocyst rates were ranged within in each treatment. However hatching rate was dramatically decreased in non-addition group. In this experiment, embryo viability in female reproductive tract may be estimated before embryo transfer with in vitro culture adding FBS by hatching ability.