Effects of PEG on Embryo Production in Superovulated Hostein Cows

This study was conducted to improve the efficiency of embryo recovery and to establish the protocols of superovulation in Holstein cows. Sixteen Holstein cows were used the test the efficacy of three superovulation regimens using Folltropin. In the case of regimen 1, CIDR plus with E2 capsule was inserted in cows at the random stage of estrous cycle and the total of 400 mg Folltropin V was adminstered twice a day for 4 days(Folltropin V group). In regimen 2, CIDR was inserted and 3.0 mg estradiol benzoate was administered i.m. next day and the total of 400 mg Folltropin was adminstered twice a day for 4 days(Folltropin V+EB group). For regimen 3, CIDR insertion was same as in the regimen 2 and the total of 400 mg Folltropin diluted with $10\%$ PEG 8,000 was administered once(Folttropin V+PEG 8,000 group). In all the regimens, CIDR were removed on 12th day and 45 mg dinoprost was administered i.m. simultaneously. The heat detected donors were administered 200 ug LH-RH and inseminated twice with 2 straws of frozen semen 12 hours apart. Embryo were collected using Foley catherter in each uterine homs on 6${\~}$8 days after inseminations. The evaluation of collected embryos were according to the IETS manual. The CL responses according to the superovulation treatments were 5.8, 20.6, 24.0 in the Folltropin V, Folltropin+EB and Folltropin V+PE 8,000 groups, respectively and there were significant different among the treatments(p<0.01). Transferable embyos collected were 3.6$\pm$2.4, 3.3$\pm$l.8 and 2.8$\pm$2.3, in the Folltropin V, Folltropin+EB and Folltropin V+PE 8,000 groups, respectively. Degenerated and unfertilized embryos in regimen 2 and 3 than regimen 1. These results indicates that superovulation treatments with both multiple injections and a single injection using PEG of Folltropin combined with CIDR insertion at the random stage of estrus cycle can be used to produce Holstein embryos.

젖소 과배란 처리시 PEG(Polyethylene Glycol) 처리가 수정란 생산에 미치는 영향

본 연구는 젖소에 있어서 다량의 수정란을 생산하여, 고능력의 유전인자를 조기에 확산할 수 있도록, 젖소에 있어서 PEG를 이용하여 과배란 처리기법 확립을 위해 실시하였으며, 그 결과는 다음과 같다. 1. 성선자극호르몬의 처리 방법에 따른 황체반응은 Folltropin 단독처리시 $5.8\%$, Folltropin+EB는 $20.6\%$, Folltropin+PEG는 $24.0\%$로 나타났으며, 유의적인 차이를 보였다(p<0.01). 2. 성선자극호르몬의 처리 방법에 따른 이식 가능 수정란 수에 미치는 영향은 Folltropin V 단독처리시 3.6개, Folltropin +EB 처리시 3.3개, Folltropin +PEG 8,000 처리시 2.8개이었으며, 유의적인 차이를 나타내지 않았다(p<0.01). 3. 성선자극호르몬의 처리방법에 따른 퇴행란과 미수정 란 Folltropin+EB와 Folltropin+PEG 처리구에서 Folltropin 단독처리보다 많이 회수되었으며,배반포 수정란의 수에 있어서는 처리간에 유의적인 차이를 보이지 않았다. 이상의 결과는 임의의 발정주기에 CIDR 삽입후 Folltropin의 1일 2회 4일간의 분할 투여법 뿐만 아니라 Folltropin을 PEG로 용해하여 1회 투여법을 이용한 과배란 처리기법도 젖소 공란우에서 수정란의 생산이 가능함을 보여준다.