• Journal of Embryo Transfer
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• v.17 no.3
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• pp.235-238
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• 2002

The present study was undertaken to find out possibilities for superovulation and recovery of freezable/transferable embryo from repeat breeding crossbred cows. For this study a total of 10 Holstein crossbred cows having history of failure of conception even after more than 4~5inseminations were taken and superovulated using Folltropin-V at 100 to 140% dose schedule. The results indicated that out of 10 donors, 8 responded to superovulatory treatment and yielding a total of 94 embryos, out of which 45 were of transferable/freezable quality. The mean ovulations and mean transferable embryos were 11.5$\pm$2.91 and 4.5$\pm$1.66, respectively. These observations suggests that the repeat breeding cows having conception failure after several artificial inseminations can be used as donors for production of embryos and calves through embryo transfer technology.

• Journal of Embryo Transfer
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• v.24 no.1
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• pp.47-55
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• 2009

This study was performed to investigate the possibility of repeated superovulation treatment at interval from 27 days to 41 days in Hanwoo cattle and to compare with superovulation effect between doses of FSH 200 mg and FSH 400 mg. Different doses of FSH (200 mg or 400 mg) were injected at Day 8 after controlled internal drug release (CIDR) treatment for superovulation of Hanwoo donors following CIDR treatment (Day 8 after the estrus). Superovulation was repeated four times for one donor and number of corpus luteum (CL), number of embryos, number of transferable embryos and pregnancy rate after embryo transfer (ET) were investigated. 5 cows were used for each FSH treatment (10 cows in total). Average number of CL were $10.16{\pm}3.85$ and $11.56{\pm}2.35$ for the donors treated with FSH 200mg and FSH 400mg, respectively. Average number of embryos collected were $8.85{\pm}4.05$ and $8.30{\pm}1.73$ for the donors treated with FSH 200 mg and FSH 400 mg, respectively. Average number of transferable embryos were $5.48{\pm}2.45$ and $4.58{\pm}2.23$ for the donors treated with FSH 200 mg and FSH 400 mg, respectively. The pregnancy rate following ET with embryos collected from 200 mg FSH treated donors and 400 mg FSH treated donors were 61.9% and 53.8% respectively. The numbers of embryos tended to be decreased as the numbers of repeat of superovulation were elapsed. These results indicated that superovulation treatment by about a month to Hanwoo donors is usable and 200 mg of FSH is preferable for simple FSH treatment following CIDR treatment.