• Journal of Embryo Transfer
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• v.18 no.3
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• pp.257-262
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• 2003

These studies were performed to improve the reproductive efficiency of gilts and we investigated the effects of nursing periods after parturition and backfat thickness will adapt to these results for early selection of excellent gilts. The main results were as follows; 1. The backfat thickness in sows nursing for 17∼21 days was 19.19 mm, and 16.52 mm in 22∼26 days and longer nursing period affected significantly the backfat thinner (p<0.01). 2. The recurrence of estrus in sows nursing for 17∼21 days was 5.76 day and 5.62 day in 22∼26 days and there was no difference between nursing periods. 3. The recurrence of estrus in sows had 13∼16 mm backfat thickness was 5.69 day, 5.67 day in 17∼20 mm and 5.75 day in 21∼23 mm and there was no difference among backfat thickness. 4. The concentration of plasma estradiol were 28.49 pg/$m\ell$ in parturition, 12.39 pg/$m\ell$ in weaning and 16.52 pg/$m\ell$ in return of estrous. The concentration ot plasma progesterone were 1.50 ng/$m\ell$ in parturition, 0.69 ng/$m\ell$ in weaning and 0.94 ng/$m\ell$ in return of estrous. The concentration of plasma cortisol were 57.74 ng/$m\ell$ in parturition, 43.01 ng/$m\ell$ in weaning and 47.89 ng/$m\ell$ in return of estrous. There showed the highest level of estradiol, progesterone and cortisol in parturition.

• Journal of Embryo Transfer
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• v.28 no.1
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• pp.7-12
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• 2013

Body condition score (BCS) is a useful management tool for distinguishing differences in nutritional needs of cows in the herd. Although it is not always possible to quantify the nutrient content of the feed supplied to the donor cow, the nutritional status can be determined by the BCS. The objective of this study was to evaluate in vivo embryo production, return to estrous of donor and pregnancy rate of recipients following BCS in Hanwoo superovulation. Sixty nine Hanwoo donor cows were flushed on day 7 of estrus cycle with same FSH and artificial insemination by the same technicians. Embryos were recovered on 7 days after the third insemination by flushing the uterus with Embryo Collection Medium. The results obtained were as follows: No differences were observed in the efficiency of superovulation rates regardless of BCS ($${\leq_-}2.0$$, 2.5 to 3.0, and $${\geq_-}3.5$$). The mean number of total embryos was each $5.20{\pm}0.86$, $11.56{\pm}1.04$, and $6.23{\pm}1.07$. The mean number of transferable embryo from $${\leq_-}2.0$$, 2.5 to 3.0, and $${\geq_-}3.5$$ of BCS was $2.60{\pm}0.87$, $7.94{\pm}0.89$, and $4.75{\pm}1.32$, respectively (p<0.05). Return to estrous regardless of donor BCS was no difference. The pregnancy rates of recipient were BCS $${\leq_-}2.0$$ 11.76%, 2.5 to 3.0 40.79%, and $${\geq_-}3.5$$ 11.11%, following transfer of fresh embryos produced in vivo, respectively. These results indicate that if the Hanwoo with BCS 2.5 to 3.3 are used for donor and recipient, the embryo production and the conception rate will be greater.

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.201-205
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• 2010

The objective of this study was investigate the superovulation treatment and to relate concentrations of blood urea nitrogen(BUN) in Hanwoo donors. Thirty six, at random stages of the estrous cycle, received a CIDR. Four days later, the animals were superovulated with a total of 28AU FSH (Antorin, 2AU=1 ml) administered twice daily in constant doses over 4 days. On the 3th administration of FSH, CIDR was withdrawn and 25 mg $PGF_2a$ was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received $100\;{\mu}g$ GnRH at the time of 1st insemination. Embryos were recovered 7 or 8 days after the 1st insemination. Cows with BUN <10, 11~18 and ${\geq}$19 mg/dl had return of estrus of 34.6, 30.5 and 30.4 days respectively. Return of estrus after superovulation treatment was not significantly lower for cows with blood urea nitrogen (BUN) above 10 mg/dl than for cows with BUN below 10 mg/dl. Cows with BUN <10, 11~18 and ${\geq}$19 mg/dl had number of transferable embryos of $3.2{\pm}1.2$, $5.4{\pm}1.9$ and $4.1{\pm}2.1$ respectively.

• Korean Journal of Veterinary Research
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• v.27 no.1
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• pp.137-140
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• 1987

Information on certain reproductive traits were obtained from field material. The data for this study were taken from 1,111 breeding records of 273 cows and 193 heifers at Koheung, Chonnam, during the period 1979 to 1984. The cattle were bred by artificial insemination; only one or two cattle were reared by one farmer. The heifers were first bred at 551.75 days after they were born; they were pregnant at 569.06 days after birth. The average estrous cycle length was 21 days; the average number of inseminations per conception was 1.56. The non-return rate for first inseminations for cows and heifers was 62.5% and 59.6%, respectively. The gestation length was 285.79 days. Of 1,111 viable calved born 582 were male, giving a sex ratio of 100:110. The average length between calving and first insemination was 88.9 days; average calving interval was 397.69 days.