• Journal of Animal Science and Technology
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• v.46 no.1
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• pp.31-38
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• 2004

Data from five Hanwoo breeding farms were collected to analyze the effects of parity, season, nutrition and reproduction on body conditions of heifers and cows and to analyze the relationships of body conditions with reproductive performances and body growth. Analytic models included farms and parity which were run through SAS to estimate least squares means and correlation coeflicients between traits body condition scores(BCS) of I(very emaciated) through 9(very obese) scale at service and at calving. calving interval, days to rebreeding, gestation length. number of services per conception. Overall averages were 4.55 for BCS at service, 5.42 for BCS at calving. 406.7days of calving interval, 287.7days of gestation length, 66.2days from calving 10 first service and 1.78 times of services per conception. Number of services per conception was 1.50${\sim}$1.74 times for the cows of BCS 5 or under and 2.00${\sim}$3.00 for those of BCS 6 or higher. Body weight of calves from cows observed averaged 23.3kg at birth and 70.7kg at weaning. 57 percent of cows showed BCS 4${\sim}$5 at service while 46 percent of those showed 5${\sim}$6 at calving. Estimated phenotypic correlation coefficients of BCS at service with BCS at calving, calving interval, gestation length, number of services per conception were low but positive: 0.16, 0.26. 0.08 and 0.06. respectively. Phenotypic correlations of BCS at calving with calving interval, gestation length and number of services per conception were estimated to be also low and positive: 0.10, 0.13 and 0.10. respectively. However, phenotypic correlations between calving interval and gestation length, and between gestation length and number of services per conception were negative but low as - 0.11 and- 0.13 each.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2006.10a
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• pp.102-103
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• 2006

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.241-245
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• 2006

This study was carried out to investigate the effect of intra-uterine infusion of lipopolysaccharide (LPS) on reproductive performance in lactating dairy cows. Conception rate at first service was higher (56.0%) in dairy cows treated with LPS compared to non-treated cows (20.0 %). Cumulative conception rate by overall services (more than 2 services) after LPS treatment was also higher (64.0%) in dairy cows treated with LPS compared to non-treated cows (40.0%). Services per conception was significantly higher in control ($2.0{\pm}0.1$) compared with LPS ($1.2{\pm}0.4$) treated group (p<0.05).

• Journal of Embryo Transfer
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• v.22 no.3
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• pp.195-198
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• 2007

This study was carried out to investigate the effects of hormones treated (progesterone, and combination of progesterone and estradiol) on the reproductive performance of dairy cattle. The intravaginal CIDR was inserted in the vagina of cow on day 14 (P-7, PE-7), 16 (P-5, PE-5) and 18 (P-3, PE-3) post-insemination to stimulate progesterone secretion with (PE) and without estradiol(P). The CIDR was removed on 7 (P-7, PE-7), 5 (P-5, PE-5) and 3 (P-3, PE-3) days after. The cows for control group were not treated with CIDR or hormones. Conception rate, the duration needed for conception after AI and the number of AI services needed for conception were measured. Conception rate in control, CIDR without estradiol (P-7, P-5 and P-3) and CIDR treated (PE-7, PE-5 and PE-3) cows were 15.8%, 40.0%, 31.5%, 28.6%, 62.5%, 50.0% and 0%, respectively. The days needed for conception after AI in control, P-7, P-5, p-3, PE-7, PE-5 and PE-3 were 64.9, 63.0, 59.1, 8.0, 0.0, 18.9 and 83.3 days, respectively. The days needed for conception in cows treated with CIDR (PE-7) has shown longer than control and PE-3 (p<0.05). The number of AI services needed for conception in control, CIDR (PE-7, PE-5 and PE-3) and CIDR without estradiol treated cows (P-7, P-5 and P-3) were 27, 2.3, 1.9, 1.3, 1.0, 1.7 and 2.8 times, respectively. The number of AI services needed for conception have shown significantly lower in PE-7 compared to control and PE-3.

• Reproductive and Developmental Biology
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• v.30 no.3
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• pp.195-199
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• 2006

This study was carried out to investigate the effect intra-uterine infusion of lipopolysaccharides(LPS) on the reproductive performance of dairy cows with retained placenta, The LPS isolated from Bacteroids helcogenes and Fusobacterium varium was injected at the rate of 100 ${\mu}g$ with 30 ml of phospahte buffer saline in each cow(n=33) at day 20 postpartum. Twelve cows with retained placenta were not heated with LPS and served as a control. Conception rate after first service was 0% and 33,3% for control and LPS groups, respectively. Service period was $149.6{\pm}34.3\;and\;53.0{\pm}12.5$ days for control and LPS groups, respectively(p<0.05). Services per conception was $3.6{\pm}0.8\;and\;2.1{\pm}0.3$ for control and LPS groups, respectively(p<0.05). In conclusion, intra-uterine infusion of LPS in cows with retained placenta can reduce the service period and services per conception. Reduced service period can improve the dairy farm profitability by decreasing cost un feeding and management of cows.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.233-238
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• 2005

This study was carried out to investigate effects of claw trimming on reproductive efficiency in lactating cow. The results obtained were summarized as follows: 1. Days to 1st postpartum service were 180.9$\pm$47.2 days for control and 111.9$\pm$17.1 days for claw trimming. 2. Conception rate by 1st postpartum service was $25.0\%$ for control and $66.7\%$ for claw trimming. 3. Days to 1st postpartum conception were 258.1$\pm$43.3 days for control and 151.6$\pm$26.2 days for claw trimming(p<0.05). 4. Services per conception were 1.88$\pm$0.23 times for control and 1.44$\pm$0.18 times for claw trimming. 5. Calving interval was 489.3$\pm$47.2 days for control and 430.8$\pm$26.2 days for claw trimming.