• Journal of Veterinary Clinics
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• v.30 no.6
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• pp.435-441
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• 2013

This retrospective study evaluated the effects of the interval from calving to first insemination (ICFI) and days open (DO) on the reproductive performance in dairy cows. In the first analysis, data from 705 cows were grouped based on the ICFI: short (30-60 days, n=217), medium (61-90 days, n=309), and long (91-150 days, n=179). The occurrence of endometritis was greater in the long group than in short and medium groups (p<0.05). The occurrence of ovarian cysts increased with increasing ICFI (p<0.05), while body condition score (BCS) during the 5 month postpartum period was lower with increasing ICFI (p<0.01). The hazard of pregnancy by 365 days in milk (DIM) was lower (hazard ratio [HR]=0.70, p<0.0001) in the long group, but higher (HR=1.41, p<0.0001) in the short group compared with the medium group. In the second analysis, data from 436 cows were grouped based on the DO: short (30-90 days, n=154), medium (91-180 days, n=183), and long (181-360 days, n=99). The occurrence of a retained placenta was greater in the long group than in the medium group (p < 0.05). Ovarian cysts occurred more frequently in medium and long groups than in the short group (p=0.08). BCS was lower in the short group compared with medium and long groups at month 1 postpartum (p<0.05). Milk yield (kg/day) was greater in the medium group compared with the short group at months 2 to 5 postpartum (p<0.05). The hazard of first insemination by 150 DIM was lower in the long group than in the short group (HR=0.73; p<0.02). The hazard of pregnancy by 365 DIM was lower (HR=0.64, p<0.0001) in the long group than in the medium group, while the hazard did not differ between short and medium groups (p>0.05). Moreover, the culling rate was greater in the long group than in the short group (p<0.05). In conclusion, a longer ICFI and DO resulted in reduced reproductive performance in dairy cows, which was attributable to an increase in postpartum diseases, a lower BCS and a greater milk yield.

• 종축개량
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• v.9 no.4
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• pp.18-21
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• 1987

• Korean Journal of Agricultural Science
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• v.11 no.2
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• pp.218-222
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• 1984

The present study was carried out to investigate the behaviour of parturition, nursing and sleep with a total of 40 sows and 420 piglets during 28 days from July 6 to August 3, 1984. The results obtained in this study were as follows: 1. About half number of sows employed were recumbent and lay on their right or left side throughout the process of delivery, but the rest changed their lying sides during the delivery, about 65% of piglets born were presented anteriorly. During nursing 51.3% of sows were recumbent and lay on their left side. 2. The entire farrowing process normally lasted 4 hr. Piglets were expelled at an average rate of one for every 19.3mim. 3. The first suckling attempt was observed at about 24.3min after birth. "Teat order" were established within 32hr after birth. 4. The duration and time of nursing were 35.8 second and 24.6 times/day, respectively, in the first day of piglet life. However, they tended to shorten with the advance of lactation. The intervals between nursings were 58.5 min. in the first day of piglet life, but it tended to lengthen with the advance of lactation. 5. The sows were awake for 31.7%. drowsy for 16.7%, and asleep for 51.6% of the 24hr period a day.

• Journal of Veterinary Clinics
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• v.25 no.4
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• pp.280-285
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• 2008

This study evaluated the correlation between the body condition score (BCS) during prepartum, calving and postpartum periods and the reproductive performance of Korean brown cattle. The BCSs of 33 cows who underwent 73 calvings over a two and a half period [the parities of the cows ranged from 1 to 4 ($mean{\pm}SD,\;2.0{\pm}0.9$)] were scored at months 2 and 1 prepartum, calving, and every month postpartum until month 7. A marked prepartum loss of BCS in the month preceding calving was noted. The correlations between the interval from calving to conception and the month 1 prepartum, calving and months 1 and 2 postpartum BCSs were analyzed by Pearson correlation analysis. The correlation between the interval from calving to conception and the prepartum body condition loss was also evaluated. The interval from calving to conception correlated positively with the month 1 prepartum BCS (r = 0.389, P = 0.0007) and the prepartum body condition loss (r = 0.488, P < 0.0001) but did not correlate significantly with the BCS at calving (r=-0.070, P=0.56) or months 1 (r=0.107, P=0.37) or 2 (r=0.102, P=0.39) postpartum. The prepartum body condition loss correlated positively with the month 1 prepartum BCS (r=0.587, P<0.0001). In conclusion, the month 1 prepartum BCS may be a good criterion for predicting subsequent reproductive performance. Moreover, the prevention of obesity and/or excessive prepartum body condition loss may result in higher fertility in Korean brown cattle.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2003.10a
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• pp.120-120
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• 2003

• Journal of agriculture & life science
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• v.50 no.5
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• pp.173-182
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• 2016

This study was aimed to identify the phenotypic relationships between calving interval and lactation curve parameters in Korean Holstein cow. The data of 36,505 lactation records was obtained from the Dairy Herd Improvement program run by Dairy Cattle Improvemnet Center of National Agricultural Federation of Korea. All lactation records were collectied from the multiparous cows calving between 2011 to 2013. The estimated lactation curves were drawn using Wood model based on actual milk yield records, and NLIN Procedure of SAS program (ver. 9.2). General linear multivariate models for calving interval, 305-d milk yield, lactation parameters(A, b, c), persistency, peak day, and peak yield included fixed effects of calving year-season (spring, summer, fall and winter) and parity(2, 3 and 4). For calving interval, 305-d milk yield, lactation parameters(A, b, c), persistency, peak day and peak yield, all two fixed effect(calving year-season, parity) were significant(p<0.05). The estimated lactation functions using Wood model for 2, 3, and 4 parity were yt=24.66t0.175e-0.00302t, yt=24.69t0.192e-0.00334t, and yt=24.22t0.200e-0.00341t, respectively. Phenotypic correlation (partial residual correlation) between calving interval and 305-d milk yield, A, b, c, persistency, peak day, and peak yield were 0.093, -0.014, 0.028, -0.046, 0.099, 0.085, and 0.052, respectively. To conclude, if calving interval increase then ascent to peak, persistency, peak day and peak yield are increase, and descent after peak is decrease. So, total 305-d milk yield is increase.

• Journal of Embryo Transfer
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• v.31 no.3
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• pp.273-279
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• 2016

The Korean native cattle, Hanwoo, is the most popular breed of beef cattle in Korea. However, the reproductive performance data are limited although reproduction is one of the most economically and biologically important in beef production. Therefore, this study was undertaken to investigate reproductive performance parameters including calving interval, parity for life time production. Data collected from 206,827 calvings were analyzed. There were no significant differences in calving interval and gestation days as parity increased from 2nd and 13rd parity cow, from spring to winter. However, we found a dramatic increase in calving interval after year 2000. About 1 month were increased per year ( y = 30.578x + 344.45 $R^2=0.9157$). Interestingly, we observed that parities for life time can be affected by birth weight. Calves with 23 kg at birth showed highest parities, $3.4{\pm}2.0$ times. In summary, this study provides valuable data on reproductive performance of Hanwoo and the data presented here can be used as a standard target for optimising and enhancing reproductive performance.

• 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 Developmental Biology Conference
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• 2003.10a
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• pp.120-120
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• 2003

고능력 젖소와 보통능력 젖소의 번식능력을 비교하기 위하여 progesterone을 분석하여 분만후 초발정일을 추정하였고, 번식자료를 통하여 분만 후 번식성적을 조사하였으며, 또한 비유능력 및 Body condition score(BCS) 에 따른 $PGF_2a + PGF_2a+CIDR$ program 투입 효과를 구명하기 위하여 분만 후 40일째에 $PGF_2a$를 1차 처리한 후 발정이 발현되지 않은 개체에 대하여 1 차 처리후 14일째에 다시 2차 $PGF_2a$를 처리하였고 2차 $PGF_2a$ 처리후에도 발정이 발현되지 않은 개체에 대하여 2차 $PGF_2a$ 처리후 5일째에 CIDR plus를 처리하여 발정유기율을 조사분석하였던 바, 그 결과를 요약하면 다음과 같다. 가. 보통능력우와 고능력우의 분만후 progesterone peak를 나타내는 일수는 각각 $38.8 \pm 11.1$ 및 $39.6 \pm 9.7$일로 거의 비슷한 경향을 나타내었음 나. 보통능력우와 고능력우의 분만후 발정재귀일수는 각각 $99.4 \pm 71.6$ 및 $117 7 \pm 78.6$일로 고능력우에서 18.3일 늦어지는 경향이었음 다 보통능력우와 고능력우의 분만후 수태일수에 있어서 각각 $145.9 \pm 102.8$및 $165.9 \pm 100.8$일로 고능력우에서 20일 늦어지는 경향이었음 라. 보통능력우와 고능력우의 분만간격에 있어서 각각 421.5 \pm 107.2$ 및 $448.4 \pm 108.7$일로 고능력우에서 26.9일 늦어지는 경향을 나타내었음 마 보통능력우와 고능력우에 있어서 1차 $PGF_2a$ 처리시 각각 39.1% 및 60.0%, 2차 $PGF_2a$ 처리시 각각 42.9% 및 70.0%, CIDR plus 처리시 50.0% 및 66.7%의 발정 유기율을 나타내었음 바. BCS에 따라 $PGF_2a + PGF_2a+CIDR$ plus program을 투입한 결과 BCS 2.5 이하와 BCS 2.75-3.50에 있어서 1차 $PGF_2a$ 처리시 각각 47.4% 및 48.3%, 2차 $PGF_2a$ 처리시 각각 40.0% 및 66.7%, CIDR plus 처리시 각 각 50.0% 및 80.0%의 발정 유기율을 나타내었음

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.285-285
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• 2004

농가의 사육규모 확대에 적합한 한우의 종합적 번식관리 기술을 농가의 기술 수준에 따라 효율적으로 활용이 가능하도록 개발하고자 하며 사육규모 100두 내외의 전업 번식농가에서 암소의 번식관리에 중요한 영향을 미치는 초수정 월령, 수태율, 수태당 수정회수 및 분만간격 등을 구명하고자 수행하였다. (중략)