• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.141-145
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• 1977

This study was conducted from 1974 to 1977 at Chedong Animal Farm in Che-Ju to determine the effect of sex of calves, birth year and season, breeds and crossing methods on the birth weight of cattle. A total of 1020 calves from Angus, Charolais, Hereford breeds and their crossbred were used for the study and least square methods was applied to analysis the data. Birth weight of male calves was 1kg heavier than that of female. Highly significant differences were obtained in the effects of birthyear on the birth weight, i.e. the cattle born in 1976 and 1977 was 0.9 and 0.2kg heavier in birth weight than those born in 1975. The cattle born in 1974, when the farm was established, was 1.7kg lighter than those in 1975. The calves born in the spring and the summer was 0.6 and 0.3kg heavier in birth weight than those born in the winter. The calves born in the fall was 0.9kg lighter than the calves born in the winter. In birth weight, Charolais breed were 0.4kg heavier than those from Hereford breed. Angus breed were 1.1kg lighter than Hereford. The crossbred between Charolais and Hereford breed were 1.5kg heavier than the Hereford. The birth weight of calves from Angus and Hereford crossbred and Angus and Charolais crossbred were 0.6 and 0.4kg lighter, than Hereford breed respectively.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.113-121
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• 2012

A total of 150,624 records of Holstein milk production collected from 2005 to 2009 were analyzed to investigate the effects of two different contemporary group definitions, parity and somatic cell score (SCS). The first definition (H BY S) of contemporary group was milking cows and heifers born in the same year and season. And the second thing (H CY S) was milking cow and heifers that delivered calves in the same year and season. Effects of contemporary group, parity and regression effect on SCS from two models were highly significant sources of variation. Coverage of variation ($R^2$) was somewhat higher in models with H BY S as contemporary group. From multivariate models with H BY S, phenotypic correlation coefficients of milk components were estimated high and positive. However, the phenotypic correlation coefficient between milk yield and SCS was -0.09, which was low enough to evidence no correlation between them. Phenotypic correlation between SCS and butter fat or between SCS and protein were also negligible but negative. From multivariate models with H CY S as contemporary group, phenotypic correlation among milk traits and SCS were similar to the estimates from models with H BY S. However, SCS in these models were lowly but negatively correlated with milk yield, milk protein, butter fat or SNF, and the phenotypic correlation coefficients of which were -0.10, -0.08, -0.08, -0.11, respectively.

• Journal of Animal Science and Technology
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• v.54 no.4
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• pp.247-253
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• 2012

Ultrasound measures of back fat thickness (UBF), eye muscle area (UEMA) and marbling score (UMS) and carcass measures of carcass weight (CW), backfat thickness (BF), eye muscle area (EMA) and marbling score (MS) were available on 26,129 Hanwoo steers. Statistically significant differences by regions of the farms location and birth years-seasons for the steers taken ultrasound measures and their carcass measures (p<0.01) were found. Steers in Gyeonggi province showed the highest values in ultrasound measures and carcass traits except in BF compared to steers in the other provinces. Comparing between ultrasound and carcass measures, UBF was thicker in general than BF in all regions except in Daejeon city. UEMA was higher than EMA in all regions except in Gyeonggior in Jeju provinces. Especially, the difference in Jeonnam province between UEMA and EMA was $7cm^2$ while the differences between UMS and MS ranged from 0.9 to 2.26 depending on the regions of steers located. Steers born in spring showed greater ultrasound or carcass values than those born in autumn. However, carcass measures of steers born in autumn were greater than those born in spring, 2009 except MS. The pearson and residual correlations were 0.63 and 0.65 between UBF and BF, 0.31 and 0.32 between UEMA and EMA and 0.56 and 0.56 between UMS and MS, respectively.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.183-189
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• 1999

A study was conducted to estimate the effects of parity of dam, sex, year and season of birth on gestation length and birth weight in Korean native and Yanbian yellow cows. A total of 1,206 reproduction records (587 Korean native cows, 619 Yanbian yellow cows) were collected from Daekwamyeong Branch Institute, National Livestock Research Institute in Korea and Yanbian region in China from 1995 to 1998. The least square means for gestation length and birth weight of Korean native cows and Yanbian yellow cows were 287.3$\pm$0.60 and 282.3$\pm$0.80 days, 24.9$\pm$0.25 and 25.2$\pm$0.24kg, respectively. Gestation length and birth weight were increased significantly as parity of dam progressed in Korean native cow(p＜0.01), but were not significant in Yanbian yellow cow. Birth weight of male calf was heavier than that of female calf in Korean native cow and Yanbian yellow cow(p＜0.01). Gestation length of Korean native cow born male calf was longer than that of Korean native cow born female calf(p＜0.01), but was not significant in Yanbian yellow cow. Effect of birth year on birth weight was significant in Korean native cow and Yanbian yellow cow(p＜0.01), but effect of birth year on gestation length was not significant. Birth weight of spring-born calf was the heaviest and that of fall-born calf was the smallest in Korean native cow and Yanbian yellow cow(p＜0.01).

• Journal of Animal Science and Technology
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• v.51 no.3
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• pp.255-262
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• 2009

Current study was conducted to investigate the influence of parity and region variation in ultrasound live carcass traits of Hanwoo cows. A total of 1,386 heads of Hanwoo cows, spreading over six regions in Gangwon province of South Korea, were measured for longissimus muscle area, back fat thickness, marbling score and rump fat thickness by using real-time ultrasound method. The results revealed that, positive correlations were found in all ultrasound live carcass traits. All live carcass traits were increased in accordance with parity until the sixth, and then decreased thereafter. Statistical significant differences (p<0.01) were found among regions in ultrasound live carcass traits, e.g. Hanwoo cows showed highest longissimus muscle area and marbling score in Hwacheon, while the lowest back fat thickness and rump fat thickness were observed in Yanggu. Greater longissimus muscle area and marbling scores were found in Hanwoo cows which were born during autumn, 2000. Moreover, individuals born during autumn, 2005 and 2006 showed a thicker back fat and rump fat thickness. Back fat thickness had the highest positive correlation with rump fat thickness, while rib eye area and rump fat thickness had the lowest correlation.