• Journal of Animal Science and Technology
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• v.46 no.6
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• pp.989-998
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• 2004

The objectives of this work was to investigate the effects of feeding type of concentrates during growing period and slaughter age on growth performance, feed efficiency and carcass characteristics in growing-fattening Holstein steers. Treatments were two concentrates feeding types(ad libitum or restricted 1.9% of BW) and three slaughter ages(at 19, 22 or 25 mo). Body weight at slaughter was numerically higher(approx. 8.3%) for the restricted than the ad libitum feeding groups. TDN intake rate was higher(8.4%) for the restricted than the ad libitum feeding groups. One mo slaughter delay increased TDN intake by 4%. Despite the lack of significances, higher back fat thickness and rib-eye area appeared in the restricted feeding or the late slaughter groups compared with the ad libitum feeding or the early slaughter groups. Marbling score(mean 2.46) numerically increased when the steers were restrictively fed concentrates compared with the ad libitum feeding groups. In addition, significant increases in the marbling score were associated with the slaughter age delay. In economic analysis, increases in total income were associated with the restricted feeding and the slaughter age delay. Whereas the highest monthly income appeared in the restricted feeding-and-slaughter at 22 mo group. In conclusion, the optimal feeding system may be 1) the restricted concentrates feeding(1.9% of BW) during growing period and 2) the late slaughter age(22${\sim}$25 mo of age) in growing-fattening Holstein steers fed rice straw.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.711-724
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• 2003

Some growth curve models were used to fit individual growth of 1,083 Hanwoo cows born from 1970 to 2001 in Daekwanryeong branch, National Livestock Research Institute(NLRI). The effects of year-season of birth and age of dam were analyzed. In analysis of variance for growth curve parameters, the effects of birth year-season were significant for mature weight(A), growth ratio(b) and maturing rate(k)(P〈.01). The effects of age of dam were significant for growth ratio(b) but not significant for mature weight(A) and maturing rate(k). The linear term of the covariate of age at the final weights was significant for the A(P〈.01) and k(P〈.01) of Gompertz model, von Bertalanffy model and Logistic model. For the growth curve parameters fitted on individual data using Gompertz model, von Bertalanffy model and Logistic model, resulting the linear contrasts(fall-spring), Least square means of A in three nonlinear models were higher cows born at fall and A of Logistic model was significant(P〈.05) between the seasons. According to the results of the least square means of growth curve parameters by age of dam, least square means of mature weight(A) in Gompertz model was largest in 6 year and smallest estimating for 3 and 8 years of age of dam. The growth ratio(b) was largest in 2 year of age of dam and smallest estimating in 8 year. The A and k were not different by age of dam(p〉.05), On the other hand, the b was different by age of dam(p〈.01). The estimate of A in von Bertalanffy model was largest in 6 year and smallest in 8 and 9 years of age of dam. The b was largest in 2 year and tend to decline as age of dam increased. The A and k were not different by age of dam(p〉.05), On the other hand, the b was highly significant by age of dam(p〈.01).

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.667-678
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• 2003

The objectives of this study were to investigate the genetic characteristics of body weight by growth periods for Hanwoo. A total of 1,736 records were used for body weight. The data for body weights were collected from 1990 to 2000 in Daekwanryong branch, National Livestock Research Institute(NLRI). Estimates of (co)variance components were obtained by derivative-free Restricted Maximum Likelihood (DF-REML). The results are summarized as follows; The means for the weights were 25.60, 79.31, 98.91, 145.40, 283.26, 392.32, 545.65kg at birth, 3, 4, 6, 12, 18, 24month postpartum, respectively. The effects of calving year-season were significant for the milk yield of cow. Heritability estimates of direct genetic effects for birth weight were 0.54(all), 0.52(female), 0.36(male) in modelⅠ, 0.45(all), 0.41(female), 0.24(male) in modelⅡ, and heritabilities estimates of direct genetic effects for 4 month(weaning) weight were 0.47(all), 0.33(female), 0.28(male) in modelⅠ, 0.38(all), 0.21(female), 0.21(male) in modelⅡ. Heritability estimates for male and female data differed from those for combined data. The estimates became smaller for the body weights at 12 month or later(0.13～0.05). The heritabilities of average daily gain were smaller than those for body weights, but showed that the similar pattern to body weights.

• Journal of Animal Science and Technology
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• v.48 no.5
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• pp.727-738
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• 2006

This study was carried out to investigate the effect of feeding levels and periods of Rhus verniciflua Stokes (RVS) on the quality of M. longissimus from gilts (Landrace×Yorkshire×Duroc) at finishing stage. The gilts were fed diets containing 0 (control), 2 and 4% RVS for 5 weeks (the latter feeding periods) and 8 weeks (the first feeding periods+the latter feeding periods) before slaughtering, respectively. Samples were stored at 3±0.2℃ for 8 days. Crude fat content was decreased by feeding diets of 4% RVS (p<0.05). Water-holding capacity (WHC) was higher in RVS treatments than in control during storage (p<0.05). L*(Lightness) value was higher in 5 weeks-RVS treatment than in control during storage (p<0.05). a*(Redness) and b*(yellowness) were not affected by the levels and periods of RVS supplementation. Thiobarbituric acid reactive substances (TBARS) value was lower in RVS treatment than in control (p<0.05), and the 5 weeks with 4% RVS treatment showed the highest antioxidative activity. Fatty acid compositions of pork were changed by RVS feeding levels and periods. The meat supplemented with RVS showed high levels of unsaturated fatty acid (UFA) composition and monounsaturated fatty acid (MUFA)/saturated fatty acid (SFA) ratio compared with control. The dietary 8 weeks-RVS treatments had lower stearic acid(18:0) and higher polyunsaturated fatty acid (PUFA) contents than in other treatments. Melting point of backfat also decreased by increasing the level and period of RVS supplementation (p<0.05). Therefore, RVS fed pork decreased fat content and melting point, increased WHC and UFA composition, and delayed lipid oxidation during storage.

• Journal of Animal Science and Technology
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• v.51 no.4
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• pp.265-272
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• 2009

A total of 486 milk records were collected from 16 diary farms in Imsil-gun, Jeollabuk-do. Results obtained were as follows: The average 3MG (amount of milk within the first three minute) was 7.44 kg and 55% of total milk yield was produced within 3 min. The average of SPL (% of foam in milk) was 33.93% and the average of MNG (strip yield) was 0.14 kg, which was less than 1% of total milk yield. The averages of HMF (highest milk flow), HMG (maximum milk flow rate in one minute) and DMHG (average milk flow in the main milking phase) were 3.03 kg/min, 2.94 kg/min and 2.05 kg/min, respectively and the average milking speed in Imsil-gun was slower than other regions. The average of tS500(time to reach 0.5 kg/min at beginning) was 0.23min (about 14 seconds) and that of tMGG (duration of the total milking) was 7.75min. The average tMBG (duration of the dry milking phase) was 0.58 min (35 seconds) and that of tMNG (duration of the stripping phase) was 0.42min (14 seconds). The averages of ELHMF (electrical conductivity at highest milk flow) and ELAP (beginning peak level of the electrical conductivity) were 6.81 mS/cm and 7.58 mS/cm, respectively. The average of ELMAX (maximum electrical conductivity) was 7.48 mS/cm and that of ELAD (beginning peak difference of the electrical conductivity) was 0.61 mS/cm. While the total milk yields for DMHG, tMHG (duration of the main milking phase), tPL (duration of the plateau phase), tAB (duration of the descending phase) and tMGG were positively correlated (0.35~0.54), those for tMBG and SPL were negatively correlated (-0.11 and -0.27). As the DMHG increased, tMHG, tPL, tAB, tMGG and SPL decreased. While the cows with higher electrical conductivity at the beginning of milking had less somatic cell counts, cows with higher electrical conductivity after the peak of milk yield had more somatic cell counts. The results of this experiment indicated that through milking based on milking and lactating standards and the regular checking of milking status, the qualities of milk and milk yields could be improved.

• Journal of Animal Science and Technology
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• v.50 no.2
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• pp.185-198
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• 2008

Influences of dietary brown seaweed(BSW) on the nutrient metabolism, anti-oxidant enzyme activity and cell-mediated immune response were studied in broiler chicks activated acute phase response. 72 Hatched male broiler chicks(Ross) were divided into 12 pens, 6 heads per pen, and fed the BSW 0.0% (Basal) or 2.0% diet, respectively, and injected with the Salmonella typhimurium lipopoly saccharide(LPS) for activation of the acute phase response three times at 8, 10 and 12 d of age. During 4 wks of experimental feeding, growth performance of broiler chicks was not affected by dietary BSW and the acute phase response. Compared with control birds, the acute phase response did not affect the daily weight gain in birds fed BSW 2.0% diet, decreased nitrogen balance(NB) or metabolizable energy(ME) utilization per metabolic body size(kg0.75), and enhanced activities of peroxidase or extracellular SOD(EcSOD), tumor necrosis factor-alpha and ovotransferrin in plasma and MnSOD and CuZnSOD in erythrocyte cytosol. Compared to BSW 0.0% diet, 2.0% diet enhanced protein retention(NB) per kg0.75 regardless the acute phase response, did not affect uric acid nitrogen excretion(UAN) per kg0.75 in birds during the acute phase response, decreased(p<0.05) the UAN excretion per kg0.75 in control birds. And BSW 2.0% diet also decreased(p<0.05) plasma peroxide level and erythrocyte peroxidase or MnSOD activity but increased plasma peroxidase and EcSOD activity and interleukin-1 activity secreted from LPS-stimulated PBMC in 4 week broiler chicks.

• Journal of Environmental Impact Assessment
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• v.25 no.3
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• pp.209-221
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• 2016

The section from water source to 2.6km upper stream of Hantan River is protected as the drinking water quality protection area according to guidelines of Ministry of Environment, because water source of the Gwanin water intake plant has been known the river. However, opinions were consistently brought up that the standard of water source protection zone must be changed with using underground water as water source because of contribution possibility of underground water as the water source of Gwanin water intake facility. In this regard, hydrogeologic investigation including resistivity survey and hydrogeochemical investigation were carried out to assess water source and infiltration of contaminant for the plant. Quaternary basaltic rocks (50m thick with four layers) covered most of the study area on the granite basement. As the result of the resistivity survey, it is revealed that permeable aquifer is distributed in the boundary of two layers: the basaltic layer with low resistivity; and the granite with high resistivity. Considering of outflow from Gwanin water intake facility, the area possessing underground water was estimated at least $5.7km^2$. The underground water recharged from Cheorwon plain was presumed to outflow along the surface of unconformity plane of basalt and granite. Based on field parameters and major dissolved constituents, groundwater and river water clearly distinguished and the spring water was similar to groundwater from the basaltic aquifer. Temporal variation of $SiO_2$, Mg, $NO_3$, and $SO_4$ concentrations indicated that spring water and nearby groundwater were originated from the basaltic aquifer and other groundwater from granitic aquifer. In conclusion, the spring of the Gwanin water intake plant was distinguished from river water in terms of hydrogeochemical characteristics and mainly contributed from the basaltic aquifer.

• Journal of Science Education
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• v.42 no.2
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• pp.256-271
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• 2018

The study aimed to investigate how the science gifted connect and integrate science concepts in the process of problem finding. Research subject was sampled from 228 applicants for a science gifted education center affiliated with a university in 2015. A creative problem solving test (CPST) in science, which administered as an admission process, was utilized as a reference to sample two groups. Sixty-seven students from top 30% in test scores were selected for the upper group and 64 students from bottom 30% in test scores were selected for the lower group. The CPST, which was developed by researchers, included one item about how to connect two science concepts among eight science concepts, sound, electricity, weight, temperature, respiration, photosynthesis, weather, and earthquake extracted from elementary science curriculum. As results, there were differences in choosing two concepts among four science major areas. The ways of connecting science concepts were characterized by three categories, relation-based, similarity-based, and dissimilarity-based. In addition, relation-based was characterized by attributes, means, influences, predictions, and causes; similarity-based was by attributes, objects, scientific principles, and phenomena, and dissimilarity-based was by parallel, resource, and deletion. There were significant (p<.000) differences in ways of connecting science concepts between the upper and the lower groups. The upper group students preferred connecting science concepts of inter-science subjects while the lower group students preferred connecting science concepts of intra-science subject. The upper group students showed a tendency to connect the science concepts based on similarity. In contrast, the lower group students frequently showed ways of connecting the science concepts based on dissimilarity. In particular, they simply parallelled science concepts.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.6
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• pp.139-151
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• 2007

To protect the surface of ground-cutting slopes and ground-raised slopes and to recover environment-friendly slopes at the national road expansion construction between Gamchon and Yaechon, test-construction work was done using several modes of hydro-seeding measures to select a suitable construction method through the field survey; the results were as follows : As a result of survey on physio-chemical characteristics of soil, the average soil inclination on ground-raised slopes was from 4.73 mm to 5.37 mm; the average soil acidity was from pH 6.47 to 6.73; the average soil humidity was within the scope of 0.57~1.70 %,; the average soil inclination on ground-cutting slopes was 9.17~10.43mm; the average soil acidity was pH 6.67~6.77 and the average soil humidity was within the scope of 0.53~1.27 %; considered overall, they showed generally satisfactory base materials for plant breeding. As a result of the number of sprouting individuals, the average sprouting number of individuals on test spots executed by Coir net with Seed spray construction methods and the average number of sprouting individuals on other test spots executed by furrow-digging with Seed spray and Straw mat-mulching measures were 1,172 number of per square meter and 970 number of per square meter respectively; thus they showed higher numerical value comparing with other test spots. Likewise, the average number of sprouting individuals on test spots of the ground-cutting slopes executed by Coir net with Seed spray method and the average number of sprouting individuals on other test spot executed by furrow-digger with Seed spray and Straw mat-mulching measures were found to be 1,107 number of per square meter and 1,105 number of per square meter respectively, whose numerical value showed rather higher other test spots. As a result of a survey on living plants' breeding index [dried weight], the weight in dried state on test spots executed by Coir net with Seed spray method and other test spots executed by furrow-digger with Seed spray and Straw mat-mulching measures on both ground-raised and ground-cutting slopes was found to be higher and showed similar characteristics statistically. As a result of survey on the surface-covering degree of ground-raised slopes, nine weeks after test construction, test spots executed by Coir net with Seed spray method and other test spots executed by furrow-digger with Seed spray and Straw mat-mulching measures showed commonly more than 70% of surface-covering degree, but other test spots showed only below 35% of surface covering degree; especially in case of test spots by Verdvol seed spray measures, they showed 10% of the lowest surface-covering. Surface-covering degree on the test spot of ground-cutting slopes nine weeks after test construction showed more than 75% both executed by Coir net with Seed spray construction method and executed by furrow-digger with Seed spray and Straw mat-mulching measures. As a result of survey on appearing plants on the test spots, there dominates Eragrostis curvula both on ground-raised slopes and on ground-cutting slopes with other seeding plant life's lower breeding and there appear intruders, such as Setaria viridis Beauv, Digitaria sanguinalis Scop, and Chenopodium album var.centrorubrum Makino. As for water-borne excavation and soil's washing-away on the slopes, there happened less washing-away and water-borne excavation with good breeding of plant life on test spots executed both by Coir net with Seed spray construction method and by furrow-digger with Seed spray and Straw mat-mulching measures, but there happened much more soil's washing-away along with water-home excavation at the test spot executed by Seed spray with measures. After the research results of test construction sites are examined overall, it's presumed that furrow-digger with Seed spray and Straw mat-mulching measures [interval between lines is 40cm, 5cm in depth] will be preferred to prevent erosion and water-home excavation of slopes located within the construction sites.

• Journal of Embryo Transfer
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• v.21 no.2
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• pp.137-146
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• 2006

The objective of this study was to examine the effect of donor cell types, the source of recipient oocytes and estrous synchronization on pregnancy and delivery rates of somatic cell nuclear transfer (SCNT) embryos in Korean native goats. Recipient oocytes were surgically collected after superovulation. Ear cells and fetal fibroblasts were collected and cultured in serum-starvation condition (TCM-199 + 0.5% FBS) for cell confluence. The zonae pellucidae of in vivo- and in vitro-matured oocytes were partially drilled using a laser system. Single somatic cell was transferred into the enucleated oocyte. The reconstructed oocytes were electrically fused with 0.3 M mannitol. After the fusion, embryos were activated by Ionomycin+6-DMAP. NT embryos were cultured in mSOF medium supplemented with 0.8% BSA at $39^{\circ}C$ in an atmosphere of 5% $CO_2$, 5% $O_2$, 90% $N_2$ for 12 to 20 hr. One hundred and two SCNT embryos were transferred into 20 recipients and pregnancy rate at days 30 was 20.0%. Of them, one developed to term and delivered 1 kid. Ear cells showed significantly higher fusion (63.8 vs. 26.5%) and pregnancy rates (20.0 vs. 0.0%) than those of fetal fibroblast (p<0.05). The recipients synchronized by CIDR showed significantly lower pregnancy rates compared to that of recipient in natural estrus ($0.0{\sim}25.0%$ vs. 100%) (p<0.05). Cloned kid was born from the recipient in natural estrus. For the synchronization of estrus between recipient and donor, there was no difference between treatments (${\pm}0$ vs. +12 hr) in pregnancy rate. The first healthy cloned kid (Jinsoonny) was produced by transfer of SCNT embryos derived from in vivo oocytes and ear cells into a recipient goat whose estrus was synchronized with the donor. These results imply that donor cells for nuclear transfer may affect the success rate, and the estrus synchronization between donor and recipient animals can also be important.