• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.337-347
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• 2006

Papers made from unbleached and bleached bagasse chemimechanical pulp were chemically modified by acetylation. The effects of irradiation on unbleached and bleached also reduced papers of bagasse chemimechanical pulp before and after acetylation were investigated in this study. Chemimechanical pulp was prepared from bagasse and then bleached with hydrogen peroxide. Unbleached and hydrogen bleached pulps were reduced by Sodium borohydride in different procedures. Paper sheets were prepared from pulps and then acetylated using a technical grade of acetic anhydride. Accelerated photo-aging was run on the samples using fluorescent lamps to verify photo-stability of paper sheets before and after pretreatments. Brightness reversion (as Post-color number) and other optical properties of the paper sheets were measured. Efficient inhibition of photo-yellowing of papers made from bagasse CMP was achieved by acetylation. The acetylated unbleached CMP was noticeably photo-bleached during irradiation. Sodium borohydride reduction followed by acetylation had the same effect as acetylation alone at the same degree of reaction time and reductive treatment did not affect the yellowing rate to any great extent. The pre-reduced, acetylated unbleached papers were, however, not brightened during irradiation. Calculation done by Kubelka-Munk equation showed that reductive treatment had little effect in reducing the photo-yellowing of paper made from CMP pulp; a small stabilization effect was observed in the case of bleached CMP, while unbleached CMP was slightly more prone to discolor in the later phase of photo-reversion. The improved stability towards light may was closely related to the decrease in the phenolic hydroxyl content as a result of blocking by acetyl groups during treatment with acetic anhydride. The results support the hypothesis that phenolic hydroxyl has an important role in the process of photo-reversion of high-yield pulps. The results obtained in this study demonstrate that the acetylation of paper manufactured from peroxide bleached Bagasse CMP significantly retards light-induced discoloration. The inhibition of yellowing is connected with a decrease in the phenolic hydroxyl content of both unbleached and peroxide bleached papers.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.671-682
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• 2019

This study was conducted to evaluate the effects of rumen-protected methionine and lysine (RPML) on the growth performance, carcass characteristics, and meat properties of Hanwoo steers. Fourteen late fattening steers were randomly assigned to either the control (commercial concentrate + rice straw) or the treatment (commercial concentrate + rice straw + 20 g of RPML/head/day) group. The average daily gain (ADG) and feed conversion ratio (FCR) were not different between the treatment and control group. The rib eye area was slightly but not significantly higher in the treatment group than in the control group. The back fat thickness decreased with the RPML supplementation, although not significantly, and the appearance of yield C grade was lower in the treatment group than in the control group. The marbling score was similar between the control and treatment groups. The supplementation of RPML had no effect on the physicochemical compositions, myoglobin values, Commission Internationale de $l^{\prime}{\acute{E}}clairage$ (CIE) color values, fatty acid composition, and thiobarbituric acid reactive substances (TBARS) values in the longissimus muscle. Thus, the supplementation of RPML does not any negative effects on the growth performance, carcass characteristics, and meat properties of late fattening Hanwoo steers.

• Journal of Animal Science and Technology
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• v.60 no.12
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• pp.30.1-30.11
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• 2018

Background: Recently, as production costs have been increasing owing to rising feed prices worldwide, shortening the age of slaughter has been recognized as a way to increase farm income. In Korea, the raising period for Hanwoo steers is over 31 months with the delay of weaning and castration stated as one of the reasons for the increase in the raising period. Thus far, studies on age of weaning and castration have been conducted individually, and there have been no studies on the combined effects of weaning and castration ages on the growth performance and carcass characteristics in Hanwoo steers. Methods: Weaning ages were calculated at 80 or 130 days of age, and castration ages were calculated at 90 days and 180 days of age. Calves were allocated to one of the four treatment groups: W80C90 (weaning at 80 days of age and castration at 90 days of age), W80C180, W130C90, and W130C180. Results: For the entire experimental period, weaning and castration ages did not significantly affect growth performance of Hanwoo steers. In addition, weaning and castration ages did not affect the overall yield and quality traits of carcass in Hanwoo steers. Conclusion: Weaning and castration ages had small effects on growth performance and carcass characteristics in Hanwoo steers. Therefore, the early weaning and castration ages are recommended to reduce the slaughter age without any negative effects on meat quality grade.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.975-984
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• 2005

This study fulfilled to investigate the feed efficiency, tissue selenium distribution, carcass characteristic and economic value in finishing Hanwoo steers fed organic selenium mix (OSM) which included seleno-yeast, rumen culture and other microbial supplements. Forty five finishing Hanwoo steers were tested for 4 months dividing to three feeding groups: OSM add as 0.5 ppm Se of DM feeds (0.5 ppm OSM), OSM enriched add as 1.0 ppm Se of DM feeds (1.0 ppm OSM) and basal diet without OSM (control). The total weight gains, the average daily gains and the feed intakes were not differ in treatments (p > 0.05). No differences (p > 0.05) were noted for hot carcass weight, loin eye area, backfat thickness, meat yield index, meat color, fat color, tenderness and maturity. However, the 1.0 ppm OSM showed better performances for feed requirement, TDN per gain, meat yield grade and meat quality grade compared to other groups. Tissue selenium distribution was increased by organic selenium feeding: higher Se concentration in liver and rump of 0.5 ppm OSM (p < 0.05), and kidney, liver, sirloin and rump of 1.0 ppm OSM (p < 0.05) than the tissues of control group. Generally, tissue selenium was the highest value in 1.0 ppm OSM and showed higher concentrate in order; kidney, liver, sirloin and rump. The income over feed cost was 1.06-fold higher in 1.0 ppm OSM than control group. In conclusion, organic selenium mix supplementation and its amounts were not influenced to feed intake, body gain and carcass characteristic but significantly increased tissue selenium. Therefore, these results suggest that finishing Hanwoo steer fed an enriched organic selenium mix with proper probiotics is able to produce “high-Se” beef as high bioavailable form as well as create a beneficial opportunity on Hanwoo farm.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.3
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• pp.223-232
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• 1998

The main experiment related to this report was undertaken to assess the effects of two rates of $Ca(OH)_2$ (0, 250 kg/10a only at establishment) and five rates of $N-P_20_5-K_20$ (0-0-0, 0-10-10, 6-15-15, 12-20-20, 24-25-20 kg/10a/year) on the pasture establishment, forage yield and quality, and vegetation etc. After this 10-year main e experiment pasture had been used to assess the effects of the above treaments on the soil characteristics in oversown hilly pasture of a grass-clover sward. soil properties of mutual ratios of exchangeable cations at d different soil depth, and the visible characteristics of soil conservation obtained are summarized as follows; 1. Compared with the properties of soil fertility and the level for the likelihood grass tetany, the mutual ratios of exchangeable cations in soils; Ca:Mg:K(% of CEC), Ca:Mg:K(K=I), $K/\sqrt{Ca+Mg}$, Mg/K, K/Mg, and Ca/Mg, were discussed at different soil depth. Before and after experiment, these ratios were generally unbalance and unsuitable, and were rather worsened in the order of Mg>Ca>K under the conditions of liming and NPK fertilization without Mg. 2. The ratios of Ca and Ca/Mg were increaby liming, whereas it of $K/\sqrt{Ca+Mg}$ was redused. The ratios of K and $K/\sqrt{Ca+Mg}$ in control and the heavy fertillization of NPK(especially N) were rather lowered than those in the low and medium fertilizations of NPK. 3. The prperties of consevation were closely related with the forage productivity/vegetation rates, as affected by liming and the application rates of NPK. In control of NPK, It was shown to be the worst soil conservation; severly eroded(3rd grade), exporsure of subsoil, redish brown in soil colour, and 18.8% of cobble and stony in covering rate. 4. The improvement of soil conservation was greatly enhanced by increasing the NPK rate. In the medium and heavy fertilizations of NPK, it was shown to be the favorable improvement of soil conservation; slightly eroded(lst grade), covered with humus layer/grass residues in surface soil, dark brown in surface soil colour, under 1% of cobble and stony in covering rate. The increasing of legume yield/vegetation rate by liming rather enhanced the soil conservation of grassland.

• Journal of Life Science
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• v.22 no.10
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• pp.1392-1398
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• 2012

This study investigated the effects of diet of different forages on growth performance and carcass characteristics of Hanwoo steers. Twenty-one Hanwoo steers were randomly allocated to three groups (fed hay, reed, and reed with rice straw) of seven steers each. Initial and final body weights of control, T1, and T2 groups were 125.5, 128.3, 128.3 kg and 697.4, 614.6, 706.7 kg, respectively. Average daily gain tended to increase in controls (0.70 kg/d) and the T2 group (0.71 kg/d) but not as much in the T1 group (0.60 kg/d); however, there was no significant difference. DMI was not significantly different among the treatment groups, but T1 was relatively lower than the other groups. For the yield traits, carcass weight was not significantly different between controls and the T2 group but was greater in the T2 group compared to the T1 group (p<0.05). Back fat thickness and rib eye area were higher in controls and T2 compared to T1; yield grade (A:B:C, %) was greater in T1 (43:57:0) compared to the other groups (control 0:71:29; T2 29:42:29). For the quality traits, fat color and texture were not significantly different among groups. However, meat color and maturity were significantly greater in T1 compared to T2 (p<0.05). Marbling score and appearance rate of over 1st meat quality grade were greater in the control and T2 groups compared to the T1 group. Based on the results, growth performance, feed utilization, and carcass traits appeared to improve when roughage containing rice straw plus reed was offered. Therefore, reed is worth considering as a roughage source for fattening Hanwoo steers.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.827-838
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• 2006

This experiment was carried out to investigate the effects of dietary vitamin E levels on carcass characteristics and vitamin E contents, fatty acid composition and lipid oxidation as indicated by thiobarbituric acid reactive substances(TBARS) of the longissimus muscle in Hanwoo steers. Forty Hanwoo steers were randomly assigned to one of four groups and fed the diet containing 200(control), 1000, 2000 or 2500 IU a(alpha)-tocopherol acetate/head/day for 3 months of last finishing period. Backfat thickness was thinner and beef fat color was whiter(P<0.05) in steers fed the vitamin E supplemented diets than those fed the control diet. But the longissimus muscle area and yield grade did not differ among treatments. Marbling score and quality grade were higher(P<0.05) in steers fed the diets containing 1000 and 2000 IU vitamin E than those fed the other diets. Vitamin E concentration in the longissimus muscle was higher(P<0.05) as the vitamin E content in diet was higher. The levels of oleic and linoleic acids in the longissimus muscle were not affected by dietary vitamin E levels. But linolenic and arachidonic acids were lower in steers fed the vitamin E supplemented diets than those fed the control diet. TBARS in the longissimus muscle was not affected by the vitamin E levels in diet until 5th day of storage but delayed muscle lipid oxidation in steers fed the vitamin E supplemented diets after 7th day of storage. Therefore according to this result, it may be concluded that steers have a higher quality grade and higher vitamin E concentration in muscle and lower in TBARS when diet contains 1000 or 2000 IU vitamin E per kg of diet.

• Journal of Animal Science and Technology
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• v.52 no.4
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• pp.305-312
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• 2010

Seventy two Hanwoo steers in final fattening period ($585.87{\pm}41.02kg$) were randomly assigned to 3 groups, LPLT (relatively low protein and low energy; CP 12%, TDN 73%), LPHT (relatively low protein and high energy; CP 12%, TDN 75%) and HPHT (relatively high protein and high energy; CP 14%, TDN 75%) in concentrate feed for 163 days in order to investigate the effects on growth performance, carcass characteristics, and longissimus dorsi muscle's chemical compositions. Rice straw was also fed as a roughage. Because ADGs were higher in LPLT and HPHT than LPHT, feed efficiencies were improved in LPLT and HPHT group (P<0.05). Feeding concentrates with different CP and TDN levels had affected to improve back fat thickness and rib eye area in HPHT group but had no effect on carcass weight and meat yield index. Carcass weight for LPLT, LPHT and HPHT were $420.75{\pm}30.56$, $417.05{\pm}32.03$ and $418.32{\pm}32.03kg$, respectively. Meat quality grade was improved in HPHT (P<0.001), because the marbling score was highest in HPHT group. Auction prices (carcass/kg) of LPLT, LPHT and HPHT group were 17,904 won, 18,094 won and 18,899 won, respectively. The percentage of animals over grade 1 appeared in LPLT, LPHT and HPHT were 79.2, 72.7 and 90.8%, respectively. The results of chemical analysis of longissimus dorsi muscle showed no difference between groups but crude fat composition tended to be higher in HPHT group (P=0.088) than the other groups. Stearic acid contents in the muscle was significantly increased in HPHT group than LPLT group (P<0.05). Myristoleic acid and oleic acid composition in HPHT group was higher than LPLT and LPHT group. These results supported the hypothesis that supplementation of higher levels of crude protein and energy in concentrates to Hanwoo steers' during final fattening period improved the growth performance and the carcass quality grade.

• Food Science of Animal Resources
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• v.27 no.3
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• pp.277-283
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• 2007

This study was conducted to determine the effect of mugwort powder supplementation on the fattening performance and carcass characteristics during a 14 month period (from 14 months to 27 months after birth) in 32 heads of fattening Hanwoo. Fattening Hanwoos were randomly assigned 4 treatments (8 heads/treatment): C-1 [(control (0%) with Hanwoo steers)], C-2 [(control (0%) with Hanwoo heifers)], T-1 (supplementation with 2.0% mugwort powder with Hanwoo steers) and T-2(supplementation with 2.0% mugwort powder with Hanwoo heifers). The final body weights for C-1, C-2, T-1 and T-2 at 27 months were 648.6kg, 623.1kg, 663.3kg and 620.7kg, respectively. The total gain and the daily gain were highest in the T-1 group (342.4 kg, 0.88 kg). Hanwoo steers were not significantly different from Hanwoo heifers. The feed intake for the C-1, C-2, T-1 and T-2 groups were 9.35 kg, 9.09 kg, 10.08 kg and 9.69 kg, with the T-1 value being highest. The feed conversion ratios were as follows: C-1 (11.28) > T-1 (11.48) > C-2 (11.52) > T-2 (12.57). The concentrations of total cholesterol, GOT, GPT, glucose and BUN in blood serum during the fattening period were higher after than before the experiment The total cholesterol, GOT and glucose after completion of the experiment were higher in the treatment groups than the control groups (p<0.05). The carcass body weight was higher in the treatment groups than the control groups. The back fat thickness was lower in the treatment groups (12.75-14.75mm) than the control groups (15.76-16.00mm), and the longissimus muscle area was higher in the treatment groups $(84.25-87.88cm^2)$ than the control groups $(84.00-85.25cm^2)$ with the highest over-all values in the T-1 group (p<0.05). The yield grade and quality grade point were higher in the treatment groups (2.02-2.50, 2.85-3.05 point, respectively) than the control groups (1.80, 2.55-2.80 point, respectively). In conclusion, the effects of feeding dietary mugwort powder to Hanwoo steers improved the ADG, carcass body weight, longissimus muscle area and quality grade.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.73-84
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• 2010

Gold and silver deposits within the Eunjeok and Sangeun mines are located in Yeongam district, Cheollanamdo-province. They are composed of vein ore bodies infilling the fractures of Cretaceous rhyolitic tuff. The Eunjeok mine have three gold and silver bearing hydrothermal veins which is infilling the fracture of rhyolitic tuff. Major ore minerals within the Eunjeok and Sangeun mines are arsenopyrite, pyrite, chalcopyrite, sphalerite and galena and minor ores are electrum, native silver and argentite. Sericitization is dominant in alteration zone and chloritization and dickitization is minor. Quartz veins in the Eunjeok and Sangeun mine have the similar paragenesis and vein textures such like breccia, crustiform, comb and vuggy morphology indicating the formation of typical epithermal environment. In order to carry out the preliminary feasibility study of mine according to the commodity and elucidate the occurrence features of mineral resources from Eunjeok and Sangeun mine, common commodity (Pb, Zn, Cu, Fe, Mo, W, Au and U), and industrial commodity (In, Re, Ga, Ge, Se, Te, Y, Eu and Sm) for 17 ore specimen were analyzed. It is tentatively thought that there is no exploitable mine for iron, lead, zinc, copper, tungsten and uranium based on the preliminary result. If the reserves are secured through the detailed prospecting in case of molybdenum and silver, it is tentatively thought that there will be exploitable deposits depending on international metal price. If we assume the vein width from 0.25 m to 2 m including alteration zone with the gold grade of 80g/t, it is inferred that the resources amount of the Eunjeok-Sangeun mines range from 6.5 to 65ton. However, as the vein structure of the Eunjeok and Sangeun mines is developed together with alteration zone, it should be estimated to include potential alteration zone in order to yield the average grade. It is needed to carry out more exploration in the near future because the reserves can be flexibly estimated according to the change of average grade considering the alteration zone.