• Korean Journal of Environmental Biology
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• v.22 no.2
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• pp.247-258
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• 2004

Climatological, hydrological and planktonical research studies, measurements of primary production and photosynthetic efficiency from December 1976 to December 1978 have been carried out in two brackish lakes: Lake Etang de Berre and Lake Etang de Vaine located in the French Mediterranean coast, in the region of Carry-le-Rouet located on the north-west Mediterranean near Marseilles, and in fresh water inflows from 4 Rivers (Touloubre, Durance, Arc, Durancole) to Lake Etang de Berre. Physico-chemical parameters were measured for this study: water temperature, salinity, density, pH, alcalinity, dissolved oxygen (% saturation), phosphate, nitrate, nitrite, silicate etc. Diverse biological parameters were also studied: photosynthetic pigments, phaeopigments, specific composition and biomass of phytoplankton, primary pelagic production etc. Climatical factors were studied: air-temperature, solar-radiation, evaporation, direction (including strength) of winds, precipitation and freshwater volume of the four rivers. The changes in Lake ‘Etang de Berre’ ecosystem depend on the quality of the water in the Durance River, and on the effects of seawater near the entrance of the Caronte Canal. The water quality of the lake varies horizontally and vertically as a result of atmospheric phenomena, maritime currents and tides. The distribution of water temperatures is generally heterogeneous. Southeasterly winds and the Northeasterly Mistral wind are important in the origins of circulated and mixed water masses. These winds are both frequent and strong. They have, as a result, a great effect on the water environment of Lake Etang de Berre. In theory, the annual precipitation in this region is well over eight times the water mass of the lake. The water of the Durance River flows into Lake Etang de Berre through the EDF Canal, amounting to 90% of the precipitation. However, reduction of rainfall in dry seasons has a serious effect on the hydrological characteristics of the lake. The temperature in the winter is partially caused by the low temperature of fresh water, particularly that of the Durance River. The hydrological season of fresh and brackish water is about one month ahead of the hydrological season of sea water in its vicinity. The salinity of Lake Etang de Berre runs approximately 3$\textperthousand$, except at lower levels and near the entrance to the Caronte Canal. However, when the volume of the Durance River water is reduced in the summer and fall, the salinity rises to 15$\textperthousand$. In the lake, the ratio of fresh water to sea water is six to one (6:1). The large quantities of seston conveyed by rivers, particularly the Durance diversion, strongly reduce the transparency in the brackish waters. Although the amount of sunshine is also notable, transparency is slight because of the large amount of seston, carried chiefly by Tripton in the fresh water of the Durance River. Therefore, photosynthesis generally occurs only in the surface layer. The transparency progressively increases from freshwater to open seawater, as mineral particles sink to the bottom (about 1.7kg $m^{-2}a^{-1}$ on the average in brackish lakes). The concentration of dissolved oxygen and the rate of oxygen saturation in seawater (Carry-le-Rouet) ranged from 5.0 to 6.0 $m\ell$ㆍ.$1^{-1}$, and from 95 to 105%, respectively. The amount of dissolved oxygen in Etang de Berre oscillated between 2.9 and 268.3%. The monographs of phosphate, nitrate, nitrite and silicate were published as a part of a study on the ecology of phytoplankton in these environments. Horizontal and vertical distributions of these nutriments were studied in detail. The recent diversion of the Durance River into Lake Etang de Berre has effected a fundamental change in this formerly marine environment, which has had a great impact in its plankton populations. A total of 182 taxa were identified, including 111 Bacillariophyceae, 44 Chlorophyceae, and 15 Cyanophyceae. The most abundant species are small freshwater algae, mainly Chlorophyceae. The average density is about $10^{8}$ cells $1^{-1}$ in Lake Etang de Berre, and about double that amount in Lake Etang de Vaine. Differences in phytoplankton abundance and composition at the various stations or at various depths are slight. Cell biovolume V (equivalent to true biomass), plasma volume VP (‘useful’ biomass) and, simultaneously. the cell surface area S and S/V ratio through the measurement of cell dimensions were computed as the parameters of phytoplankton productivity and metabolism. Pigment concentrations are generally very high on account of phytoplankton blooms by Cyanophyceae, Chlorophyceae and Cryptophyceae. On the other hand, in freshwaters and marine waters, pigment concentrations are comparatively low and stable, showing slight annual variation. The variations of ATP concentration were closely related to those of chlorophyll a and phytoplankton blooms only in marine waters. The carbon uptake rates ranged between 38 and 1091 mg$Cm^{-2}d^{-1}$, with an average surface value of 256 mg; water-column carbon-uptake rates ranged between 240 and 2310 mg$Cm^{-2}d^{-1}$, with an average of 810, representing 290 mg$Cm^{-2}$, per year 45 000 tons per year of photosynthetized carbon for the whole lake. Gross photosynthetic production measured by the method of Ryther was studied over a 2-year period. The values obtained from marine water(Carry-le-Rouet) ranged from 23 to 2 337 mg$Cm^{-2}d^{-1}$, with a weighted average of 319, representing about 110 gCm$^{-2}$ per year. The values in brakish water (Etang de Berre) ranged from 14 to 1778 mg$Cm^{-2}d^{-1}$, with a weighted average of 682, representing 250 mg$Cm^{-2}$ per year and 38 400 tons per year of photosynthesized carbon for the whole lake.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.3
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• pp.131-140
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• 2015

To set up unicellular cyanobacterial strains with photo-biological $H_2$ production potential, live samples were repeatedly collected from 68 stations in the coastal zone of Korea for the four years since 2005. Among 77 cyanobacterial strains established six (KNU strains, CB-MAL002, 026, 031, 054, 055 and 058) were finally chosen as the excellent strains for $H_2$ production with $H_2$ accumulation over 0.15 mL $H_2\;mL^{-1}$ under general basic $H_2$ production conditions as well as positive $H_2$ production for more than 60 hr. To explore optimum procedures for higher $H_2$ production efficiency of the six cyanobacterial strains, the inter-strain differences in the growth rate under the gradients of water temperature and salinity were investigated. The maximum daily growth rates of the six strains ranged from 1.78 to 2.08, and all of them exhibited $N_2-fixation$ ability. Based on the similarity of the 16S rRNA sequences, all the test strains were quite close to Cyanothece sp. ATCC51142 (99%). The six strains, however, were grouped into separate clades from strain ATCC51142 in the molecular phylogeny diagram. Chlorophyll- a content was 3.4~7.8% of the total dried weight, and the phycoerythrin and phycocyanin contents were half of those in the Atlantic strain, Synechococcus sp. Miami BG03511. The growth of the six strains was significantly suppressed at temperatures above the optimal range, $30{\sim}35^{\circ}C$, to be nearly stopped at $40^{\circ}C$. The growth was not inhibited by high salinities of 30 psu salinity in all the strains while strain CB055 maintained its high growth rate at low salinities down to 15 psu. The euryhaline strains like CB055 might support massive biotechnological cultivation systems using natural basal seawater in temperate latitudes. base seawater. The biological and ecophysiological characteristics of the test strains may contribute to designing the optimal procedures for photo-biological $H_2$ production by unicellular cyanobacteria.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.1-14
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• 2024

High soil salinity is the most severe threat to global rice production as it causes a significant decline in rice yield. Here, we investigated the effects of various plant extracts on rice plant stress associated with high salinity. Additionally, we examined various physiological and biochemical parameters such as growth, photosynthetic activity, chlorophyll content, and lipid peroxidation - in rice plants after treatment with selected plant extracts under salt stress conditions. Of the 11 extracts tested, four - soybean leaf, soybean stem, moringa (Moringa oleifera), and Undaria pinnatifida extracts - were found to effectively reduce salt stress. A reduction of only 3-23% in shoot fresh weight was observed in rice plants under salt stress that were treated with these extracts, compared to the 43% reduction observed in plants that were exposed to stress but not given plant extract treatments (control plants). The effectiveness varied with the concentration of the plant extracts. Water content was higher in rice plants treated with the extracts than in the control plants after 6 d of salt stress, but not after 4 d of salt stress. Although photosynthetic efficiency (Fv/Fm), electron transport rate (ETR), and the content of pigments (chlorophyll and carotenoid) varied based on the types and levels of stress and the extracts that the rice plants were treated with, generally, photosynthetic efficiency and pigment content were higher in the treated rice compared to control plants. Reactive oxygen species (ROS), such as superoxide radicals, hydrogen peroxide (H₂O₂), and malondialdehyde (MDA), increased as the duration of stress increased. ROS and MDA levels were lower in the treated rice than in the control plants. Proline and soluble sugar accumulation also increased with the duration of the stress period. However, proline and soluble sugar accumulation were lower in the treated rice than in the control plants. Generally, the values of all the parameters investigated in this study were similar, regardless of the plant extract used to treat the rice plants. Thus, the extracts found to be effective can be used to alleviate the adverse effects of stress on rice crops associated with high-salinity soils.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.257-267
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• 1997

Fruit bodies similar to the Phellinus sp. residing on the mulberry were collected at Yang-yang in Kang-won-do province and one strain of Phellinus sp. was isolated from the fruit bodies. For mass production of the isolated mycelia in a submerged culture, the culture conditions, medium composition, and the effect of various culture systems on the mycelial growth, were investigated. The morphological characteristics of the fruit body were as follows: covered with blackish to black and rough, lower surface with yellowish-brown to dull-brown and smooth, 5-7 cm thick and hard woody. Also, the pure cultured mycelia showed yellowish-brown color, capability of purplish-brown pigment production on the PDA plate media, no-formation of clamp-connection, much binding branch, and enzyme activities such as laccase, tyrosinase and peroxidase. Therefore, pure cultured strain was identified to be Phellinus sp. In the flask culture, the optimum culture conditions for the mycelial production were obtained after cultivation of 8 days at inoculum level of 5%(v/v), media volume of 70 mL, 150 rpm, initial pH 6, and temperature of $30^{\circ}C$. Optimum medium composition from the response surface analysis were determined to be glucose 12.12 g/L, sucrose 12.12 g/L, yeast extract 11.15 g/L, malt extract 11.15 g/L, $KH_2PO_4$ 0.855 g/L and $CaCl_2$ 0.855 g/L. The production of the mycelia after 4 and 8 days of cultivation was 1.95 and 9.89 g/L, respectively. The maximum specific growth rate and productivity were $0.020\;hr^{-1}$ and 1.25 g/L/day, respectively. Among the three different culture systems for the growth of mycelia, the maximum mycelial dry weight of 7.5 g/L was obtained after cultivation of 4 days in the air-lift fermentor under aeration rate of 2.5 vvm. The maximum specific growth rate and productivity were $0.033\;hr^{-1}$ and 1.9 g/L/day, respectively, which were about 1.7 and 4.2 times higher than those of flask culture.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.598-604
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• 2007

The current study was conducted to evaluate carcass characteristics, objectives and sensory meat qualities of Hanwoo longissimus muscle as affected by ultimate pH. Twenty-four steers and bulls ($556{\pm}53$ kg and $0.63{\pm}0.32$cm for live weight and backfat thickness, respectively) were used. As there was a linear relationship (r = 0.77) between lean meat color and ultimate pH, cattles were thus segregated into normal $pH{\leq}5.8$, Normal, n = 13) and DFD (pH>5.8, n = 11) groups. Normal pH group had significantly (p<0.05) higher carcass weight, marbling score and backfat thickness than those for high pH group, while fat color and lean meat color were inverse. In principle component analysis for co-ordinates of DFD and normal meats, fat color, lean meat color, texture, time to pH 6.2 and pH at 24 h postmortem were associated with the positive range of the first factor (67.5%) while backfat thickness marbling score and temperature at 24 h were placed in negative values. The rate constant of decline in pH (pH k) did not differ between the two groups, implying that initial pH (i.e., pH at slaughtering) differed between two groups. Contour mapping of pH k between pH at 1 and 24 h postmortem indicated that high pH k was related to lower pHs at 1 and 24 h postmortem. This suggested that the high pH cattles (i.e., DFD cattle) resulted from their own potential. Although the time to reach pH 6.2 was significantly (p<0.05) shorter for normal meat (i.e., 3.2 h) than that for DFD one (i.e., 19.8 h), there were no significantly differences in both WB-shear force and sensory attributes. Given that the experimental animals were sampled from a similar group, which implies a similar myoglobin pigment content, the current data suggested that pre- and post-slaughter animal handling likely had a significant effect on ultimate pH and consequently meat color of Hanwoo longissimus muscle, and also small animals with lower marbling score and backfat thickness had a higher risk for DFD meat.

• Korean Journal of Food Science and Technology
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• v.19 no.2
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• pp.113-118
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• 1987

An intermediate moisture model food system was used to investigate the effects of water activity (Aw), temperature, pH and polyethyleneglycol (PEG) on the Maillard reaction. The initial molar ratio of glucose to lysine was varied from one half to four. The maximum Maillard reaction was obtained from an initial glucose/lysine molar ratio of approximately three. The rate of Maillard reaction showed a maximum in the range of water activity of a normal intermediate moisture food. 'the model food system was prepared to hold water activity range of 0.47-0.84 and the samples were held at various temperatures. The maximum browning rate occurred at an Aw value of approximately 0.89 at $40^{\circ}C$ and $60^{\circ}C$, 0.74 at $30^{\circ}C$ and 0.67 at $20^{\circ}C$, respectively. The Arrhenius activiation energies for nonenzymatic browning pigment production were 18.03, 15.18 and 9.90 Kcal/mole for the sample with Aw 0.84, 0.74 and 0.67. When the pH of the model system was increased, a significant increase in the browning reaction was observed. On the inhibitive effects of PEG, the higher degree of polymerization, the more inhibition of browning reaction.

• Journal of Life Science
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• v.21 no.10
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• pp.1377-1384
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• 2011

Astaxanthin (ATX) is a red-orange carotenoid pigment that occurs naturally in a wide variety of living organisms. In this study we investigated the inhibitory effects of ATX on the induction of inducible nitric oxide synthase (iNOS), nitric oxide (NO), proinflammatory cytokines, nuclear factor-kappa B(NF-${\kappa}B$) and reactive oxygen species (ROS) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. In addition, we tested the superoxide radical scavenging activity of ATX by scavenging assay. iNOS and NF-${\kappa}B$ expressions were determined by immunoblot analysis. Interleukin (IL)-6 and tumour necrosis factor-${\alpha}$ (TNF-${\alpha}$) were assayed by ELISA. NO production was monitored by measuring the amount of nitrite. ROS was examined by using the 2', 7'-Dichlorodihydrofluorescin diacetate (DCFH-DA) method. At a concentration of 100 ${\mu}M$, ATX inhibited the expression level of LPS-induced NF-${\kappa}B$, as well as the production of LPS-induced NO and proinflammatory cytokines (IL-6 and TNF-${\alpha}$), by suppressing iNOS expression. In particular, the maximal inhibition rate of IL-6 and TNF-${\alpha}$ production by ATX (100 ${\mu}M$) was 65.2----- and 21.2-----, respectively. In addition, ATX inhibited the LPS-induced transcriptional activity of NF-${\kappa}B$, and this was associated with suppressing the translocations of NF-${\kappa}B$ from the cytosol to the nucleus. Moreover, at various concentrations (25-100 ${\mu}M$), ATX inhibited the intracellular level of ROS. At a concentration of 5 mg/ml, the superoxide radical scavenging activity of ATX was 1.33 times higher than ${\alpha}$-tocopherol of the same concentration. These results showed that ATX inhibited the expression of iNOS and the production of NO and proinflammatory cytokines resulting from ROS production and NF-${\kappa}B$ activation in macrophages. Furthermore, ATX was found to be more effective in superoxide radical scavenging activities compared to ${\alpha}$-tocopherol. These findings are expected to strengthen the position of ATX as anti-inflammatory medicine and antioxidant.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.10-10
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• 2017

Rice consumption has been continuously decreasing as the eating habits of Koreans have become westernized and diversified. The per capita annual rice consumption in Korea has dropped sharply from 136.4 kg in 1970 to 61.9 kg in 2016. The Korean government, therefore, has been trying to promote rice consumption by invigorating the processed food industry using rice flour. To facilitate the market for processed rice foods, it is essential to develop proper milling technology in terms of flour particle size and damaged starch content to produce high quality rice flour at competitive cost. Dry milling and wet milling are the two major processes used to produce rice flour. Although the dry milling process is relatively simple with a lower production cost, damaged starch content increases because of the high grain hardness of rice. In wet milling, the quality of rice flour is improved by reducing flour particle size as well as damaged starch content through soaking procedures. However, the production costs are high because of the additional expenses associated with the disposal of waste water, sterilization and drying of the wet flour. Recently developed technologies such as jet milling and cryogenic milling also require expensive investment and production. Therefore, developing new rice cultivars with dry milling adaptability as well as good processing properties is an important goal of rice breeding in Korea. 'Suweon 542' is a floury endosperm mutant line derived from sodium azide treatment on a high-yield, early maturing, and non-glutinous japonica rice cultivar, 'Namil'. Compared with the wild type, after dry milling process, the grain hardness of 'Suweon 542' was significantly lower because of its round and loosely packed starch granules. Also, the flour of 'Suweon 542' had significantly smaller particles and less damaged starch than 'Namil' and other rice cultivars and its particle size distribution was similar to a commercial wheat cultivar. Recently, through collaborations with nine universities and food companies, a total of 21 kinds of processed prototypes, using the dry milling flour of 'Suweon 542', were evaluated. In the production of major rice processing products, there was no significant quality difference between the flours prepared by wet milling and dry milling. Although the amount of water added to the dough was slightly increased, it was confirmed that the recipe applying the wet flour could be used without significant change. To efficiently transfer the floury endosperm characteristics of 'Suweon 542' to other commercial rice cultivars, it is essential to develop DNA marker tightly linked to the target gene. Association analysis using 70 genome-wide SSR markers and 94 F2 plants derived from 'Suweon 542'/'Milyang 23' showed that markers on chromosome 5 explained a large portion of the variation in floury grains percentage (FGP). Further analysis with an increased number of SSR markers revealed that the floury endosperm of 'Suweon 542' was directed by a major recessive locus, flo7(t), located in the 19.33-19.86 Mbp region of chromosome 5, with RM18639 explaining 92.2% of FGP variation in the F2 population. Through further physical mapping, a co-segregate and co-dominant DNA marker with the locus, flo7(t) was successfully developed, by which, thereby, breeding efficiency of rice cultivars having proper dry milling adaptability with high yield potential or useful functional materials would be improved. 'Suweon 542' maintained the early maturity of the wild type, Namil, which can be used in rice-wheat double cropping systems in Korea not only for improved arable land but also for sharing flour production facilities. In addition to the high susceptibility against major rice diseases, nevertheless, another possible drawback of 'Suweon 542' is the high rate of viviparous under prolonged rainfall during the harvesting season. To overcome susceptibility and vivipary of 'Suweon 542', the progeny lines, derived from the crosses 'Suweon 542' and 'Jopyeong', an early maturing rice cultivar with multiple resistance against rice blast, bacterial blight, and rice strip virus, and 'Heugjinju', a anthocyanin pigment containing black rice cultivar, were intensively evaluated. As the outputs, three dry milling suitable rice elite lines, 'Jeonju614', 'Jeonju615', and 'Jeonju616' were developed.

• Korean Journal of Environmental Biology
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• v.30 no.3
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• pp.210-218
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• 2012

The morphological characteristics, carbon and nitrogen concentrations, stable isotope values and photosynthetic rates of Porphyra yezoensis were studied at the main purple lavers production areas on southwestern coast of Korea. The morphological characteristics of leaf length, leaf width and weight of Porphyra blades were between 11.6~16.3 (average 13.8) cm, 4.6~6.3 (average 5.4) cm, $1.1{\sim}2.6(average\;1.86)g\;DW\;m^{-2}$, respectively. Photosynthetic pigment of Chl a concentration of Porphyra blades was between $2.18{\sim}17.77(average\;9.65)mg\;DW\;Chl\;a\;m^{-2}$. Carbon and nitrogen concentrations of Porphyra blades was between $201{\sim}317(average\;240)mg\;DW\;g^{-1}$, $39.8{\sim}50.0(average\;43.5)mg\;DW\;g^{-1}$ and C/N ratio 5.0~6.7 (average 5.5). The range of average ${\delta}^{13}C$ and ${\delta}^{15}N$ values of Porphyra blades was between - 25.6 to - 24.0 (average - 24.7)‰ for ${\delta}^{13}C$, and 1.3 to 4.1 (average 2.1)‰ for ${\delta}^{15}N$. Photosynthetic characteristics of seaweeds measured by pulse amplitude modulation (PAM) fluorometry was used as an indicator of photosynthetic activity. We use Diving-PAM fluorometry to examine photosynthetic rates of the seaweeds Porphyra yezoensis at each station. Maximum quantum yield of Porphyra blades was between 0.46~0.55 (average 0.52), the variance of the effective PS II maximum quantum yield of the station was broadly similar. Maximum relative electron transport rate (rETRmax) of Porphyra blades was between $4.71{\sim}5.84(average\;5.33){\mu}mol\;electrons\;m^{-2}\;s^{-1}$, the changes of maximum relative electron transport rate (rETRmax) of Porphyra yezoensis were similar to those of PS II maximum quantum yield. Photosynthetic efficiency (${\alpha}$) was between 0.027~0.045 (average 0.036). Minimum saturating irradiance ($E_k$) range was $139{\sim}180(average\;156){\mu}mol\;photons\;m^{-2}\;s^{-1}$. Minimum saturating irradiance ($E_k$) made a difference by station within the area on southwestern coast. Carbon and nitrogen concentrations and photosynthetic rates of Porphyra blades production areas on southwestern coast were broadly similar. The photosynthetic characteristics showed low photosynthetic rates because the low maximum quantum yields and low maximum relative electron transport rate.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.1
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• pp.72-79
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• 2006

1,225 healthy day-old avian broiler chicks were used to investigate the effects of activated charcoal (AC, made from willow tree), hydrated sodium calcium aluminosilicates (HSCAS) and esterified glucomannan (EGM) supplementation on broiler performance, blood profiles and meat characteristics when less moldy or moldy corn was included to formulate seven isocaloric and isonitrogenous diets: Positive Control (less moldy corn diet, PC), PC+2% AC, Negative Control (moldy corn, NC), NC+0.05% EGM, NC+0.1% EGM, NC+0.5% HSCAS and NC+1% AC. PC+2% AC resulted in lower growth rate, poorer feed conversion ratio (FCR), more leg problems and higher mortality of birds than those fed PC diet (p<0.05). Inclusion of 0.05% EGM, 0.1% EGM, 0.5% HSCAS and 1% AC in NC diet did not improve average daily weight gain (ADG) or affect feed intake of birds during the first or the second three-week periods. However, 0.05% EGM tended to (p>0.05) and 0.1% EGM significantly (p<0.05) improved FCR during the first three-week period. Breast meat of NC birds had higher Minolta $L^*$ values (white) but lower $a^*$ (reddish) and $b^*$ (yellowish) values (p<0.01) than the PC birds. Addition of 0.05% EGM and 0.1% EGM in NC diet reduced the $L^*$ values (p<0.05), improved $a^*$ and $b^*$ values (p<0.05) of breast meat of birds fed NC diet, but had no effect on meat color when 0.5% HSCAS or 1% AC was included (p>0.05). Relative weight of liver to body was reduced by feeding NC diet (p<0.05) and could not be normalized by different mycotoxin adsorbents (p>0.05) to the ratio of the PC birds. Relative weight of cholecyst of NC birds was increased compared with PC birds and could only be normalized by addition of 0.05% EGM and 1% AC (p<0.05) in NC diet. NC birds had lower serum albumin level than the PC birds (p<0.05) and addition of 0.05% EGM or 1% AC in NC diet did normalize serum albumin level. Addition of 0.5% HSCAS in NC diet further reduced serum albumin, globulin, total protein and uric acid levels (p<0.05). It was concluded that lower FCR during the first three-week period of growth and deterioration of meat quality observed in bird fed moldy corn with moderate T2 and fuminisin contamination and damaged nutrients and pigment availability, might be improved by dietary supplementation of 0.05% to 0.1% EGM, but not by 1% AC or 0.5% HSCAS supplementation.