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Possibility of Drought stress Indexing by Chlorophyll Fluorescence Imaging Technique in Red Pepper (Capsicum annuum L.) (고추의 엽록소 형광 이미지 분석법에 의한 한발스트레스 지표화 가능성)

  • Yoo, Sung-Yung;Eom, Ki-Cheol;Park, So-Hyun;Kim, Tae-Wan
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.5
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    • pp.676-682
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    • 2012
  • The objectives of this study focused on measuring chlorophyll fluorescence related to drought stress comparing some parameters. Almost parameters were declined although they were not significant on the basis of mean values of fluorescence of total leaf area. While the ratio of fluorescence intensity variable chlorophyll ($F_V$) to fluorescence intensity maximal chlorophyll ($F_M$) was not changed, the effective quantum yield of photochemical energy conversion in photosystemII (${\Phi}PSII$) and chlorophyll fluorescence decrease ratio ($R_{fd}$) were slightly reduced, indicating inhibition of the electron transport from quinone bind protein A ($Q_A$) to quinone bind protein B ($Q_B$). Some parameters such as non-photochemical quenching rate ($NPQ_{_-LSS}$) and coefficients of non-photochemical quenching of variable fluorescence (qN) in mid-zone of leaf and near petiole zone leaf were significantly enhanced within 4 days after drought stress, which can be used as physiological stress parameters. Decrease in ${\Phi}PSII$ could was significantly measured in all leaf zones. In conclusion, three parametric evidences for chlorophyll fluorescence responses such as ${\Phi}PSII$, NPQ, and qN insinuated the possibility of photophysiological indices under drought stress.

Physiological Responses of the Three Deciduous Hardwood Seedlings Growing Under Different Shade Treatment Regimes (상이한 피음조건에서 자라는 3개 활엽수의 생리적 반응)

  • Kim, Gil-Nam;Cho, Min-Seok;Lee, Soo-Won
    • Journal of Bio-Environment Control
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    • v.19 no.1
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    • pp.36-48
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    • 2010
  • This present study was conducted to investigate photosynthetic characteristics, chlorophyll fluorescence, chlorophyll contents of Betula platyphylla var. japonica, Prunus leveilleana, Magnolia sieboldii, growing under four different light intensity regimes (full sun, and 64~73%, 35~42%, 9~16% of full sun). As result, Betula platyphylla var. japonica showed outstanding photosynthetic capacity and apparent quantum yield in full sun and showed low shade tolerance. Prunus leveilleana showed good photosynthetic capacity and apparent quantum yield in 64~73% or 35~42% of full sun and showed common shade tolerance. However, Magnolia sieboldii showed good photosynthetic capacity and apparent quantum yield in 35~42% of full sun, while the lowest in full sun. Magnolia sieboldii showed the highest shade tolerance compared to the other species. As the shading level increased, the total chlorophyll contents of all species increased with significant difference.

A comprehensive review of microplastics: Sources, pathways, and implications (미세 플라스틱의 종합적 고찰: 근원, 경로 및 시사점)

  • Yano, K.A.V.;Reyes, N.J.D.G.;Geronimo, F.K.F.;Jeon, M.S.;Kim, Y.;Kim, L.H.
    • Journal of Wetlands Research
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    • v.22 no.2
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    • pp.153-160
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    • 2020
  • Most studies defined microplastic (MP) as plastic particles less than 5 mm. The ubiquity of MP is raising awareness due to its potential risk to humans and the environment. MP can cause harmful effects to humans and living organisms. This paper review aimed to provide a better understanding of the sources, pathways, and impacts of MP in the environment. MP can be classified as primary and secondary in nature. Moreover, microplastic can also be classified as based on its physical and chemical characteristics. Stormwater and wastewater are important pathways of introducing MP in large water bodies. As compared to stormwater, the concentrations of MP in wastewater were relatively lower since wastewater treatment processes can contribute to the removal of MP. In terms of polymer distribution, wastewater contains a wider array of polymer varieties than stormwater runoff. The most common types of polymer found in wastewater and stormwater runoff were polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE) and polyethylene terephthalate (PET). The continuous discharge and the increasing number of MP in the environment can pose greater hazards and harmful effects on humans and other living organisms. Despite the growing number of publications in relation to MP, further studies are needed to define concrete regulations and management strategies for mitigating the detrimental effects of MP in the environment.

MECHANICAL PROPERTIES OF TIN COATED FILM WITH VARIOUS COATING THICKNESS ON TITANIUM ALLOY (타이타늄 합금에 다양한 두께로 코팅된 TiN 피막의 기계적 성질)

  • Lee, Jae-Yun;Oh, Dong-Joon;Kim, Hee-Jung;Chung, Chae-Heon
    • The Journal of Korean Academy of Prosthodontics
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    • v.45 no.5
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    • pp.675-686
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    • 2007
  • Statement of problem: Titanium nitride(TiN) coatings are the most general and popular coating method and used to improve the properties of metallic surface for industrial purposes. When TiN coating applied to the abutment screw, frictional resistance would be reduced, as a results, the greater preload and prevention of the screw loosening could be expected. Purpose: The purpose of this study was to investigate mechanical properties of TiN coated film of various coating thickness on the titanium alloy surface and to evaluate proper coating thickness. Material and method: 95 Titanium alloy (Ti-6Al-4V) discs of 15 mm in diameter and 3 mm in thickness were prepared for TiN coating and divided into 7 groups in this study. Acceding to coating deposition time (CDT) with TiN by using Arc ion plating, were divided into 7 groups : Group A (CDT 30min), Group B (CDT 60min), Group C (CDT 90min), Group D (CDT 120min), Group E (CDT 150min), Group F(CDT 180min) and Group G (no CDT) as a control group. TiN coating surface was observed with Atomic Force Microscope(AFM), field emission scanning electron microscopy(FE-SEM) and examined with scratch tester, wear tester. Result: 1. Coating thickness fir each coated group was increased in proportion to coating deposition time. 2. Surface of all coated groups except Group A was homogeneous and smooth. However, surface of none coated Group G had scratch. 3. Adhesion strength for each coated group was increased in proportion to coating deposition time. 4. Wear resistance for each coated group was increased in proportion to coating deposition time. 5. Surface roughness in Group A, B, C was increased in proportion to coating deposition time. But, surface roughness in Group D, E, F was showed decreased tendency in proportion to coating deposition time. Conclusion: According to coating deposition time, mechanical properties of TiN coated film were changed. It was considered that 120 minutes coating deposition time ($1.32{\mu}m$ in coating thickness) is necessary.

Synthesis and Anaiysis of Photohnninescence Properties of $^5D_1$$^7F_1$ Transition in $LaGaO_3$:$Eu^{3+}$ Red Phosphor ($LaGaO_3$:$Eu^{3+}$형광체의 합성 및 발광 특성)

  • Kim, Kyoung Hwa;Choi, Yoon Young;Sohn, Kee Sun;Kim, Chang Hae;Park, Hee Dong;Choe, Se Young
    • Journal of the Korean Chemical Society
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    • v.44 no.5
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    • pp.453-459
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    • 2000
  • FED has deserved an intensive attentioD as a new flat panel display. The present investigationaims at undemtanding the photoluminescence and cathodoluminescent properties of hGaO$_3$: $Eu^{3+}$ phosphor bytaking into account the possibility that this phosphor could be applied for FED. In onler to investigate on.sucha detailed behavior; 8everM experimental skil18 Je conducted to the LaGaO$_3$:$Eu^{3+}$ phosphoL The excimtion srectrum artd emission spectmn were rnezsured in the UV range and then decay curve of $^5D_0$+$^7F_j$transitions\vas examined. The decay behavior of $^5D_0$ emission was anMyzed by a newly Iuoposed cross-relaxation mech-ani8In in asswiation with inteFwnter di1ffision (or migration). The cross-mlaxation from $^5D_0$ to CTB (Cha'geTransfer Band) wuld be a quite retsonable by considering the excitation spectrum. It could be also found thatthe quenching type was changed from ditfrsion controlled process to the direct quenching process -s inJeasing $Eu^{3+}$ oncntration.

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Synthesis of Binuclear Bismacrocyclic Iron(II) Complex by the Aerobic Oxidation of Iron(II) Complex of 1,4,8,11-Tetraazacyclotetradecane

  • Myunghyun Paik Suh;Gee-Yeon Kong;Il-Soon Kim
    • Bulletin of the Korean Chemical Society
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    • v.14 no.4
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    • pp.439-444
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    • 1993
  • The aerobic oxidation of the Fe(II) complex of 1,4,8,11-tetraazacyclotetradecane, [Fe(cyclam)$(CH_3CN)_2](ClO_4)_2$, in MeCN in the presence of a few drops of $HClO_4$ leads to low spin Fe(III) species [Fe(cyclam)$(CH_3CN)_2](ClO_4)_3$. The Fe(III) cyclam complex is further oxidized in the air in the presence of a trace of water to produce the deep green binuclear bismacrocyclic Fe(II) complex $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$. The Fe(II) ions of the complex are six-coordinated and the bismacrocyclic ligand is extensively unsaturated. $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$ crystallizes in the monoclinic space group $P2_1/n$ with a= 13.099 (1) ${\AA}$, b= 10.930 (1) ${\AA}$, c= 17.859 (1) ${\AA}$, ${\beta}$= 95.315 $(7)^{\circ}$, and Z= 2. The structure was solved by heavy atom methods and refined anisotropically to R values of R= 0.0633 and $R_w$= 0.0702 for 1819 observed reflections with F > $4{\sigma}$ (F) measured with Mo K${\alpha}$ radiation on a CAD-4 diffractometer. The two macrocyclic units are coupled through the bridgehead carbons of ${\beta}$-diimitie moieties by a double bond. The double bonds in each macrocycle unit are localized. The average bond distances of $Fe(II)-N_{imine}$, $Fe(II)-N_{amine}$, and $Fe(II)-N_{MeCN}$ are 1.890 (5), 2.001 (5), and 1.925 (6) ${\AA}$, respectively. The complex is diamagnetic, containing two low spin Fe(II) ions in the molecule. The complex shows extremely intense charge transfer band in the near infrared at 868 nm with ${\varepsilon}$= 25,000 $M^{-1}cm^{-1}$. The complex shows a one-electron oxidation wave at +0.83 volts and two one-electron reduction waves at -0.43 and-0.72 volts vs. Ag/AgCl reference electrode. The complex reacts with carbon monoxide in $MeNO_2$ to form carbonyl adducts, whose $v_{CO}$ value (2010 $cm^{-1}$) indicates the ${\pi}$-accepting property of the present bismacrocyclic ligand.

Molecular physiological inhibitory effects of chloroacetanilide herbicide pretilachlor on marine dinoflagellate Prorocentrum minimum (해양 와편모조류 Prorocentrum minimum에 대한 아세트아닐라이드계 제초제 프레틸라클로르의 분자 생물학적 저해 효과)

  • Hansol Kim;Jang-Seu Ki
    • Korean Journal of Environmental Biology
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    • v.39 no.4
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    • pp.452-462
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    • 2021
  • Pretilachlor (PRE) is a common acetanilide herbicide used worldwide. However, its effects on aquatic organisms, particularly marine photosynthetic life, are not sufficiently known. Herein, we evaluated the toxic effects of PRE by physiological and molecular parameters in the photosynthetic dinoflagellate Prorocentrum minimum. The cell density, pigment content, and photosynthetic parameters (Fv/Fm and PIABS) were considerably decreased with increased PRE exposure time and doses. In addition, photosynthesis-related genes, PmpsbA, PmpsaA, and PmatpB, were significantly upregulated when exposed to 1.0 mg L-1 of PRE for 24 h (p<0.001). In 72 h treatment, the relative gene expression was significantly increased (0.1 and 0.5 mg L-1; p<0.01). In contrast, PmrbcL was decreased or little changed compared to the controls. Reactive oxygen species (ROS) increased after 24 h exposure (p<0.001). However, the transcriptional fold-changes in glutathione S-transferase (GST) were significantly increased (0.5 and 1.0 mg L-1; p<0.001) at 72 h. These findings suggested that the PmGST might be involved in PRE detoxification in P. minimum. In addition, PRE may affect the photosystem function in phytoplankton similar to other acetanilides, causing severe damage or cell death.

Dramaturgische und Aufführungs-analyse von Romeo und Julia -Shakespeares Drama und Oh, Tae-suks Aufführung- (<로미오와 줄리엣>의 드라마투르기적 분석 및 공연분석 -셰익스피어의 드라마와 오태석의 공연-)

  • Lee, In-Soon
    • Journal of Korean Theatre Studies Association
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    • no.40
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    • pp.163-206
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    • 2010
  • Um die Jahrhundertwende des 20. Jahrhunderts besinnt sich Theater als ein Kunstwerk auf seine eigene $Realit{\ddot{a}}t$, $K{\ddot{o}}rper$, Raum und Zeit. Die Existenzweise des Theaterkunstwerks ist $Auff{\ddot{u}}hrung$. Die Kennzeichen der $Auff{\ddot{u}}hrung$ ist Transitorik, Unmittelbarkeit und Ereignishaftigkeit. $Auff{\ddot{u}}hrungsanalyse$ der Theaterwissenschaft als Disziplin wird lange Zeit $vernachl{\ddot{a}}ssigt$, weil $Auff{\ddot{u}}hrung$ ein Opfer der Zeit ist. Angesichts der $Auf{\ddot{u}}hrungsanalyse$ $mu{\ss}$ man eine Invariante zur $Verf{\ddot{u}}gung$ stellen, um einen Gegenstand zu analysieren. Die Inszenierung als ${\ddot{a}}sthetischer$ Gegenstand ist einmalig und unwiederbringlich. Das $B{\ddot{u}}hnengeschehen$ ist materielle $Realit{\ddot{a}}t$, die von dem Zuschauer sinnlich - optisch und akustisch - erfahren wird. Die Inszenierung realisiert sich in 'drei $B{\ddot{u}}hnengestalten$': 'Intendierte $B{\ddot{u}}hnengestalt$', 'realen $B{\ddot{u}}hnengestalt$' und 'vermeinte $B{\ddot{u}}hnengestalt$'. Die $Auff{\ddot{u}}hrung$ konkretisiert sich im Kopf des Zuschauers nicht als eine reale $B{\ddot{u}}hnengestalt$, sondern als ein '${\ddot{a}}sthetisches$ Objekt', 'als Abdruck der $B{\ddot{u}}hnenvorg{\ddot{a}}nge$'. Der Platz des $Auff{\ddot{u}}hrungsanalytikers$ ist der des Zuschauers, des Rezipienten. Die ${\ddot{a}}sthetische$ $B{\ddot{u}}hnengestalt$ ist eine Rekonstruktion der selektiven wahrgenommenden $Auff{\ddot{u}}hrung$, die der 'realen $B{\ddot{u}}hnengestalt$' ${\ddot{a}}hnelt$. Diese Rekonstruktion als neue $Sch{\ddot{o}}pfung$ des Rezipienten ist "Simulacrum", das der dem Objekt $hinzugef{\ddot{u}}gte$ Intellekt ist. Der Begriff der $Auff{\ddot{u}}hrungsanalyse$ wird Synonym $f{\ddot{u}}r$ die Interpretation als hermeneutischer $Proze{\ss}$. $F{\ddot{u}}r$ die Methode der $Auff{\ddot{u}}hrungsanalyse$ gibt es Strukturanalyse und Transformationsanalyse. Strukturanalyse geht $ausschlie{\ss}lich$ von der $Auff{\ddot{u}}hrung$ aus. Transformationsanalyse geht von der Transformation des Textes aus. $F{\ddot{u}}r$ diese Arbeit steht dramaturgische Analyse von Shakespeares Romeo und Julia als erste Grundlage. Die Handlungsentwicklung von Romeo und Julia ist klar in '$f{\ddot{u}}nf$ Akte' eingeteilt, die insgesamt aus 24 Szenen bestehen. Die Gesamthandlung von Romeo und Julia baut sich $pyramidenf{\ddot{o}}rmig$ nach dem Schema der steigenden und fallenden Handlung auf: Exposition/ Ausgangssituation (bis zur ersten Begegnung des Liebespaares auf dem Fest), erregendes Moment als Steigerung (von der Verliebtheit bis zur $Eheschlie{\ss}ung$), Wendepunkt/ Peripetie (Mercutios Tod), retardierendes Moment (Julias Scheintod) und Katastrophe (Vereinigung im Grabe). Die Handlung des $St{\ddot{u}}ckes$ gliedert sich in eine Haupt- und eine Nebenhandlung: dominierend ist die Liebeshandlung zwischen Romeo und Julia, daneben steht die Entwicklung der Fehde zwischen den Familien von Montague und Capulet; sie sind 'sich gegenseitig bedingend, steigernd, hemmend und vernichtend'. Parallelisierung und Kontrast der Figurenkonstellation werden in den jeweils sozial oder im Alter entsprechenden Figuren aus den beiden verfeindeten Familien gezeigt. Die Thematik des $St{\ddot{u}}ckes$ kommt in dem Oxymoron "loving hate" (I.1.175) zum Ausdruck. Shakespeare $l{\ddot{a}}sst$ die Liebeshandlung von Romeo und Julia in der Art der de casibus-$Trag{\ddot{o}}die$ spielen; deren Handlungsmuster ist 'dargestellt im Rad der Fortuna, das einen Menschen $emportr{\ddot{a}}gt$ und wieder $abst{\ddot{u}}rzen$ $l{\ddot{a}}sst$'. Das $St{\ddot{u}}ck$ Romeo und Julia ist eine experimentelle $Trag{\ddot{o}}die$. Es beginnt als $Kom{\ddot{o}}die$ mit $Z{\ddot{u}}gen$ einer Romanze, die sich aus dem Motiv der privaten Liebe und Heirat entwickelt. Pater Lorenzo und die Amme treten mit Lorenzos Wissen von der magischen Kraft der $Kr{\ddot{a}}uter$ und der $Geschw{\ddot{a}}tzigkeit$ der Amme $h{\ddot{a}}ufig$ in der $Kom{\ddot{o}}die$ auf. Die Handlung von Romeo und Julia erreicht mit Mercutios Tod den Wendepunkt, der die komische Welt zur tragischen umwandelt. $F{\ddot{u}}r$ die Sprache gibt es Prosa der Diener wie die Alltagssprache der einfachen Leute und zugleich Verse der Adeligen. Shakespeare verwendet eine kontrastreiche Metaphorik $f{\ddot{u}}r$ Raum und Zeit. Dreimal geschehen am Tag die $K{\ddot{a}}mpfe$ der verfeindeten Familien auf den ${\ddot{o}}ffentlichen$ $Pl{\ddot{a}}tzen$. Der Tag wirft ein Licht auf den Hass und die Gewalt. Die Nacht aber ist die $Sph{\ddot{a}}re$ der Liebe, wo Romeo und Julia ihre heimliche Verbindung verborgen halten $k{\ddot{o}}nnen$. Die Liebenden treffen sich in der Nacht und in dem ummauerten Raum. Oh, Tae-Suks "Romeo und Julia" wird in der Form des Madangguks gestaltet. Die Handlung in Oh, Tae- Suks Textfassung ist also nicht nach dem Prinzip der $Kausalit{\ddot{a}}t$ und Folgerichtigkeit zu lesen wie im Shakespeare-Drama. Wegen dem Ignorieren der $Kausalit{\ddot{a}}t$ des Handlungsablaufes und dem Fehlen der Motivation der Handlung ergibt sich hier keine individuelle psychologische Figurencharakterisierung. Die Figuren sind typisiert. Die koreanische Textfassung mit den extremen textlichen $Verk{\ddot{u}}rzungen$ und den zwei szenischen $Hinzuf{\ddot{u}}gungen$ $pr{\ddot{a}}gt$ die Inszenierung dahingehend, dass an die Stelle der Wortsprache mehr $K{\ddot{o}}rpersprache$ und szenische Bilder treten. Die langen Sprechpartien der Figuren im Shakespeare-Drama werden meistens $gek{\ddot{u}}rzt$ und $beschr{\ddot{a}}nken$ sich entweder auf Informationen ${\ddot{u}}ber$ die Situation oder zur Handlungsentwicklung. Und der Handlungsablauf erfolgt in Episoden sowie Musik, Lied und Tanz; Musik, Lied und Tanz dienen einerseits dem ${\ddot{U}}bergang$ der Szenen, sind aber andererseits auch selbst Teil des Handlungsablaufs. $W{\ddot{a}}hrend$ Shakespeare die Sprache der $W{\ddot{o}}rter$ in den Vordergrund $r{\ddot{u}}ckt$, $st{\ddot{u}}tzt$ Oh, Tae-Suk sich mehr auf die Sprache des $K{\ddot{o}}rpers$, die ja zugleich bildhaft ist. $Daf{\ddot{u}}r$ nimmt die Inszenierung Tanz und Lieder. Oh, Tae-Suks Inszenierung entwirft Shakespeares $Trag{\ddot{o}}die$ in der Form des Madangguks als Spiel und zugleich als erkennentnisorientiertes, nachdenkliches Theater $f{\ddot{u}}r$ den koreanischen Zuschauer, das dem traditionellen koreanischen Theater als Unterhaltungstheater nicht $m{\ddot{o}}glich$ ist, in dem sich das Volk von der Wirklichkeit erleichterte und sich $vergn{\ddot{u}}gte$. Oh, Tae-Suk formt das Publikum zum 'Wir' und zugleich zum 'Ich'. Mit dem Zusammensein der $v{\ddot{o}}llig$ andernen Theaterkulturen schafft der Reigisseur das hybride Theater und dadurch bildet $f{\ddot{u}}r$ die moderne koreanische Gesellschaft eine neue kulturelle $Identit{\ddot{a}}t$ heraus.

Effect of Partial Replacement of Green Grass by Urea Treated Rice Straw in Winter on Milk Production of Crossbred Lactating Cows

  • Sanh, M.V.;Wiktorsson, H.;Ly, L.V.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.4
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    • pp.543-548
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    • 2002
  • Fresh elephant grass was replaced by urea treated rice straw (UTRS) to evaluate the effects on milk production of crossed lactating cows. A total of 16 crossbred F1 cows (Holstein Friesian ${\times}$ Vietnamese Local Yellow), with a body weight of about 400 kg and lactation number from three to five, were used in the experiment. The experimental cows were blocked according to the milk yield of the previous eight weeks and divided into 4 homogenous groups. The experiment was conducted with a Latin Square design with 4 treatments and 4 periods. Each period was 4 weeks, with 2 weeks of feed adaptation and 2 weeks for data collection. The ratio of concentrate to roughage in the ration was 50:50. All cows were given constant amounts of elephant grass dry matter (DM), with ratios of 100% grass without UTRS (control treatment 100G), and 75% grass (75G), 50% grass (50G) and 25% grass (25G) with ad libitum UTRS. Daily total DM intake on 100G, 75G, 50G and 25G was 12.04, 12.31, 12.32 and 11.85 kg, and the daily ME intake was 121.6, 121.5, 119.4 and 114.3 MJ, respectively. The daily CP intake was similar for all treatments (1.85-1.91 kg). There was a difference (p<0.05) in daily milk yield between the 25G and the 100G and 75G (11.7 vs. 12.6 and 12.5 kg, respectively). Milk protein concentration was similar for all treatments, while a tendency to increased milk fat concentration following the increase of UTRS ratio was observed. The cows gained 4-5 kg body weight per month and showed first oestrus 3-4 months after calving. The overall feed conversion for milk production was not affected by ratio of UTRS in the ration. It is concluded that replacement of green grass by UTRS with a ratio of 50:50 for crossbred lactating cows is as good as feeding 100% green grass in terms of milk yield, body weight gain and feed conversion. UTRS can preferably replace green grass in daily rations for crossbred dairy cows in winter to cope with the shortage of green grass, with the ratio 1:1.

Effects of Natural Grass Forage to Concentrate Ratios and Feeding Principles on Milk Production and Performance of Crossbred Lactating Cows

  • Sanh, M.V.;Wiktorsson, H.;Ly, L.V.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.5
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    • pp.650-657
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    • 2002
  • Two experiments were conducted to evaluate the effects of forage:concentrate ratios and feeding principles on milk yield, milk composition, body weight change, postpartum oestrus and feed cost. A total of 36 crossbred F1 cows (Holstein Friesian${\times}$Local Yellow) in the 8th week of lactation were used. In each experiment, animals were divided into three groups using a randomized block design according to the milk yield of the previous eight weeks. Cows were fed 30, 50 and 70% concentrate in the diet based on DM. In experiment 1 (Fc), cows were given the same amount of DM with constant ratios of forage and concentrate within treatments. In experiment 2 (Fa), cows were given the same constant amounts of concentrate as in experiment 1 and ad libitum forage. The forage consisted of a natural grass mixture based on 5 species of grasses with high nutritive values. There was no difference in total DM intake between treatments within experiments. However, cows fed forage ad libitum had higher DM intakes compared to cows fed constant forage (1.6, 4.5 and 9.5% for cows fed 70, 50 and 30% forage, respectively). Daily milk yield of cows fed forage ad libitum was higher than that of cows fed constant forage:concentrate ratio. Within experiment, milk yield was highest for cows fed 30% DM forage, followed by cows fed 50% and then cows fed 70% forage (11.17, 10.98 and 10.71 for the 30Fc, 50Fc and 70Fc cows; 11.73, 11.16 and 10.81 kg for the 30Fa, 50Fa and 70Fa cows, respectively). Decreased forage ratio in the diets resulted in decreased milk fat content and tended to increase milk protein. Increased concentrate ratio in the diet and feeding forage ad libitum increased body weight gain. The effect of forage:concentrate ratio on postpartum oestrus was not significant. The feed cost per kg milk produced was lowest for the cows fed 70% forage. It is concluded that increased ratio of concentrate resulted in increased body weight gain, milk yield, milk protein, and decreased milk fat. Feeding forage ad libitum increased feed intake, milk yield and body weight gain. The ratio of 50% forage is more suitable for milk production and animal condition, but in terms of feed cost and under the conditions of small dairy farmers, the 70% ad libitum forage feeding is recommended.