• Asian-Australasian Journal of Animal Sciences
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• 제29권5호
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• pp.659-665
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• 2016

The effects of three different feeding systems on beef cattle production performance, rumen fermentation, and rumen digesta particle structure were investigated by using 18 Limousin (steers) with a similar body weight ($575{\pm}10kg$) in a 80-d experiment. The animals were equally and randomly divided into three treatment groups, namely, total mixed ration group (cattle fed TMR), SI1 group (cattle fed concentrate firstly then roughage), and SI2 group (cattle fed roughage firstly then concentrate). The results showed that the average daily gain was significantly higher in cattle receiving TMR than in those receiving SI1 and SI2 (p<0.05). Consumption per kg weight gain of concentrate, silage, and combined net energy (NEmf) were significantly decreased when cattle received TMR, unlike when they received SI1 and SI2 (p<0.05), indicating that the feed efficiency of TMR was the highest. Blood urea nitrogen (BUN) was significantly decreased when cattle received TMR compared with that in cattle receiving SI1 (p<0.05), whereas there was no difference compared with that in cattle receiving SI2. Ammonia nitrogen concentration was significantly lower in cattle receiving TMR than in those receiving SI1 and SI2 (p<0.05). The rumen area of cattle that received TMR was significantly larger than that of cattle receiving SI1 (p<0.05), but there was no difference compared with that of cattle receiving SI2. Although there was no significant difference among the three feeding systems in rumen digesta particle distribution, the TMR group trended to have fewer large- and medium-sized particles and more small-sized particles than those in the SI1 and SI2 groups. In conclusion, cattle with dietary TMR showed increased weight gain and ruminal development and decreased BUN. This indicated that TMR feeding was more conducive toward improving the production performance and rumen fermentation of beef cattle.

• Asian-Australasian Journal of Animal Sciences
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• 제27권1호
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• pp.46-54
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• 2014

This study was conducted to investigate the effects of eucalyptus (E. Camaldulensis) crude oils (EuO) supplementation on voluntary feed intake and rumen fermentation characteristics in swamp buffaloes. Four rumen fistulated swamp buffaloes, body weight (BW) of $420{\pm}15.0$ kg, were randomly assigned according to a $2{\times}2$ factorial arrangement in a $4{\times}4$ Latin square design. The dietary treatments were untreated rice straw (RS) without EuO (T1) and with EuO (T2) supplementation, and 3% urea-treated rice straw (UTRS) without EuO (T3) and with EuO (T4) supplementation. The EuO was supplemented at 2 mL/h/d in respective treatment. Experimental animals were kept in individual pens and concentrate mixture was offered at 3 g/kg BW while roughage was fed ad libitum. Total dry matter and roughage intake, and apparent digestibilites of organic matter and neutral detergent fiber were improved (p<0.01) by UTRS. There was no effect of EuO supplementation on feed intake and nutrient digestibility. Ruminal pH and temperature were not (p>0.05) affected by either roughage sources or EuO supplementation. However, buffaloes fed UTRS had higher ruminal ammonia nitrogen and blood urea nitrogen as compared with RS. Total volatile fatty acid and butyrate proportion were similar among treatments, whereas acetate was decreased and propionate molar proportion was increased by EuO supplementation. Feeding UTRS resulted in lower acetate and higher propionate concentration compared to RS. Moreover, supplementation of EuO reduced methane production especially in UTRS treatment. Protozoa populations were reduced by EuO supplementation while fungi zoospores remained the same. Total, amylolytic and cellulolytic bacterial populations were increased (p<0.01) by UTRS; However, EuO supplementation did not affect viable bacteria. Nitrogen intake and in feces were found higher in buffaloes fed UTRS. A positive nitrogen balance (absorption and retention) was in buffaloes fed UTRS. Supplementation of EuO did not affect nitrogen utilization. Both allantoin excretion and absorption and microbial nitrogen supply were increased by UTRS whereas efficiency of microbial protein synthesis was similar in all treatments. Findings of present study suggested that EuO could be used as a feed additive to modify the rumen fermentation in reducing methane production both in RS and UTRS. Feeding UTRS could improve feed intake and efficiency of rumen fermentation in swamp buffaloes. However, more research is warranted to determine the effect of EuO supplementation in production animals.

• Asian-Australasian Journal of Animal Sciences
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• 제14권5호
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• pp.631-639
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• 2001

Two experiments were carried out concerning the effects of urea-molasses cake (UMC) and its separate components as supplements on rumen environment, in sacco feed degradability and intake of swamp buffaloes fed rice straw, grasses or a mixture of grasses and rice straw. Experiment 1 was a change-over design with 4 animals and 6 treatments. The buffaloes were fed rice straw ad libitum, and the experimental treatments were: no supplementation (R); 700 g of the complete urea-molasses cake (RUMC); 53.2 g urea (RU); 276 g rice bran and 52.5 coconut meal (RRC); 26.6 g salt, 26.6 g bone meal and 2.1 g trace minerals (RMi); and 25 g molasses (RMo). Experiment 2 was a Latin square design with four diets and four animals. The treatments were: rice straw ad libitum and mixed grass (RG) at 2.5 g dry matter per kg live weight (LW); RG plus 700 g urea-molasses cake (RGUMC); mixed grass ad libitum (G); and G plus 700 g cake (GUMC). In both experiments the supplements were fed once daily. In Exp. 1 although the rumen pH was significantly different (p<0.05) among diets, it varied only from 6.90 to 7.06. The ruminal ammonia was also significantly (p<0.05) different among the diets with RUMC significantly higher than R. Total bacterial and protozoal counts were significantly (p<0.05) higher for the RUMC, RU, RMo and RRC diets. Total feed and rice straw intakes were highest for RUMC (p<0.05) and lowest for the RMi and RMo diets, but in sacco degradability of four different roughages were not significantly different among diets. In Exp. 2, rumen pHs of the diets differed significantly and (p<0.01) ranged from 7.04 - 7.19. Ruminal $NH_3-N$ concentrations (mg/100 ml) were also significantly different (p<0.05), and higher for the RGUMC, G and GUMC diets. The total counts of bacteria and protozoa were significantly (p<0.05) higher for the RGUMC, G and GUMC diets. The total feed intake and roughage intake were significantly (p<0.05) higher for the RGUMC, G and GUMC diets compared to the RG diet. Correspondingly, LW changes also differed among treatments (p=0.06). It was concluded that there were significant increases in rumen $NH_3-N$ concentration, microbial populations and feed intake in the buffaloes by UMC supplementation, whereas the significant difference in in sacco DM degradation was not found by any type of supplementation. There seemed to be a need of a combination of urea, molasses, minerals and other protein nitrogen sources to enhance rice straw intake. Adding grass to the rice straw diet at 0.25% LW (DM) should also be considered to maintain buffalo rumen function and production with UMC supplementation, when rice straw is the main roughage.

• Asian-Australasian Journal of Animal Sciences
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• 제20권1호
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• pp.45-51
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• 2007

A growth trial (Expt. 1) and an in vitro fermentation experiment (Expt. 2) were conducted to determine the response of growth performance, cecal fermentation characteristics and in vitro gas production to incremental levels of substitution of digestible fiber for lignified fiber in the diet of weaned rabbits. Three diets, formulated by substituting soyhulls (SH; used as digestible fiber source) for soybean straw (used as lignified fiber source) at substitution levels of 0, 25 and 50%, were used in a factorial design. In the growth trial (Expt. 1), increasing levels of SH substitution resulted in a quadratic increase in daily body weight gain rate (p<0.04) and feed conversion efficiency (p<0.02), but in a numerical decrease in dietary DM intake (p=0.15). When SH were included in the diet at 25% substitution level, rabbits had the highest rate of liveweight gain and feed conversion efficiency. As SH substitution level increased, pH values and ammonia-N of cecal contents linearly (p<0.001) decreased, but total VFA concentration linearly (p<0.03) increased. With incremental levels of SH substitution, the percentage of acetate and butyrate linearly (p<0.05) reduced, but the percentage of propionate and minor acids linearly (p<0.03) increased. Increasing the SH substitution levels tended to increase incidence of diarrhea. In the in vitro fermentation experiment (Expt. 2), regardless of origin of substrates fermented, increasing SH substitution level resulted in increased maximal gas production (p<0.001) and shortened gas production lag time, but had no effect on gas production rate (p>0.2). These observations suggest that incrementally feeding SH to rabbits could stimulate their cecal microbial activity, allowing cecal fermentation to shift towards favoring fiber digestion. In conclusion, digestible fiber from soyhulls may partially substitute for more lignified fiber, soybean straw, without having an adverse effect on cecal fermentative and microbial activity and growth performance. For growing rabbits, about 73% of total dietary NDF should be supplied by effective NDF, the remainder could come from digestible NDF, such as soyhulls.

• Asian-Australasian Journal of Animal Sciences
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• 제27권11호
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• pp.1562-1570
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• 2014

The effects of Lactobacillus mucosae (L. mucosae), a potential direct fed microbial previously isolated from the rumen of Korean native goat, on the rumen fermentation profile of brewers grain were evaluated. Fermentation was conducted in serum bottles each containing 1% dry matter (DM) of the test substrate and either no L. mucosae (control), 1% 24 h broth culture of L. mucosae (T1), or 1% inoculation with the cell-free culture supernatant (T2). Each serum bottle was filled anaerobically with 100 mL of buffered rumen fluid and sealed prior to incubation for 0, 6, 12, 24, and 48 h from which fermentation parameters were monitored and the microbial diversity was evaluated. The results revealed that T1 had higher total gas production (65.00 mL) than the control (61.33 mL) and T2 (62.00 mL) (p<0.05) at 48 h. Consequently, T1 had significantly lower pH values (p<0.05) than the other groups at 48 h. Ammonia nitrogen ($NH_3$-N), individual and total volatile fatty acids (VFA) concentration and acetate:propionate ratio were higher in T1 and T2 than the control, but T1 and T2 were comparable for these parameters. Total methane ($CH_4$) production and carbon dioxide ($CO_2$) were highest in T1. The percent DM and organic matter digestibilities were comparable between all groups at all times of incubation. The total bacterial population was significantly higher in T1 (p<0.05) at 24 h, but then decreased to levels comparable to the control and T2 at 48 h. The denaturing gradient gel electrophoresis profile of the total bacterial 16s rRNA showed higher similarity between T1 and T2 at 24 h and between the control and T1 at 48 h. Overall, these results suggest that addition of L. mucosae and cell-free supernatant during the in vitro fermentation of dried brewers grain increases the VFA production, but has no effect on digestibility. The addition of L. mucosae can also increase the total bacterial population, but has no significant effect on the total microbial diversity. However, inoculation of the bacterium may increase $CH_4$ and $CO_2$ in vitro.

• 농업과학연구
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• 제43권5호
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• pp.802-809
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• 2016

The objective of this study was to evaluate the nutritional value of commercial compound feeds for late finishing Hanwoo steers using detailed chemical analysis and an in vitro rumen fermentation trial. A total of 4 different feeds were selected and used to conduct a chemical analysis for their nutrient contents. The largest variation in nutrients contents among experimental feeds was found in ether extract and the smallest one was found in total digestible nutrients. Commercial feeds C and D had a higher energy value than the others. Even if C and D had a similar feed energy value, the components used to increase energy differed between them (non-fiber carbohydrate [NFC] for C; ether extract for D). In the in vitro trial, no significant difference was observed in dry matter in vitro digestibility and gas production between treatments. However, the highest ammonia concentration (p < 0.05) was observed in C and D feeds. The low acetate to propionate ratio observed in C feeds (p < 0.01) suggested that this feed had high starch based carbohydrates that NFC degrading bacteria used to produce more propionate. It is important to provide nutritional information to farmers so that they can select the appropriate commercial feeds to suit their own feeding strategies. This study might give supporting information to farmers for a more educated, and better, selection of feeds. Further in vivo studies should be conducted to evaluate the effects of different commercial feeds on growth performances in late finishing Hanwoo steers.

• 생명과학회지
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• 제28권3호
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• pp.351-356
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• 2018

L-세린 탈수화효소(LSD)는 L-serine을 피루브산과 암모니아로 전환하는 반응을 촉매하는 iron-sulfur 함유 효소이다. 세균성 아미노산 탈수화 효소 중에서, L-serine에 대한 이들 특정 효소만이 촉매 부위에서 iron-sulfur cluster를 이용하는 것으로 보고되고 있다. 또한, 세균성 LSD는 구조적 특성과 도메인의 배열에 따라 네 가지 유형으로 분류된다. 현재까지, 이 효소들은 소수의 균주로부터 얻어진 LSD 효소에 대해서만 연구되었지만, 다양한 세균성 LSD의 촉매 메커니즘을 이해하기 위해서는 더 많은 자세한 조사가 요구된다. 본 연구에서, Mycobacterium tuberculosis H37Rv로부터 유래된 유형 II LSD (MtLSD) 단백질을 효소 동력학적 방법을 이용하여 생화학적 및 촉매적 특성을 규명하기 위해 발현 및 정제되었다. MtLSD에 대한 L-serine의 포화 곡선은 알로스테릭 협동성(allosteric cooperativity)을 나타내는 전형적인 S자형(sigmoid)의 특성을 보였다. 이때의 $K_m$과 $k_{cat}$ 값은 각각 $59.35{\pm}1.23mM$과 $18.12{\pm}0.20s^{-1}$로 계산되었다. 또한, 고정된 L-serine 농도 하에서 D-serine의 농도 대비 초속도에 대한 그래프는 비선형 쌍곡선 감쇠 형태를 보였고, $k_{cat}$ 값의 변화 없이 $30.46{\pm}5.93mM$의 겉보기 $K_i$ 값으로 D-serine에 대한 경쟁적 억제(competitive inhibition)를 나타내었다. 이들 연구는 MtLSD의 촉매 특성 및 기질 특이성에 관한 통찰력 있는 생화학적 정보를 제공한다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권6호
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• pp.797-803
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• 2017

Objective: Effects of nitrogen supplementation associated with different levels of starch on voluntary intake, digestibility, and rumen and metabolic characteristics of cattle fed low-quality tropical forage (Brachiaria decumbens hay, 7.4% crude protein, CP) were evaluated using ruminal and abomasal cannulated steers. Methods: Five European${\times}$Zebu young bulls (186 kg body weight, BW) were distributed according to a $5{\times}5$ Latin square. The following treatments were evaluated: control, supplementation with 300 g CP/d (0:1), supplementation with 300 g starch/d and 300 g CP/d (1:1), supplementation with 600 g starch/d and 300 g CP/d (2:1), and supplementation with 900 g starch/d and 300 g CP/d (3:1). A mixture of nitrogenous compounds provided 1/3 from true protein (casein) and 2/3 from non-protein nitrogen (mixture of urea and ammonium sulphate, 9:1) was used as the nitrogen supplement. In order to supply energy a unique source of corn starch was used. Results: Supplements increased (p<0.05) dry matter intake, but did not affect (p>0.05) forage intake. There was a cubic effect (p<0.05) of starch on voluntary intake. This was attributed to the highest forage intake (g/kg BW) when using the 2:1 starch:CP ratio. Supplements increased (p<0.05) organic matter (OM) digestibility, but did not affect (p>0.05) neutral detergent fibre corrected for ash and protein (NDFap) digestibility. There was a positive linear effect (p<0.05) of the amount of starch supplemented on OM digestibility. Total NDFap digestibility was not affected (p>0.05) by the amount of supplemental starch. Ruminal ammonia nitrogen concentrations were higher (p<0.05) in supplemented animals, however, a negative linear effect (p<0.05) of amount of starch was observed. Supplements increased (p<0.05) the nitrogen balance (NB) and efficiency of nitrogen utilization. These effects were attributed to increased body anabolism, supported by higher (p<0.05) serum concentration of insulin-like growth factor 1. Increasing the amount of starch tended (p<0.06) to linearly increase the NB. In spite of this, there was a highest NB value for the 2:1 starch:CP ratio amongst the treatments with supplementation. Conclusion: Nitrogen supplementation in cattle fed low-quality tropical forage increases nitrogen retention in the animal's body. An additional supply of starch increases nitrogen retention by increasing energy availability for both rumen and animal metabolism.

• 한국토양비료학회지
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• 제18권1호
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• pp.105-110
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• 1985

신개간간척답토양(新開墾干拓畓土壤)에서 볏짚 및 석고시용시(石膏施用時) 토양중(土壤中) Urease활성(活性), 초산(硝酸) 및 아초산환원효소활성(亞硝酸還元酵素活性)에 미치는 영향(影響)을 알고저 실내(室內) 시험(試驗)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 간척답토양(干拓畓土壤)의 Urease활성(活性)은 일반답토양(一般畓土壤)에 비(比)하여 1/10정도(程度)로 낮고 담수초기(湛水初期)보다 담수후기(湛水後期)에 높았으며 볏짚시용(施用)은 석고시용구(石膏施用區)보다 Urease 활성(活性) 증가효과(增加效果)가 높았다. 2. 초산환원효소활성(硝酸還元酵素活性)은 삼요소구(三要素區)에 비(比)하여 석고(石膏) 및 볏짚시용(施用)으로 증대(增大)되었으며 그 효과(效果)는 볏짚보다 석고시용(石膏施用)으로 더욱 증대(增大)되었다. 그러나 볏짚과 석고병용시(石膏倂用時)는 효소(酵素)의 활성(活性)이 현저(顯著)히 감소(減少)되었다. 3. 아초산환원효소(亞硝酸還元酵素)의 활성(活性)은 담수초기(湛水初期) 볏짚과 석고시용(石膏施用)으로 현저(顯著)히 증대(增大)되었으며 볏짚과 석고병용효과(石膏倂用效果)는 볏짚단용구(單用區)와 비슷한 결과(結果)를 보였다. 4. 토양중(土壤中) 효소활성간(酵素活性間)의 관계(關係)를 보면 Urease활성(活性)과 Ammonia농도간(濃度間)에는 정상관관계(正相關關係)($r=0.550^*$) Urease활성(活性)과 아초산환원효소활성간(亞硝酸還元酵素活性間)에는 부상관관계(負相關關係)($r=0.555^*$) 그리고 초산환원효소(硝酸還元酵素)와 아초산환원효소간(亞硝酸還元酵素間)에는 정상관관계(正相關關係)($r=0.296^*$)를 보였다. 5. 볏짚과 석고시용시(石膏施用時) 토양중(土壤中) 초산(硝酸)과 아초산(亞硝酸)의 생성(生成)은 토양미생물(土壤微生物)의 산화(酸化) 및 환원작용(還元作用)에서 First Order Kinetic에 의한 효소반응식(酵素反應式)으로 밝혀졌다.

• 농업과학연구
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• 제34권2호
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• pp.143-150
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• 2007

본 연구는 항생제를 대체할 목적으로 동물체의 활성을 가져오는 원료로 알려져 있는 활성탄과 목초액, sodium bentonite, 홍삼박, 생균제를 선별하여 이들 원료로 구성된 항생물질 대체제를 개발하여 홀스타인 수송아지에 급여하였을 때 생산성에 미치는 효과를 규명하고자 수행하였다. 송아지의 일당증체량은 대조구(1.01kg), 처리구(1.01kg)간에 유의적인 차이가 없었고(P>0.05), 사료 요구율은 대조구 3.24에 비하여 처리구 2.80로 처리구에서 유의적인 개선효과를 나타냈다(P<0.05). 설사 발생률은 동일하였으나 분 상태는 처리구가 양호하였고, 호흡기 질병은 처리구에서는 발생하지 않았다. 분 중 $NH_3$ 농도는 대조구(6.33 ppm)에 비하여 처리구(2.67 ppm)에서 뚜렷한 개선 효과를 보였고(P<0.05), 혈액 수치는 대조구와 처리구가 유사하였다. 항생물질 대체제를 급여한 처리구가 시판 항생제 첨가사료 급여군(대조구)에 비하여 증체에서는 다소 낮은 성적을 나타냈지만 질병 발생 없이 유사한 성적을 낸 것은 대체물질이 가축 소화기관의 활성화, 사료의 소화율 증진 등에 영향을 나타내어 동물의 활력이 증진되므로 항생제의 사용 없이도 양질의 축산물을 생산할 수 있는 결과를 얻었다.