• Journal of Animal Science and Technology
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• 제46권4호
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• pp.701-706
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• 2004

본 연구는 2001년 3월부터 2001년 12월까지 충남대학교 농업생명과학대학내 부속 초지시험포장에서 하번초형 혼파초지 {Turf type mixtures: Kentucky bluegrass(Newport) 40%+tall fescue(Rebell Jr.) 20%+perennial ryegrass(Palmer II) 10%+redtop(Barricuda) 10%+red fescue(Salem) 10%+creeping bentgrass(Crenshaw) 10%}에서 수확한 1번초(4월 24일)의 목초와 상번초형 혼파초지 {tall type mixtures:orchardgrass(Potomac) 40%+tall fescue(Fawn) 20%+Festulolium braunii(Paulita) 10%+perennial ryegrass(Feveille) 10%+timothy(Climax) 10%+red clover(Kenblue) 5%+alfalfa(Vemal) 5%}에서 수확한 1번초(4월 24일)를 공시하였다. 시험축은 한국재래산양을 8두를 공시하여 건물소화율, 건물섭취량, 질소 및 에너지 이용성을 비교 분석하였으며, 얻어진 결과는 다음과 같다. 1) 건물섭취량은 하번초형 초지(28.9g/BW,kg/day)가 상번초형 초지(26.2g/BW,kg/day)에 비하여 다소 높은 편이었으나 유의적인 차이는 없었다. 세포내용물질(cellular constituents)의 소화율은 하번초형 초지가 높은 편이었으나(P<0.05), DM, NDF 및 ADF 소화율은 두 초지간에 유의적인 차이가 인정되지 않았다. 2) 외관상 생물가는 하번초형 초지(56.7%)가 상번초형 초지(56.4%)보다 높은 편이었으나 유의적인 차이는 인정되지 않았다. 3) 외관상 대사에너지 축적률은 하번초형 초지(58.3%)가 상번초형 초지(57.9%)보다 높은 편이었으나 유의적인 차이는 인정되지 않았다. 이상의 결과로 보아, 재래산양에 의한 하번 초형 목초의 이용성은 상번초형 초지에서 생산된 목초와 비교할 때 큰 차이가 없는 것으로 나타나 조사료원으로 이용가능성은 충분하다고 하겠다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권11호
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• pp.1629-1634
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• 2008

A trial was conducted to determine the effect of low crude protein (CP) diets with constant metabolizable energy to crude protein (ME:CP) ratio on growth, body composition and nutrient utilization of broiler chicks from 1 to 26 days of age. Four dietary treatments having four levels of CP and ME as 23, 22, 21 and 20% and 3,036, 2,904, 2,772 and 2,640 kcal/kg, respectively, were formulated and a ME:CP ratio of 132 was maintained in all the diets. Digestible lysine was maintained at 1.10 of the diet. A total of 1,760 day-old Hubbard broiler chicks were randomly divided into 16 experimental units and each diet was offered to four experimental units at random. Feed intake was increased (p<0.05) while weight gain and feed conversion ratio were adversely affected (p<0.05) when the diets with low CP and ME were fed to broilers. Total protein intake and total ME intake were linearly decreased (p<0.05) and protein efficiency ratio and energy efficiency ratio were lower (p<0.05) than in the chicks fed dietary regimen with 22% CP and 2,904 kcal/kg ME. The whole body analysis of the birds revealed that chicks fed the lowest dietary regimens retained less (p<0.05) nitrogen and more ether extract than chicks fed the control diet, however, body dry matter, total body ash and fat free body protein were not affected. Similarly, protein and energy utilization were also unaffected by the dietary treatments. In summary, chicks fed low CP diets with constant ME:CP ratio grew slower, used feed less efficiently and retained less protein and more body fat than chicks fed the control diet.

• 한국해양환경ㆍ에너지학회지
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• 제16권1호
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• pp.25-35
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• 2013

실내실험과 현장관측을 통해서 용존태무기질소(dissolved inorganic nitrogen; DIN) 제한 하에서 유독와편모조류 Alexandrium tamarense와 A. catenella의 생존과 우점화 전략을 살펴보았다. 현장관측결과 마산만에서 Alexandrium 속이 출현하는 기간동안 DIN이 식물플랑크톤의 성장 제한영양염으로 나타났다. 성장동력학 실험으로부터 도출된 질산염의 Ks값은 현장에서 우점하는 규조류보다 A. tamarense와 A. catenella가 높아, 영양염 경쟁에 있어 불리한 위치에 있는 것으로 나타났다. 하지만 A. tamarense와 A. catenella는 DIN 제한하에서 요소나 아미노산과 같은 용존유기질소 (dissolved organic nitrogen; DON) 화합물을 성장에 이용하였다. 따라서 마산만과 같이 Alexandrium 속이 출현하는 봄~여름까지 DIN이 제한영양염으로 작용하는 환경에서 DON의 흡수능력은 이들 종이 성장을 유지하는데 큰 역할을 할 뿐만 아니라 종의 우점과정 및 종간 경쟁에서도 중요한 영향을 줄 것으로 보인다.

• KSBB Journal
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• 제13권4호
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• pp.391-398
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• 1998

The effect of culture medium copper availability on the specific growth rate(${\mu}$) and carbon conversion efficiency (CCE) was sutided for an obligatory methanotroph Methylosinus trichosporium OB3b under various combinations of carbon and nitrogen sources. Methane or methanol was used as a carbon source, and nitrate or ammonium was used as a nitrogen source. Medium copper availability determined the intracellular location or kind of methane monooxygenase (MMO), cell-membrane (particulate or pMMO) when copper was present and cytoplasm (soluble or sMMO) when copper was deficient. When methane was used as a carbon source, copper-containing medium exhibited higher ${\mu}$ and CCE than copper-free medium regardless of the kind of nitrogen source. When methanol was used as a carbon source, however, the effect of copper disappeared. Ammonium gave the higher ${\mu}$ and CCE than nitrate for both methane and methanol. Those observation suggest that there exist an important difference in energy utilization efficiency for methane assimilation between sMMO and pMMO.

• 한국축산식품학회지
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• 제36권1호
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• pp.109-113
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• 2016

This study aimed to examine the nutrient utilization of rump round meat and lotus root using young (32 wk) and aged hens (108 wk) as an animal model. Rump round meat and lotus root were prepared with or without enzymatic treatment. For each age group of laying hens, a total of 24 Hy-Line Brown laying hens were randomly allotted to one of two dietary treatments with six replicates. For rump round meat, the true total tract retention rate (TTTR) of dry matter (DM) and nitrogen (N) were unaffected by either enzymatic treatment or hen age. However, aged hens had greater (p<0.01) TTTR of energy and crude fat than young hens. Enzymatic treatment did not influence the TTTR of energy or crude fat. In addition, we did not observe any significant interaction between the TTTR of DM, energy, N, or crude fat in rump round meat and hen age or enzymatic treatment. The TTTR of DM remained unchanged between controls and enzyme-treated lotus root for young hens. However, enzyme-treated lotus root exhibited greater (p<0.05) TTTR of DM than control lotus root for aged hens, resulting in a significant interaction (p<0.05). The TTTR of energy and N in lotus roots were greater (p<0.01) for aged hens than for young hens. In conclusion, enzymatic treatment exerted beneficial effects on energy and nutrient utilization in aged hens, suggesting the aged hen model is practical for simulation of metabolism of elderly individuals.

• Asian-Australasian Journal of Animal Sciences
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• 제19권1호
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• pp.91-96
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• 2006

The experiment was conducted to study the effect of choice feeding on growth performance, carcass quality, gastrointestinal development and feed utilization of 22-49 days old broilers. One hundred and forty four 22-day-old broilers were randomly allocated to 3 treatments with 4 replicates per treatment and 12 birds per replicate. Three feeding regimes are complete diet (control), ground corn and protein concentrate (treatment I), and soybean meal and balancer (treatment II). Protein concentrate is the residue part of complete diet without corn, and balancer is the residue part of complete diet without soybean meal. Treatment I and II are designed for the broilers to freely choose the two parts of diet. The results showed that: (1) broilers under choice feeding (treatment I and II) had lower performances compared with the control; (2) gastrointestinal development and the efficiency ratios that broilers converted dietary crude protein and lysine to body weight gain were improved in treatment I (p<0.05); (3) there were no significant differences in the apparent metabolizabilities of dietary dry matter, crude protein and gross energy, and deposition ratios of dietary nitrogen and energy, and carcass quality among three feeding regimes (p>0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.207-212
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• 1994

Effects of dietary cellulose and protein levels on nutrient utilization in chickens were investigated. Four experimental diets containing 5% (low cellulose) or 20% (high cellulose) cellulose in combination with 10% (low protein) or 20% (high protein) protein of 70 g/day were alternatively forced-fed to eight colostomized White Leghorn cockerels once a day to make $4{\times}4$ Latin-square design. The digestibilities of DM and energy decreased with the increase in cellulose level, but not affected by dietary protein level. Ether extract digestibility was higher in the high cellulose diets than in the low cellulose protein level. Ether extract digestibility was higher in the high cellulose diets than in the low cellulose diets. The digestibility of nitrogen free extract had the same trend with the digestibility of DM and energy. The digestibility of acid detergent fiber was not so much different among the diets, but the NDF digestibility was lower in the high cellulose diets than in the low cellulose diets, due to the low hemicellulose digestibility. The true digestibility of protein was influenced by both of the dietary protein and cellulose levels, and their interaction was found. The dietary protein level affected the biological value of protein but the dietary cellulose level did not, and consequently the biological value of protein in the low protein diets was lower than in the high protein diets.

• Journal of Animal Science and Technology
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• 제62권5호
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• pp.659-667
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• 2020

This study was conducted to evaluate the effects of different levels of crude protein (CP) and protease on nitrogen (N) utilization, nutrient digestibility, and growth performance in growing pigs. A total of six crossbred ([Landrace × Yorkshire] × Duroc) barrows were individually accepted in 1.2 m × 0.7 m × 0.96 m stainless steel metabolism cages. The pigs (average initial body weight of 27.91 ± 1.84 kg) randomly assigned to six diets with six weeks (6 × 6 Latin square design). The experiment was carried out in an environment with a temperature of 23 ± 1.5℃, a relative humidity of 83 ± 2.3% and a wind speed of 0.25 ± 0.03 m/s. The dietary treatments were arranged in a 2 × 3 factorial design with two levels of CP (15.3% or 17.1%) and three levels of protease (0 ppm, 150 ppm, or 300 ppm). The average daily gain and gain to feed ratio (G:F) tended to increase (p = 0.074) with increasing amounts of protease. The low CP level diet reduced (p < 0.050) urinary and fecal N concentrations, the total N excretion in feces, and increased (p < 0.050) N retention. Different protease levels in the diet did not affect (p > 0.05) at N intake, but supplementation of the diets with 300 ppm protease decreased (p < 0.050) the N concentration in urine and feces and tended to increase (p = 0.061) the percentage of N retention retained of the total N intake. The dietary CP level did not affect (p > 0.050) the apparent total tract digestibility (ATTD) of dry matter, digestible energy (DE), and metabolic energy (ME), but diet supplementation with 300 ppm protease showed higher (p < 0.050) ATTD of DE and ME than in the protease-free diet. Therefore, a low protein diet with protease could improve the utilization of nitrogen, thereby reducing the negative effect of N excretion into the environment while maintaining or increasing growth performance compared to a high protein diet.

• Journal of Microbiology and Biotechnology
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• 제23권6호
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• pp.794-801
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• 2013

This paper reports the production and characterization of crude xylanase from the newly isolated Humicola sp. Ly01. The highest (41.8 U/ml) production of the crude xylanase was obtained under the optimized conditions (w/v): 0.5% wheat bran, 0.2% $KH_2PO_4$, and 0.5% peptone; initial pH 7.0; incubation time 72 h; $30^{\circ}C$; and 150 rpm. A considerable amount of the crude xylanase was induced using hulless barley bran or soybean meal as the carbon source, but a small amount of the enzyme was produced when supplementary urea was used as the nitrogen source to wheat bran. The crude xylanase showed apparent optimal cellulase-free xylanase activity at $60^{\circ}C$ and pH 6.0, more than 71.8% of the maximum xylanase activity in 3.0-30.0% (v/v) ethanol and more than 82.3% of the initial xylanase activity after incubation in 3.0-30.0% (v/v) ethanol at $30^{\circ}C$ for 2 h. The crude xylanase was moderately resistant to both acid and neutral protease digestion, and released 7.9 and 10.9 ${\mu}mol/ml$ reducing sugar from xylan in the simulated gastric and intestinal fluids, respectively. The xylooligosaccharides were the main products of the hydrolysis of xylan by the crude xylanase. These properties suggested the potential of the crude enzyme for being applied in the animal feed industry, xylooligosaccharides production, and high-alcohol conditions such as ethanol production and brewing.

• Asian-Australasian Journal of Animal Sciences
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• 제14권6호
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• pp.785-790
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• 2001

Twelve indigenous male goats, comprising of six intact and six castrated (2.5-3 years; $24.4{\pm}0.62kg$) were assigned evenly into two dietary treatments, viz. $I_0$ and $I_{100}$ and were used to study the effect of supplementation of iodine on the nutrient utilization when their diet contained Leucaena leaf meal. They were offered a conventional concentrate mixture along with Leucaena leucocephala leaf meal, the latter to meet 50% of their crude protein (CP) requirements, and supplemented with either no iodine ($I_0$) or 0.1 mg of iodine ($I_{100}$)/day/animal as potassium iodide for a period of 105 days. Wheat straw given ad libitum was the sole source of roughage. A metabolism trial of 8 days duration was conducted after 90 days of experimental feeding. It was observed that the overall dry matter (DM) intake during experimental period was higher (p<0.05) in $I_{100}$ group as compared to $I_0$ group (508.6 vs. $443.7g\;d^{-1}$). The intake of CP, digestible crude protein (DCP) and metabolisable energy (ME), although non-significant, tended to be higher in the iodine supplemented group, $I_{100}$. Digestibility of dry matter, organic matter (OM), CP, ether extract and crude fiber (CF) did not differ (p>0.05) between the treatments. However, nitrogen retention was higher (p<0.01) in $I_{100}$ than $I_0$ with the values being 2.63 and $1.70g\;d^{-1}$, respectively. No difference (p>0.05) was evident in the retention of calcium and phosphorus between the two groups. The castrated animal exhibited lower DM intake concurrent with higher digestibility of DM and crude fibre (p<0.05), and organic matter and total carbohydrates (p<0.01) when compared to intact ones. It was concluded that supplementation of iodine to leucaena based ration may help in improving the DM intake and nitrogen utilization by goats.