• 한국식품영양과학회지
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• 제32권8호
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• pp.1270-1277
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• 2003

두유박과 옥분 혼합물의 압출성형물을 제조하기 위한 공정 조건의 위하여 스크류 속도 150∼250 rpm, 혼합물의 수분함량 20∼30%, 온도 100∼15$0^{\circ}C$의 조건에서 압출 성형하고, 반응표면분석법 (RSM)을 이용하여 최적 조건을 분석하였다. 공정 조건에 따른 팽화율에서는 스크류 속도가 높고 수분함량이 낮을수록 팽화가 크게 일어났고, 수분함량이 많을수록 용적 밀도를 높이는 것으로 나타났다. 절단강도의 경우 수분 함량에 따라 감소하다 증가하는 추세를 보여주었고, WSI는 스크류 속도와 수분함량에 WAI는 수분함량과 온도에 많은 영향을 받았다. 색도에서는 b＊ 값을 제외하고는 유의적인 차이를 보이지 않았다. 각 조건별 실험결과를 반응표면분석을 한 결과 팽화율과 용적 밀도, WSI, b＊ 값은 linear모델로 결정되었고, 절단강도와 WAI는 quadratic 모델이 유의성을 나타내었다. 압출 성형 공정의 최적화는 결정된 반응식과 반응표면 그래프를 이용한 결과 수치 최적화에서는 스크류 속도 250 rpm, 수분함량 22.43%, 온도 128.16$^{\circ}C$이었고, 모형적 최적화에서는 desirability가 0.727인 스크류 속도 250 rpm, 수분함량 22.43%, 온도 128.02$^{\circ}C$로 결정되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권8호
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• pp.1093-1097
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• 2004

This study was aimed to establish the amount of enzose (corn dextrose) for optimum N fixation in urea treated corncobs (UTC) and their dietary effect on nutrient intake, digestibility and milk yield in crossbred cows. Corncobs were treated with 5% urea and ensiled in laboratory silos with 0, 2, 4 and 6% enzose for 15 days. Total nitrogen (N), neutral detergent fiber (NDF) and neutral detergent insoluble N contents were increased in UTC with the level of enzose. Five early lactating crossbred cows (Sahiwal$\times$Holstein Frisian) were used in a 5$\times$5 Latin Square Design to see the influence of UTC ensiled with 6% enzose on nutrient intake, digestibility, milk yield and its composition. Five iso-nitrogenous and iso-caloric diets were formulated. The UTC30 (control), UTC40, UTC50, UTC60 and UTC70 diets contained 30% UTC ensiled without enzose and 40, 50, 60, 70% UTC ensiled with 6% enzose, respectively. Dry matter, NDF and ADF intakes were increased with the increasing level of UTC ensiled with enzose in the diets of cows. Dry matter, NDF and ADF digestibilities were significantly higher with diets containing UTC ensiled with enzose. Milk yield was significantly higher in cows fed UTC70 compared to those fed on other diets. The milk crude protein percentage was significantly different across treatments. However, milk fat, total solids, solid not fat, true protein and non-protein nitrogen contents of milk remained similar across all diets. Ensilation of UTC with 6% enzose improved the nitrogen retention and thus enhanced the feeding value of UTC for lactating cows.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.319-323
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• 2005

This study is concerned with development of efficient culture methods for lactic acid fermentation of Lactobacillus sp. RKY2. The cell-recycle repeated batch fermentation using cheese whey and corn steep liquor as raw materials was tried in order to further enhance the productivity of lactic acid. In addition, fermentation efficiencies could be considerably enhanced by cell-recycle continuous culture. Through the cell-recycle repeated batch fermentation, lactic acid productivity was maximized to 6.34 $g/L{\cdot}h,$ which corresponded to 6.2 times higher value than that of the batch fermentation. During the cell-recycle continuous fermentation, the last dry cell weight at the end of fermentation could be increased to 25.3 g/L.

• 한국축산식품학회지
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• 제30권3호
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• pp.512-517
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• 2010

본 연구는 전통당류식품인 엿 제조시 발생하는 엿밥에 대한 영양가치 평가와 착유우에서의 유량 및 유조성분에 미치는 영향을 규명하고자 실시하였다. 엿밥은 잔류하는 효소 및 당도 함량이 높고, 단백질과 지방 함량이 옥수수 글루텐에 필적 할 만큼 영양적 가치가 우수한 것으로 나타났다. 착유우에게 완전배합사료 형태로 엿밥을 1, 3 및 6% 급여하였을 때 고능력우군(평균유량 31.3 kg)에서는 대조구에 비해 유량 증진 효과가 인정되었으며, 엿밥 3% 군에서는 유지율도 증가하였다(p<0.05). 저능력우군(평균 유량 18.9 kg)에서도 엿밥 1 및 6% 첨가군에서 유량이 증가하였으며(p<0.05) 엿밥 3%군에서는 유단백질 함량도 증가하였다(p<0.05). 그러므로 우유 생산 시 엿밥의 적극적인 활용은 축산식품을 보다 저렴하게 공급하는데 도움이 될 수 있을 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권11호
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• pp.1721-1728
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• 2007

An in vitro and a feeding trial were conducted to investigate the effect of xylanase supplementation on the feeding value of growing pig diets containing high proportions of Chinese double-low rapeseed meals (DLRM). Seven diets were formulated to meet NRC (1998) nutrient requirements. Diet 1 based on corn-soybean meal was used as positive control 1, and diet 2, a practical diet which incorporated a conventional level of Chinese DLRM (60 g/kg diet), as positive control 2. Diet 3 contained a higher level of DLRM (100 g/kg diet) as the negative control. Diet 3 plus xylanase at 0.10, 0.25, 0.50 and 0.70 g/kg diet created diets 4, 5, 6 and 7, respectively. The seven diets were incubated in triplicate with the in vitro two-stage enzyme incubation method to predict responses of diets to xylanase in terms of digestibility of dry matter (DM), crude protein (CP) and neutral detergent fibre (NDF). In vitro, the negative control had the lowest CP and NDF digestibility. Both DM and CP digestibility were increased (p<0.05) owing to xylanase supplementation either at 0.50 or 0.70 g/kg diet, and NDF digestibility was improved following xylanase addition at all of the test levels. There was a high linear correlation ($r^2>90$, p<0.05) between the activity concentration of the enzyme when transformed into its logarithmic value and in vitro digestibility coefficients of DM, CP or NDF. In the feeding trial, 112 crossbred pigs were randomly assigned to seven dietary treatments with 16 replicate pens of one pig each. An obvious dose effect on growth rate was observed ($r^2=0.79$, p<0.05) within the inclusion levels of xylanase. Compared with the negative control, xylanase addition at 0.70 g/kg diet resulted in significantly increased ADG (878 g/d vs. 828 g/d, p<0.05), and a tendency towards improved growth rate (868 g/d vs. 828 g/d, p = 0.10) was also observed following the inclusion of xylanase at 0.50 g/kg diet. It would appear that the nutrient utilization of corn and Chinese DLRM diets by pigs could be enhanced by an appropriate amount of xylanase addition. The in vitro and in vivo results suggested that the in vitro incubation method is feasible for predicting responses of pigs to exogenous enzymes and identifying those preparations that possess potential for improvement of the nutritive values of feedstuffs.

• Asian-Australasian Journal of Animal Sciences
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• 제23권12호
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• pp.1601-1607
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• 2010

Two experiments were carried out to investigate i) the effects of four levels of lactic acid bacteria inoculants (LAB; 0, $2{\times}10^5$, $3{\times}10^5$ and $4{\times}10^5$ cfu/g fresh forage) and two physical forms of rice straw (whole and chopped rice straw) on silage fermentation quality and nutritive value of rice straw (RS) silage for lactating Holsteins and ii) the effects of the replacement of corn silage (CS) with different inclusion levels (0, 25 and 50%) of LAB treated RS on lactating performance of Holstein dairy cows. Rice straw packed with stretch film was ensiled for 45 d. The results showed that the higher level of LAB inoculants in the silage quadratically decreased pH, $NH_3$-N and acetic acid concentrations and increased the contents of lactic acid and total organic acids. The CP content and DM losses in the silage declined linearly as the level of LAB addition was increased. Compared with whole-plant rice straw silage (WRS), chopped rice straw silage (CRS) dramatically reduced pH by 0.83. The concentrations of $NH_3$-N were similar in WRS and CRS and both were less than 50 g/kg of total N. Chopping rice straw before ensiling significantly enhanced the lactic acid concentration and total organic acids content whereas the concentration of acetic acid declined. The CP, NDF and ADF content of CRS was 13.4, 5.9 and 10.2% lower than in WRS, respectively. Except for butyric acid concentration, significant interaction effects of inoculation level and physical form of RS were found on all fermentation end-products. Our findings indicated that milk yield and composition were not affected by different level of RS inclusion. However, because of the lower cost of WRS, cows consuming a ration in which WRS was partially substituted for CS had 3.48 Yuan (75% CS+25% WRS) and 4.56 Yuan (50% CS+50% WRS) more economic benefit over those fed a CS-based ration. It was concluded that the chopping process and LAB addition could improve the silage quality, and that substitution of corn silage with RS silage lowered the cost of the dairy cow ration without impairing lactation performance.