• Asian-Australasian Journal of Animal Sciences
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• 제28권10호
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• pp.1419-1426
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• 2015

This study aimed to investigate the effect of the ratio of non-fibrous carbohydrates to neutral detergent fibre (NFC/NDF) and undegraded dietary protein (UDP) on rumen fermentation and nitrogen metabolism in lambs. Four $Dorper{\times}thin-tailed$ Han crossbred lambs, averaging $62.3{\pm}1.9kg$ of body weight and 10 mo of age, were randomly assigned to four dietary treatments of combinations of two levels of NFC/NDF (1.0 and 1.7) and two levels of UDP (35% and 50% of crude protein [CP]). Duodenal nutrient flows were measured with dual markers of Yb and Co, and microbial N (MN) synthesis was estimated using $^{15}N$. High UDP decreased organic matter (OM) intake (p = 0.002) and CP intake (p = 0.005). Ruminal pH (p<0.001), ammonia nitrogen ($NH_3-N$; p = 0.008), and total volatile fatty acids (p<0.001) were affected by dietary NFC/NDF. The ruminal concentration of $NH_3-N$ was also affected by UDP (p<0.001). The duodenal flow of total MN (p = 0.007) was greater for lambs fed the high NFC/NDF diet. The amount of metabolisable N increased with increasing dietary NFC:NDF (p = 0.02) or UDP (p = 0.04). In conclusion, the diets with high NFC/NDF (1.7) and UDP (50% of CP) improved metabolisable N supply to lambs.

• Asian-Australasian Journal of Animal Sciences
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• 제28권7호
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• pp.951-957
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• 2015

Four rumen fistulated swamp buffaloes were randomly assigned according to a $4{\times}4$ Latin square design to investigate the effects of Eucalyptus (E. Camaldulensis) leaf meal (ELM) supplementation as a rumen enhancer on feed intake and rumen fermentation characteristics. The dietary treatments were as follows: T1 = 0 g ELM/hd/d; T2 = 40 g ELM/hd/d; T3 = 80 g ELM/hd/d; T4 = 120 g ELM/hd/d, respectively. Experimental animals were kept in individual pens and concentrate was offered at 0.3% BW while rice straw was fed ad libitum. The results revealed that voluntary feed intake and digestion coefficients of nutrients were similar among treatments. Ruminal pH, temperature and blood urea nitrogen concentrations were not affected by ELM supplementation; however, ELM supplementation resulted in lower concentration of ruminal ammonia nitrogen. Total volatile fatty acids, propionate concentration increased with the increasing level of EML (p<0.05) while the proportion of acetate was decreased (p<0.05). Methane production was linearly decreased (p<0.05) with the increasing level of ELM supplementation. Protozoa count and proteolytic bacteria population were reduced (p<0.05) while fungal zoospores and total viable bacteria, amylolytic, cellulolytic bacteria were unchanged. In addition, nitrogen utilization and microbial protein synthesis tended to increase by the dietary treatments. Based on the present findings, it is suggested that ELM could modify the rumen fermentation and is potentially used as a rumen enhancer in methane mitigation and rumen fermentation efficiency.

• 한국식품영양학회지
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• 제14권2호
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• pp.167-174
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• 2001

기존의 간장 담금 용수 대신에 고로쇠와 대나무 수액을 이용하여 간장을 제조하였고 90일간 숙성시키면서 유기산, 무기물, 유리당, 유리아미노산 및 질소화합물 등을 분석하였다. 90일간 숙성시킨 후 무기질의 총량을 보면 일반간장에 비해 고로쇠수액 간장에서 약 2.0배, 대나무수액 간장에서는 약 4.4배 높게 정량되었다. 무기질 중 특히 칼슘, 칼륨 및 마그네슘 함량이 높았다. 유리당은 대조구에서는 glucose와 galactose, 수액 간장에서는 상기 유리당 외 fructose와 sucrose가 검출되었고, 유기산은 butyric acid가 월등히 높았다. 유리아미노산은 재래식 간장에서는 leucine, phen-ylalanine, isoleucine, lysine 그리고 glutamic acid의 함량이 높았고, phosphoserine을 포함한 11종류의 아미노산은 숙성중 계속 증가하였다. 수액간장의 숙성 중 유리아미노산의 증감 양상은 대조시료와 유사하였다. 총질소, 아미노 질소 및 암모니아성 질소의 함량은 대조시료, 수액간장 모두 일정기간동안 증가하는 경향을 나타내었다.

• 한국식품과학회지
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• 제33권3호
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• pp.353-360
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• 2001

전통 고추장의 품질개선과 기호성 향상을 위하여 마늘과 양파를 $0{\sim}6%$ 첨가하여 고추장을 제조하고 22주간 숙성시키면서 이화학적 변화를 검토하였다. 고추장의 수분은 숙성 중에 증가하고 총질소는 감소하였다. 고추장의 pH와 적정산도의 변화는 마늘 또는 양파 첨가로 적었다. 고추장의 총당은 숙성 $2{\sim}4$주 사이에 급격히 감소하였으며, 환원당은 숙성 2주 경에 높았고 마늘 첨가량이 높을수록 숙성 후기에 환원당의 감소는 적었다. 알콜은 숙성이 진행되면서 증가하였고, 양파 첨가량이 증가할수록 증가하였다. 아미노태와 암모니아태 질소는 숙성 6주까지 증가하였으며, 마늘이나 양파의 첨가 농도가 증가할수록 아미노태 질소는 증가하였고 암모니아태 질소는 감소하였다. 고추장의 Aw는 숙성중에 근소하게 감소하였으나 점조성은 숙성 18주까지 증가하였다. Aw와 점조성은 양념류 첨가의 영향이 적었으나 색도는 이들의 첨가로 L값이 낮아지고 a 와 b 값이 높아 색상이 진해졌다. 22주간 숙성시킨 고추장의 종합적인 관능치는 마늘$2{\sim}4%$ 첨가가 양호하였다.

• 한국균학회지
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• 제28권2호
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• pp.93-96
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• 2000

완효성비료원을 혼합처리해서 배양시 0.1%와 0.5% 첨가구의 경우 잡균오염율은 나타나지 않았고 무처리에 비해서 배양일수가 약간 빨라졌고 초발이 소요일수는 $2{\sim}3$일 정도 빨라졌으며 수량성에 있어서는 수량이 모두 증가하였으나$(10{\sim}28%)$, 첨가량이 증가할수록 수량성과 생체효율성은 감소하는 경향을 보였다. 완효성비료 첨가배지의 화학성분은 첨가량이 많아질수록 총질소, 암모니아태 및 질산태 질소, 칼리, 인산등은 증가하였다. 완효성비료처리배지에서 생산된 버섯자실체의 이화학적 특성은 암모니아태 질소와 질산태 질소의 경우 무처리구 보다 낮은 경향이었으며 다른 무기성분들은 무첨가와 비슷한 경향을 보였다.

• 한국초지조사료학회지
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• 제10권3호
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• pp.164-171
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• 1990

This study was carried out to enhance the nutritional value of whole crop corn silage and the utilization of animal waste as a ruminant feedstuffs. Whole crop corn were ensiled with cage layer excreta and concentrate. Treatments included whole crop corn silage (control), 10% cage layer excreta and concentrate-corn silage (CES lo), 20% cage layer excreta and 10% concentrate-corn silage (CES 20) and 30% cage layer excreta and 10% concentrate-corn silage (CES 30). The characteristics of silage fermentation was evaluated. Digestibility and palatability of the silage were observed through the feeding trial with four male Corridale sheep. The results obtained are summarized as follows: 1. Cage layer excreta-corn silage showed higher contents of crude protein and crude ash than control silage, while crude fibre content was significantlv lower than that of control silage (P(.01). 2. Total nitrogen and ammonia nitrogen content of the cage layer excreta-corn silage was significantly (P< .01) higher than that of control, but CES 10 silage was good in quality. 3. Lactic acid content of CES 10 silage was the highest, but that of CES 20 and CES 30 silage was lower than that of control. CES 20 and CES 30 silage was lower lactic acid content and higher pH than control. Therefore Flieg's score was wrose than that of control silage. 4. The numbers of total bacteria and lactic fermentation bacteria were estimated lo7-10' and 10"1OH, respectively, and there were no significant differences among treatments. Coliform numbers were not detected with CES 10 silage while were detected lo3 per gram in CES 30 silage. 5. Digestibility of crude protein, crude fibre and ADF was improved significantly in the animals fed the cage layer excreta-corn silage compared with animals fed the control silage. DCP and TDN were the highest in the CES 10 silage. 6. The intake of daily nitrogen and dry matter per metabolic body weight was the highest in animals fed the CES 10 silage.lage.

• 한국수산과학회지
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• 제54권5호
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• pp.751-760
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• 2021

This study investigated the changes in water quality parameters and microbial colonies when ozone was applied to a semi-recirculating aquaculture system (semi-RAS) for the olive flounder Paralichthys olivaceus (500 g in average weight). Concentrations of ozone-produced oxidants (OPO) in rearing tanks were maintained at 0, 0.014, 0.025 mg/L as Cl₂ for 26 days. Except total ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, phosphate phosphorus, chemical oxygen demand, and total suspended solids decreased significantly with increasing OPO concentration in daily and weekly monitoring (P<0.05). Colony forming unit (CFU) counts of heterotrophic marine bacteria decreased in an OPO concentration-dependent manner. Overall reduction rates of microbial colonies in the treatments were 80% higher than those of the control (P<0.05). During the experiment, the OPO concentration-driven ozonation was reliably practiced without any adverse effects on the animals cultured in semi-RAS. Considering the biohazard, operating cost, and stability of ozonation, an OPO concentration of 0.014 mg/L would be sufficient to control water quality parameters and microbial colonies in a semi-RAS.

• Fisheries and Aquatic Sciences
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• 제7권2호
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• pp.76-83
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• 2004

To supply fresh and quality quarantined seafood in live seafood specialty restaurants, facilities for short-term culture or holding of live marine fish and shellfish are a necessity. In this study, the performance of a simple recirculating aquarium system for the culture and holding of marine fish was evaluated. The aquarium system consisted of a culture tank, a foam fractionator for solids removal, and a Styrofoam bead filter for nitrification and solids trapping. In the first trial, the aquarium was stocked with a total of 12 kg Korean rockfish, which were fed approximately $0.5\%$ of the total fish body weight daily. During the 2-month culture period, total ammonia nitrogen (TAN) and nitrite nitrogen $(NO_2-N)$ concentrations remained below 1mg/L and 2mg/L, respectively. The chemical oxygen demand (COD) fluctuated between 13.6 and 31.2 mg/L on selected sampling days. The total suspended solids (TSS) removed by the foam fractionator was between 2.7 and 4.6g daily. The Styrofoam bead filter not only reduced TAN and $NO_2-N$ in the culture tank water, but also trapped solids equivalent to 8.3-26.7\% of the weight of feed supplied. In Trial 2, 30kg of live fish were held in the aquarium without feeding for a 24-hour period and the water quality parameters were monitored. TAN and $NO_2-N$ concentrations first increased and then decreased to around 0.3mg/L. These results demonstrate that the recirculating aquarium system is a functional option for the short-term culture or holding of marine fish.

• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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• pp.895-900
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• 1999

The aim of this study was to evaluate the effect of incorporating wet sorghum distiller's grains (WSDG) as part of their diet on the lactating performance of dairy cows. Twenty-seven Holstein milking cows were selected, all in the early lactating stage, with an average weight of 550 kg, and producing an average of 30 kg of milk daily. The cows were divided into three groups according to milk yield and lactation and were fed different total mixed rations. The diets were formulated according to NRC (1989) recommendations in three rations to (1) control diet, (2) 15% WSDG diet and (3) 30% WSDG diet. The three different diets were all formulated as iso-nitrogen and iso-energetic diets. After one week adaptation period, the experimental feeding was conducted for 8 weeks. Three ruminal cannulated cows were also examined in order to investigate ruminal fermentation of the three total mixed rations. The results showed that the milk yield, as corrected to the 4.0% fat standard, had no significant difference among the control, 15% WSDG and 30% WSDG treatment groups (p>0.05). The daily dry matter intake of the control group was higher than the other groups (p<0.05). with respect to milk composition, milk fat, milk protein and total solids, there was no significant difference among the treatment groups (p>0.05). The energy efficiency of the 30% WSDG group were significantly higher than the other treatment groups (p<0.05). Ruminal pH value showed no difference among the treatment groups (p<0.05). Ammonia-nitrogen concentration in the control group was higher than the other treatment groups (p<0.05). The concentration of total ruminal volatile fatty acid was similar in all three dietary groups.

• 청정기술
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• 제27권1호
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• pp.61-68
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• 2021

선택적 촉매 혼합법은 대용량의 화력 발전시스템에서 질소산화물을 제거하는 방법으로 많이 사용되고 있다. 분사된 암모니아와 유입된 배기가스의 균일한 혼합은 촉매 층에서의 탈질 환원 과정에서 매우 중요하다. 본 연구에서는 탈질설비의 암모니아 분사시스템 설계과정에 전산해석 기법을 적용하였다. 적용 모델은 현재 가동되고 있는 800 MW급 석탄 화력 발전소의 탈질설비이다. 유동 해석 범위는 암모니아 분사 시스템 입구에서 촉매 층 후단부이다. 2차원 유동장을 선택하였고 비압축성으로 가정하였다. 상용 소프트웨어인 ANSYS-Fluent를 사용하여 정상 상태의 난류 유동을 해석하였다. 설계 변수로는 암모니아 분사 시스템에서의 노즐 배치 간극과 분사 유량으로 4가지 경우에 대해 결과를 분석하였다. 촉매 층 입구에서의 몰 비에 의한 평균제곱근오차 값을 최적화 변수로 선정하였고 실험계획법을 기반으로 한 최적화 알고리즘을 도입하였다. 노즐 피치와 유량을 동시에 조절한 경우가 유동 균일성 관점에서 가장 우수하였다.