• 에너지공학
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• 제24권4호
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• pp.11-17
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• 2015

본 연구에서는 음식물류 폐기물 폐수(이하, 음폐수)를 이용하여 혐기성발효 시 부산물로 생성되는 메탄가스의 생산효율을 높이고자 산발효 전처리를 수행하였으며 전처리된 음폐수를 이용하여 BMP 실험을 통해 메탄생산량 증대를 위한 산발효 최적조건을 확인하고자 하였다. 산발효된 음폐수를 이용하여 BMP 실험을 진행한 결과 HRT 3일 조건에서 0.220 L/g VS의 가장 높은 메탄생산량을 확인하였으며, 초기 pH별 BMP실험에서는 pH 6에서 19,920 mg/L로 가장 높은 VFA와 Acetic acid/TVFA(76.2%)를 보였다. 이때 메탄생산은 약 10일 이내로 대부분 생산되어 일반적인 메탄발효(30일 이내)에 비해 약 1/3수준으로 단축됨을 확인하였다. 메탄생성량은 0.294 L/g VS로 대조군 대비 약 1.3배 높은 효율을 나타내었다.

• 농업과학연구
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• 제51권3호
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• pp.283-294
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• 2024

The objective of this study was to investigate the effect of supplementing concentrates in a forage-based diet on methane emissions of pregnant Hanwoo heifers. Twenty-one pregnant Hanwoo heifers (481 ± 42.4 kg) were divided into two groups: 1) a group receiving forage only (control, CON) and 2) the other group receiving forage with 4 kg of a concentrate mix (treatment, TRT). Methane (CH₄) concentration was measured using a laser methane detector, following an 18-d adaptation period, according to previously established protocols. Feed intake was recorded throughout the experimental period. Ruminal fluid was collected and analyzed for pH, ammonia-nitrogen (NH₃-N), and volatile fatty acid (VFA). The TRT exhibited higher dry matter and neutral detergent fiber intake than CON (p < 0.05) with elevated NH₃-N (p < 0.001) and total VFA concentrations (p = 0.013). The proportions of butyrate, valerate, and iso-valerate were higher in TRT than CON (p < 0.05). Notably, CH₄ concentrations per kg dry matter intake was lower in the TRT group, both from respiration and eructation (p < 0.05). In conclusion, supplementing concentrates in a low-quality forage-based diet for pregnant Hanwoo heifers fulfills nutrient requirements and reduces CH₄ emissions, suggesting a potential strategy to reduce environmental impact of Hanwoo production.

• Asian-Australasian Journal of Animal Sciences
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• 제13권7호
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• pp.967-973
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• 2000

A metabolism trial was conducted with 28 Najdi rams allocated into seven dietary groups to evaluate the effect of dietary inclusion of Salicornia bigelovii Torr biomass on nutrient digestibility, rumina I fluid metabolites and nitrogen and mineral balances. Either the stems (ST) or spikes (SP) of this seawater-irrigated halophyte were incorporated into complete diets at rates of 0, 10, 20 and 30% levels, replacing equal amounts of rhodesgrass hay in a ground mixed control diet. Digestibility of DM, OM, EE, NFE and fecal and urinary nitrogen were not affected by increased level of ST in the diet. As level of ST increased from 0 to 20% in the diets, CP digestibility and nitrogen retention approached their maximum (p<0.01), whereas CF digestibility reached its minimum (p<0.01). On the other hand, except for EE, digestion of all nutrients and nitrogen retention were linearly depressed (p<0.01) as SP increased in the diets from 10 to 30% level. Concentration of ammonia-N, total VFA and pH values in the rumen fluid were lower (p<0.01) with the ST- or SP-fed diets than with the control diet. Increasing level of ST or SP in the diet was associated with an increase (p<0.01) in the proportion of acetate and a decline (p<0.01) in molar percentage of propionate in the ruminal fluid. Sodium absorption increased (p<0.01) with increased ST and SP in the diets up to the 10 and 20% level, respectively, followed by constant absorption values up to the 30% level. When the level of ST in the diet gradually increased to 30%, a concomitant increased (p<0:01) in Ca and P absorption were obvious; whereas, increased level of SP in the diets from 0 to 30% resulted in noticeable (p<0.01) depression in Ca and P apparent absorption.

• Asian-Australasian Journal of Animal Sciences
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• 제16권11호
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• pp.1604-1609
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• 2003

A metabolism trial with four ruminally fistulated sheep was conducted in a $4{\times}4$ Latin square design to examine the effect of concentrate to roughage ratio (70:30 vs. 85:15) and oil source (soybean oil vs. rapeseed oil) on the ruminal fermentation pattern and $C_{18}$-fatty acids composition including trans11-$C_{18:1}$ (trans11-ODA) and cis9, trans11-18:2 (cis9, trans11-CLA) in the rumen fluid and plasma. Oil was added to the concentrate at 5% level of the total diet (DM basis) and chopped rye grass hay was fed as roughage. An increased level of concentrate (85%) within supplemented oil slightly lowered pH but increased ammonia concentration. Supplementation of rapeseed oil relatively increased pH and ammonia concentration. Higher concentrate level resulted in increased tendencies of total VFA concentration while oil source did not affect the total VFA concentration and VFA proportion. Whole tract digestibilities of DM, CP, EE, NDF and OM in diets slightly increased at higher concentrate level. Proportions of oleic acid ($C_{18:1}$) and linoleic acid ($C_{18:2}$) in the rumen fluid were influenced by the fatty acid composition of oil source but oil source did not affect the in vitro formations of trans11-ODA and cis9, trans11-CLA. Slightly increased trans11-ODA and cis9, trans11-CLA proportions, however, were observed from the sheep fed high roughage diet supplemented with both soybean oil and rapeseed oil. The $C_{18:1}$ and $C_{18:2}$ composition in supplemented oils responded to those in plasma of sheep. Effects of concentrate to roughage ratio and oil source on trans11-ODA and cis9, trans11-CLA proportions in plasma were found to be small. Proportion of cis9, trans11-CLA in plasma tended to be increased from the sheep fed high roughage diet and collection time at 9h post feeding.

• 대한환경공학회지
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• 제27권9호
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• pp.1016-1021
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• 2005

본 연구에서는 산발효 공정에 관여하는 세균들을 조사 분리하고 분리된 세균들을 이용한 VFAs의 생산효율 증가 효과를 검토하였다. 연구 결과는 다음과 같다. 음식물쓰레기 산발효 공정에서 혐기성배지를 이용하여 분리된 주요 세균은 Escherichia coli, Clostridium formicoaceticum, Clostridium butyricum, Clostridium acetobutyricum 등 12 종이며 Escherichia coli와 Clostridium spp.가 우점종을 차지하고 있는 것으로 나타났으며 VFAs 생산에 주도적 역할을 하는 것으로 판단되었다. 아세트산의 생성 효율 향상에 관한 실험에서 E. coli를 $6{\times}10^8\;cells/gTS$의 농도로 접종하였을 때 287 mg/gTS(8,176 mg/L)이 생산되었고 Clostridium formicoaceticum을 $5{\times}10^4\;cells/gTS$의 농도로 접종하였을 때 551 mg/gTS(15,715 mg/L)이 생산되어 대조군과 비교하여 3배의 높은 생산성을 보였다. 부틸산의 생산에 대한 실험에서 Clostridium butyricum을 $2.5{\times}10^5\;cells/gTS$의 농도로 접종하였을 때 214 mg/gTS(6,106 mg/L)이 생성되었고 Clostridium acetobutyricum을 $1.5{\times}10^5\;cells/gTS$의 농도로 접종하였을 때 254 mg/gTS(7,261 mg/L)이 생성되어 대조군과 비교하여 2배의 생산성을 나타내었다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권7호
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• pp.962-970
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• 2012

This study aimed to investigate the effects of ruminal infusion of garlic oil (GO) on fermentation dynamics, fatty acid (FA) profile, and abundance of bacteria involved in biohydrogenation in the rumen. Six wethers fitted with ruminal fistula were assigned to two groups for cross-over design with a 14-d interval. Each 30-d experimental period consisted of a 27-d adaptation and a 3-d sample collection. Goats were fed a basal diet without (control) or with GO ruminal infusion (0.8 g/d). Ruminal contents collected before (0 h) and at 2, 4, 6, 8, and 10 h after morning feeding were used for fermentation analysis, and 0 h samples were further used for FA determination and DNA extraction. Garlic oil had no influence on dry matter intakes of concentrate and hay. During ruminal fermentation, GO had no effects on total VFA concentration and individual VFA molar proportions, whereas GO increased the concentrations of ammonia nitrogen and microbial crude protein (p<0.05). Compared with control, GO group took a longer time for total VFA concentration and propionate molar proportion to reach their respective maxima after morning feeding. The ratio of acetate to propionate in control reduced sharply after morning feeding, whereas it remained relatively stable in GO group. Fatty acid analysis showed that GO reduced saturated FA proportion (p<0.05), while increasing the proportions of C18, t11-18:1 (TVA), c9,t11-conjugated linoleic acid (c9,t11-CLA), t10,c12-CLA, and polyunsaturated FA (p<0.05). The values of TVA/(c9,t11-CLA+TVA) and C18:0/(TVA+C18:0) were reduced by GO (p<0.05). Real-time PCR showed that GO tended to reduce Butyrivibrio proteoclasticus abundance (p = 0.058), whereas GO had no effect on total abundance of the Butyrivibrio group bacteria. A low correlation was found between B. proteoclasticus abundance and C18:0/(TVA+C18:0) (p = 0.910). The changes of fermentation over time suggested a role of GO in delaying the fermentation process and maintaining a relatively modest change of ruminal environment. The inhibitory effects of GO on the final step of biohydrogenation may be related to its antibacterial activity against B. proteoclasticus and other unknown bacteria involved.

• Asian-Australasian Journal of Animal Sciences
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• 제22권7호
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• pp.993-1004
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• 2009

Three experiments were conducted to determine the effects of non-ionic surfactant (NIS) supplementation on ruminal fermentation, nutrient digestibility and performance of beef steers fed high-roughage diets. The objective of experiment 1 was to investigate the effects of NIS supplementation on in vitro ruminal fermentation of cultures administered with corn and barley as grain substrate and rice straw and timothy hay as roughage substrate. The in vivo ruminal fermentation, nitrogen balance and digestibility of nutrients were also examined with steers fed a high-roughage diet in experiment 2. The aim of experiment 3 was to determine the responses to NIS of growing steers fed a high-roughage diet. In experiment 1, ammonia nitrogen concentration for NIS supplementation was higher (p<0.05) than for the control with all substrates. However, concentrations of total volatile fatty acid (VFA), acetate, butyrate and valerate of the incubated roughage substrates, rice straw and timothy hay, were higher (p<0.05) for NIS supplementation than for the control whereas VFA concentrations in the cultures of corn and barley were unaffected. These results indicated that effects of NIS on ruminal fermentation are diet dependent, specifically on roughage sources. In experiment 2, ruminal pH of steers supplemented with NIS was lower (p<0.05) than the control. Ruminal concentrations of ammonia nitrogen, acetate, total VFA and urinary concentrations of purine derivatives were increased (p<0.05) by NIS supplementation. In experiment 3, supplementation of NIS increased (p<0.05) intakes of total feed and corn silage, average daily gain, and feed efficiency of growing steers although they varied depending on supplementation level. Due to the roughage-specific feature of NIS effects, NIS appears to enhance ruminal fermentation of fibrous parts of feeds and, consequently, performance of steers fed a high-roughage diet.

• 한국초지조사료학회지
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• 제37권4호
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• pp.322-331
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• 2017

본 연구는 바실러스, 효모 그리고 유산균으로 발효한 다양한 주스박들과 말 분변을 첨가한 in vitro 발효 시험을 통해 pH, 건물 분해율, 암모니아성 질소, 가스 발생량, 휘발성 지방산의 변화를 조사하였다. 주스박 첨가에 따른 발효액의 pH의 범위는 6.4~7.1로 미생물 발효에 의한 소화가 정상적으로 나타났다. 48시간 후 발효액에서 $10^9CFU/m{\ell}$ 정도 미생물이 증식함에 따라 사용한 주스박들이 장내 미생물에 의한 소화작용에 유용하게 이용될 것으로 판단되었다. 건물 분해율은 배양 12시간 이후부터 증가하여 48시간째에 사과박 39.19%, 포도박 38.22%, 당근박 37.02%, 감귤박 36.2% 그리고 혼합박 34.35%로 나타났다. 암모니아성 질소의 농도는 배양 12시간까지는 전 처리구에서 $1.5mg/100m{\ell}$의 수준이었으며 배양 24시간 이후부터 급격히 증가하였다. 가스 발생량은 혼합박이 가장 낮았으며, 배양 12시간 이후부터 급격히 증가하였다. 총 VFA는 배양 24시간부터 증가하여 48시간에 가장 높았다. 본 연구결과로부터 발효 주스박은 말 in vitro 소화과정에서 적정 pH를 유지하면서 건물 분해가 진행되었고 말의 맹장과 대장에서 섬유소 분해 미생물의 작용이 활발히 이루어질 수 있음을 제시하였다.

• Journal of Animal Science and Technology
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• 제51권6호
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• pp.511-520
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• 2009

The purpose of this study was to investigate effects of increased levels of eugenol, thymol and malate on pH and the concentrations of VFA, lactate and ammonia-N during in vitro ruminal incubation. One Hanwoo beef steer (741 kg) fitted with a rumen cannula was used and fed 0.5 kg/day rice straw and 10 kg/day corn-based concentrate (ratio of concentrate to rice straw = 95 : 5 on DM basis). Three different doses of thymol, eugenol and malate were used. Treatments of the experiment were as follows: Treatments of thymol were control (1g D-glucose/40ml), T1 (1g D-glucose + 40 mg thymol/40 ml), T2 (1g D-glucose + 50 mg thymol/40 ml) and T3 (1g D-glucose + 60 mg thymol/40 ml). Treatments of eugenol were control (1g D-glucose/40 ml), E1 (1g D-glucose + 55 mg eugenol/40 ml), E2 (1g D-glucose + 65 mg eugenol/40 ml) and E3 (1g D-glucose + 75 mg eugenol/40 ml). Treatments of malate were control (1g D-glucose/40ml), M1 (1g D-glucose + 25 mg malate/40ml), M2 (1g D-glucose + 50 mg malate/40 ml) and M3 (1g D-glucose + 100 mg malate/40 ml). The results of this study showed that eugenol and thymol have improved stability of the ruminal fermentation by decreasing lactic acid concentration and increasing ruminal pH. However, it inhibited the production of total VFA, acetate and propionate. Malate also improved stability of the ruminal fermentation by decreasing lactic acid concentration and increasing ruminal pH, but it had a very little effect on ruminal lactate concentrations and pH. On the other hand, malate did not decrease the concentrations of total VFA, acetate and propionate. Therefore, at the low ruminal pH expected in high-concentrate diets, thymol, eugenol, and malate are potentially useful in Hanwoo finishing diets. Further studies are necessary for determining the effectiveness of these additives on in vivo rumen fermentation and animal performance in Hanwoo finishing steers.

• Asian-Australasian Journal of Animal Sciences
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• 제18권8호
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• pp.1147-1152
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• 2005

Two experiments were conducted to evaluate the effects of dietary Biotite V (BV) supplementation on growth performance, nutrients digestibility and fecal noxious gas content in finishing pigs. In Exp. 1, a total of eighty pigs (initial body weight 88.0${\pm}$1.35 kg) were used in a 35-d growth trial. Pigs were blocked by weight and allotted to five dietary treatments in a randomized complete block design. There were four pigs per pen and four pens per treatment. Dietary treatments included: 1) Control (CON; basal diet), 2) 200 mesh BV1.0 (basal diet+200 mesh Biotite V 1.0%), 3) 325 mesh BV1.0 (basal diet+325 mesh Biotite V 1.0%), 4) 200 mesh BV2.0 (basal diet+200 mesh Biotite V 2.0%) and 5) 325 mesh BV2.0 (basal diet+325 mesh Biotite V 2.0%). Through the entire experimental period, there were no significant differences in ADG, ADFI and gain/feed among the treatments (p>0.05). With the addition of Biotite V in diet, DM and N digestibilities were increased significantly (p<0.01). Also, Ca and P digestibilities tended to increase in pigs fed Biotite V supplemented diet (p<0.01) compared to pigs fed control diet. Supplementation of Biotite V in diet reduced the fecal $NH_3-N$ and volatile fatty acid (VFA) compared to CON treatment (p<0.01). In Exp. 2, a total of sixty four pigs (initial body weight 84.0${\pm}$1.05 kg) were used in a 35-d growth trial. Pigs were blocked by weight and allotted to four dietary treatments in a randomized complete block design. There were four pigs per pen and four pens per treatment. Dietary treatments included: 1) LP (low protein diet), 2) HP (high protein diet), 3) LP+BV (low protein diet+325 mesh Biotite V 1.0%) and 4) HP+BV (high protein diet+325 mesh Biotite V 1.0%). Through the entire experimental period, ADG and gain/feed tended to increase in HP and HP+BV treatments, however, there were no significant differences (p>0.05) among the treatments. With the addition of Biotite V in diets, digestibilities of nutrients (DM, N, Ca and P) were increased significantly (p<0.01). The addition of Biotite V in diets reduced the ammonia emissions in feces (p<0.01). Supplementation of Biotite V in diets also reduced the fecal propionic acid, butyric acid and acetic acid (p<0.01) compared to pigs fed diets without Biotite V. In conclusion, supplementation of Biotite V can increase nutrients digestibility and reduce fecal $NH_3-N$ and volatile fatty acid (VFA) concentrations in finishing pigs.