• Asian-Australasian Journal of Animal Sciences
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• 제32권12호
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• pp.1854-1863
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• 2019

Objective: To effectively use corn stover resources as animal feed, we explored the chemical composition and in vitro digestibility of corn stover during field exposure and the fermentation characteristics of silage prepared with lactic acid bacteria (LAB) and cellulase. Methods: Corn ears including the cobs and shucks were harvested at the ripe stage. The corn stover was exposed in the field under natural weather conditions. Silages were prepared after 0, 2, 4, 7, 15, 30, and 60 d of exposure. Corn stover was chopped into approximately 1 to 2 cm lengths and then packed into 5 liter plastic silos. The ensiling density was $550.1{\pm}20.0g/L$ of fresh matter, and the silos were kept at room temperature ($10^{\circ}C$ to $25^{\circ}C$). Silage treatments were designed as follows: without additives (control), with LAB, with cellulase, and with LAB+ cellulase. After 45 d of fermentation, the silos were opened for chemical composition, fermentation quality and in vitro digestion analyses. Results: After harvest, corn stover contained 78.19% moisture, 9.01% crude protein (CP) and 64.54% neutral detergent fiber (NDF) on a dry matter (DM) basis. During field exposure, the DM, NDF, and acid detergent fiber (ADF) contents of corn stover increased, whereas the CP and water-soluble carbohydrate contents and in vitro digestibility of the DM and CP decreased (p<0.05). Compared to the control silage, cellulase-treated silage had lower (p<0.05) NDF and ADF contents. The pH values were lower in silage treated with LAB, cellulase, or LAB+cellulase, and lactic acid contents were higher (p<0.05) than those of the control. Silage treated with cellulase or LAB+cellulase improved (p<0.05) the in vitro DM digestibility (IVDMD) compared to that of the control or LAB-treated silage. Conclusion: Corn stover silage should be prepared using fresh materials since stover nutrients are lost during field exposure, and LAB and cellulase can improve silage fermentation and IVDMD.

• Journal of Animal Science and Technology
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• 제44권5호
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• pp.549-560
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• 2002

본 시험은 패스틴$^{(R)}$ 을 첨가하였을 때, in vitro 상에서 단백질 fraction과 분해율에 미치는 영향과, in vivo 상에서 반추위 성상, 미생물 군집, 암모니아태 질소 농도 및 영양소 소화율에 미치는 영향을 구명하고자 실시하였다. In vitro 실험에서는 1mm로 분쇄된 대두박을 기질로 하여 패스틴$^{(R)}$ ((주)은진인터내셔날)을 첨가하여 borate-phosphate buffer와 중성세제에서의 조단백질 분해율을 측정하였으며, exogenous enzyme (Streptomyces griseus 유래 protease)를 이용하여 39$^{\circ}C$에서 0, 2, 4, 8, 12, 48 시간동안 배양 후 조단백질 분해율을 측정하였다. 반추위 발효성상과 영양소 소화율은 반추위 fistula가 부착된 평균체중 300kg의 홀스타인 수소 4두를 이용하여 무첨가구, 패스틴$^{(R)}$ 첨가구의 두개 처리구에 2마리씩 4마리를 배치하여 측정하였다. Buffer Soluble Protein fraction은 패스틴$^{(R)}$ 첨가 수준별로 차이가 없었으나, 무첨가구에 비해 패스틴$^{(R)}$ 첨가구에서 감소하는 경향을 보였다. 단백질 분해율은 배양 0 시간대에서 4시간대까지는 처리구간 유의성이 없었지만, 12 h과 48 h에서는 패스틴$^{(R)}$ 첨가로 시험구에서 감소되었다. 용해 단백질 분해율 ‘a’는 패스틴$^{(R)}$ 시험구에서 경미하게 높은 수치를 나타내었지만, 소화 가능한 단백질 분해율 ‘a+b’는 패스틴$^{(R)}$ 시험구에서 낮은 경향을 보였다. 패스틴$^{(R)}$ 첨가로 pH와 $NH_3$- N 농도는 증가하는 경향이었으며 휘발성지방산, 미생물 수 및 enzyme activity는 감소하였고 영양소 소화율은 높았으나 유의적인 차이는 없었다.

• Asian-Australasian Journal of Animal Sciences
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• 제10권4호
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• pp.357-363
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• 1997

The effect of replacement of cotton seed meal (CSM), with various levels and sources of non-protein nitrogenous (NPN), substances on in vitro ruminal fermentation were studied. Cotton seed meal, in control ration provided nitrogen equivalent to 12.5 percent crude protein while in experimental ration was replaced at 30, 50 & 70 percent levels with urea, diammonium phosphate (DAP) and biuret, respectively. The results of incubation upto 48 hours indicated an improvement in digestibility by replacement of CSM with urea and biuret upto 50 percent protein equivalent, but not with DAP. Bacterial count from cultures containing 50% nitrogen from biuret was significantly higher than DAP, urea and CSM. Various sources of nitrogen produced $NH_3-N$ in increasing order of CSM, biuret, DAP and urea. Increasing levels of NPN resulted in progressive increase in the levels of $NH_3-N$. The levels of various NPN sources had no effect on pH. However, the pH values determined for urea and CSM were higher than biuret and DAP.

• Asian-Australasian Journal of Animal Sciences
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• 제22권4호
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• pp.534-541
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• 2009

The aim of this study was to evaluate the effects of gamma irradiation (${\gamma}$-irradiation) at doses of 15, 30 and 45 kGy on chemical composition, anti-nutritional factors, ruminal dry matter (DM) and crude protein (CP) degradibility, in vitro CP digestibility and to monitor the fate of true proteins of full-fat soybean (SB) in the rumen. Nylon bags of untreated or ${\gamma}$-irradiated SB were suspended in the rumens of three ruminally-fistulated bulls for up to 48 h and resulting data were fitted to a nonlinear degradation model to calculate degradation parameters of DM and CP. Proteins of untreated and treated SB bag residues were fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Digestibility of rumen undegraded CP was estimated using the three-step in vitro procedure. The chemical composition of raw and irradiated soybeans was similar. Results showed that phytic acid in ${\gamma}$-irradiated SB at dose of 30 kGy was eliminated completely. The trypsin inhibitor activity of 15, 30 and 45 kGy ${\gamma}$-irradiated SB was decreased (p<0.01) by 18.4, 55.5 and 63.5%, respectively. From in sacco results, ${\gamma}$-irradiation decreased (p<0.05) the washout fractions of DM and CP at doses of 30 and 45 kGy, but increased (p<0.05) the potentially degradable fractions. Gamma irradiation at doses of 15, 30 and 45 kGy decreased (p<0.05) effective degradability of CP at a rumen outflow rate of 0.05 $h^{-1}$ by 4.4, 14.4 and 26.5%, respectively. On the contrary, digestibility of ruminally undegraded CP of irradiated SB at doses of 30 and 45 kGy was improved (p<0.05) by 12 and 28%, respectively. Electrophoretic analysis of untreated soybean proteins incubated in the rumen revealed that ${\beta}$-conglycinin subunits had disappeared at 2 h of incubation time, whereas the subunits of glycinin were more resistant to degradation until 16 h of incubation. From the SDS-PAGE patterns, acidic subunits of 15, 30 and 45 kGy ${\gamma}$-irradiated SB disappeared after 8, 8 and 16 h of incubation, respectively, while the basic subunits of glycinin were not degraded completely until 24, 48 and 48 h of incubation, respectively. It was concluded that ${\gamma}$-irradiated soybean proteins at doses higher than 15 kGy could be effectively protected from ruminal degradation.

• 한국식품영양과학회지
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• 제14권2호
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• pp.202-213
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• 1985

The protein nutritional quality of foods has become an important factor to food processors with the advent of nutritional labeling regulations for foods. Then, as is true today, the officially approved assay for protein nutritional quality was the rat based protein efficiency ratio(PER) bioassay. The PER bioassay requires a minimum of 28 days to performe, and is therefore not applicable to routine quality assurance use by the food industry. Within the past ten years there has been a research emphasis placed on the development of rapid, inexpensive, biological and/or chemical based assays for protein nutritional quality. It was hoped that if a rapid assay could be developed and thoroughly tested, it could be used in lieu of the PER bioassay in the day-to-day quality assurance screening of food ingredients and products. The rapid assays developed in the hope of attaining this goal have been based on microorganisms, proteolytic enzymes, and amino acid profiles, as well as combinations of the above. In this review, it will be described and briefly discussed many of procedures which had contributed conceptually as well as practically to the development of in vitro methods for the evaluation of protein quality. Special emphasis will be placed on the C-PER(computed protein efficiency ratio) assay which combines data from in vitro protease digestion and amino acid composition to predict protein nutritional quality designed by Satterlee et al. (1980), and the DC-PER(discriminant computed PER) which is a method of estimating protein quality based on rat assay and in vitro digestibility obtained using solely essential amino acid data will be also introduced.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.507-513
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• 2006

Changes of in vitro true digestibility (IVTD) of Napiergrass (Pennisetum purpureum) were determined by a filter bag system, and their relationships to chemical composition, leaf to stem ratio, plant height, geographic location, climatic factors and harvest interval were studied and used to develop prediction models for the crude protein (CP), acid-detergent fiber (ADF), and neutral-detergent fiber (NDF) contents and IVTD. Partitioning the total variance of IVTD of Napiergrass showed that 80% was attributable to the effect of harvest interval. Days of growth, plant height, leaf/stem ratio, CP, ADF and NDF of Napiergrass had highly significant relationships (p<0.01) with IVTD. The highest coefficient of correlation between the ADF, NDF, and IVTD of Napiergrass and growth degree days was obtained when the base temperature was set at $0^{\circ}C$. Growth degree days could predict ADF, NDF, and IVTD of Napiergrass more accurately than plant height, and plant height is not suitable to predict IVTD.

• 한국식품과학회지
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• 제36권5호
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• pp.765-772
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• 2004

RS 함량이 가장 높은 볶은 일품 멥쌀가루를 사용하여 DSC로 호화온도를 측정하여 타락죽의 가열조건을 설정하였다. 이로부터 설정된 가열조건을 이용하여 타락죽의 differential scanning calorimetry(DSC) 특성과 X선회절도에 의한 결정성, 효소 저항전분(enzyme-resistant starch, RS) 함량과 in vitro 전분분해율(IVSD) 그리고 아미노산 조성과 in vitro 단백질 분해율(IVPD)에 대한 가열온도와 시간의 영향을 측정한 결과는 다음과 같다. 가열조건을 달리한 타락죽은 $185^{\circ}C$에서 25분 볶은 일품 멥쌀가루를 사용하여 50, 56.5, 64 그리고 $69^{\circ}C$에서 각각 30과 60분, 60과 120분, 120과 240분, 240과 300분 가열하여 제조하였고, 재래식으로 10분간 끓여서 만든 타락죽을 대조구로 하였다. DSC로 측정한 결과 50와 $56.5^{\circ}C$에서 가열한 타락죽은 $63.7-125.2^{\circ}C$의 온도범위에서 두개의 열전이를 나타내었는데, 이들은 각각 아밀로펙틴의 용융$(63.7-73.8^{\circ}C)$과 AM-lipid 복합체의 용융$(97.7-125.2^{\circ}C)$에 해당한다. 반면, 가열온도 64와$69^{\circ}C$에서는 $96.9-127.6^{\circ}C$에서 AM-lipid 복합체 용융을 위한 한 개의 열전이를 나타내었다. 또한 AM-lipid복합체 열전이를 위한 용융엔탈피는 가열조건에 따라서 대조구의 14.22J/g보다 낮은 것으로 나타나 대조구에서 AM-lipid 복합체 형성이 가장 많은 것으로 생각된다. X선회절도에 의하면 타락죽은 가열온도 50와 $56.5^{\circ}C$에서는 일부 회절각도에서 피크가 잔존하였다. 타락죽의 RS함량은 가열온도가 증가할수록 50>56.5>대조구>64>$69^{\circ}C$의 순서로 감소한 반면, IVSD는 50<56.5<대조구<64<$69.5^{\circ}C$의 순서로 증가하였다. 타락죽의 총아미노산 함량은 가열조건에 따라서 11,558-15,601mg/100g을 나타내었으며 $56.5^{\circ}C$에서 120분 가열 시 가장 높았다. Lysine과 tryptophane과 같은 필수아미노산 함량은 가열온도 50와 $56.5^{\circ}C$에서 재래식으로 끓여 제조한 타락죽보다 높았다. 한편 타락죽의 IVPD는 모두 대조구보다 증가하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권10호
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• pp.1427-1432
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• 2015

The experiment was conducted to determine nutritive values of caramba (Lolium multiflorum cv. caramba) fresh, silage and hay by in vivo and in vitro methods. There was a statistically significant difference (p<0.01) in crude protein content value between fresh caramba (12.83%) and silage (8.91%) and hay (6.35%). According to results of experiment, the crude fiber, neutral detergent fiber, acid detergent fiber (ADF), acid detergent lignin contents of the three forms of caramba varied between 30.22% to 35.06%, 57.41% to 63.70%, 35.32% to 43.29%, and 5.55% to 8.86% respectively. There were no significant differences between the three forms of caramba in digestibility of nutrients and in vivo metabolizable energy (ME) values (p>0.05). However, the highest $ME_{CN}$ (ME was estimated using crude nutrients) and $ME_{ADF}$ values were found in fresh caramba (p<0.01). As a result, it could be said that, there were no differences between the three forms of caramba in nutrient composition, digestibility and ME value, besides drying and ensiling did not affect digestibility of hay. Consequently, caramba either as fresh, silage or hay is a good alternative source of forage for ruminants.

• 한국축산식품학회지
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• 제37권5호
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• pp.682-689
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• 2017

The aim of this study was to investigate the digestibility of different Korean Hanwoo beef cuts using an in vitro digestion model, in vitro physicochemical upper gastrointestinal system (IPUGS). The four most commonly consumed cuts - tenderloin, sirloin, brisket and flank, and bottom round - were chosen for this study. Beef samples (75 g) were cooked and ingested into IPUGS, which was composed of mouth, esophagus, and stomach, thereby simulating the digestion conditions of humans. Digested samples were collected every 15 min for 4 h of simulation and their pH monitored. Samples were visualized under a scanning electron microscope (SEM) to examine changes in the smoothness of the surface after digestion. Analysis of the amino acid composition and molecular weight (MW) of peptides was performed using reverse-phase high performance liquid chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis, respectively. Following proteolysis by the gastric pepsin, beef proteins were digested into peptides. The amount of peptides with higher MW decreased over the course of digestion. SEM results revealed that the surface of the digested samples became visibly smoother. Total indispensable and dispensable amino acids were the highest for the bottom round cut prior to digestion simulation. However, the total amount of indispensable amino acids were maximum for the tenderloin cut after digestion. These results may provide guidelines for the elderly population to choose easily digestible meat cuts and products to improve their nutritional and health status.

• Asian-Australasian Journal of Animal Sciences
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• 제25권11호
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• pp.1559-1567
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• 2012

The objective of this study was to evaluate ruminal degradability and intestinal digestibility of crude protein (CP) and amino acids (AA) in hempseed cake (HC) that were moist heat treated at different temperatures. Samples of cold-pressed HC were autoclaved for 30 min at 110, 120 or $130^{\circ}C$, and a sample of untreated HC was used as the control. Ruminal degradability of CP was estimated, using the in situ Dacron bag technique; intestinal CP digestibility was estimated for the 16 h in situ residue using a three-step in vitro procedure. AA content was determined for the HC samples (heat treated and untreated) of the intact feed, the 16 h in situ residue and the residue after the three-step procedure. There was a linear increase in RUP (p = 0.001) and intestinal digestibility of RUP (p = 0.003) with increasing temperature during heat treatment. The $130^{\circ}C$ treatment increased RUP from 259 to 629 g/kg CP, while intestinal digestibility increased from 176 to 730 g/kg RUP, compared to the control. Hence, the intestinal available dietary CP increased more than eight times. Increasing temperatures during heat treatment resulted in linear decreases in ruminal degradability of total AA (p = 0.006) and individual AA (p<0.05) and an increase in intestinal digestibility that could be explained both by a linear and a quadratic model for total AA and most individual AA (p<0.05). The $130^{\circ}C$ treatment decreased ruminal degradability of total AA from 837 to 471 g/kg, while intestinal digestibility increased from 267 to 813 g/kg of rumen undegradable AA, compared with the control. There were differences between ruminal AA degradability and between intestinal AA digestibility within all individual HC treatments (p<0.001). It is concluded that moist heat treatment at $130^{\circ}C$ did not overprotect the CP of HC and could be used to shift the site of CP and AA digestion from the rumen to the small intestine. This may increase the value of HC as a protein supplement for ruminants.