• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.2
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• pp.15-22
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• 1980

Alkali digestion value of rice kernels was increased with delayed planting date and decreased with temperature during ripening. Varietal difference in average digestion value between low and high groups of rice varieties was the greatest under the conditions of 1.4 percent solution of potassium hydroxide, early planting and day/night temperature of 30/22$^{\circ}C$ Segregation ratio of alkali digestion value in $F_2$ generation was varied with crosses showing 3:1 for nine crosses, 1:3 for one cross, 9:7 and 13:3 for two crosses respectively and non-segregation for one cross of 15 crosses between low and high varieties in the digestion value.

• Journal of Animal Science and Technology
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• v.66 no.2
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• pp.374-386
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• 2024

To predict the apparent total tract digestibility (ATTD) of crude protein (CP) in dogs we developed an in vitro system using an in vitro digestion method and a statistical analysis. The experimental diets used chicken meat powder as the protein source, with CP levels of 20% (22.01%, analyzed CP value as dry-based), 30% (31.35%, analyzed CP value as dry-based), and 40% (41.34%, analyzed CP value as dry-based). To simulate in vivo digestive processes a static in vitro digestion was performed in two steps; stomach and small intestine. To analyze ATTD the total fecal samples were collected in eight neutered beagle dogs during the experimental period. CP digestibility was calculated by measuring CP levels in dog food, in vitro undigested fraction, and dog feces. In result, CP digestibility at both in vivo and in vitro was increased with increasing dietary CP levels. To estimate in vivo digestibility the co-relation of in vivo ATTD and in vitro digestibility was investigated statistically and a regression equation was developed to predict the CP ATTD (% = 2.5405 × in vitro CP digestibility (%) + + 151.8). The regression equation was evaluated its feasibility by using a commercial diet. The predicted CP digestibility which was calculated by the regression equation showed high index of similarity (100.16%) with that of in vivo in dogs. With that, it would be a feasible non-animal method to predict in vivo CP digestibility by using in vitro digestion method and the proposed linear regression equation in adult dogs.

• Preventive Nutrition and Food Science
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• v.6 no.3
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• pp.180-186
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• 2001

Bone marrow cell proliferating arabinogalactan-like polysaccharide (ALR-3IIa-1-1) has been purified from rhizomes of Atractylodes lancea DC. In order to characterize the essential structure of ALR-3IIa-1-1 for expression of the activity, sequential enzymatic digestion using ego-$\alpha$-L-arabinofurasidase (AFase) and ego-$\beta$-D-(1longrightarrow3)-galactanase (GNase) was employed. After ALR-3IIa-1-1 was digested with the AFase, the GNase digestion cleaved only 10% and 23% of 3-linked and 3,6-branched galactose, respectively, from arabinose-trimmed ALR-3IIa-1-1 (AT-ALR-3IIa-1-1), and gave small amounts of intermediate size (AT-G-2) and shorter oligosaccharides (AT-G-3) fractions in addition to a large amount of the GNase resistant fraction (AT-G-1). When AT-G-1 was redigested gradually with the AFase and GNase, it released trace amounts of oligosaccharides in addition to a large amount of the resistant fraction. When the final enzyme-resistant fraction from AT-G-1 was digested simultaneously with both AFase and GNase, the resistant fraction was significantly degraded into two long fragments (3AT-3G-1 and 2). The mixture of digestion products from the first GNase digestion of AT-ALR-3IIa-1-1 showed a significantly decreased bone marrow cell proliferation activity to about 30% of the activity of ALR-3IIa-1-1, but the GNase resistant fraction (AT-7-1) still had significant activity. Although the second gradual enzymatic digestion of AT-G-1 showed a marginal decrease in activity, the resulting fragments (3AT-3G-1 and 2) by the final simultaneous enzymatic digestion lost most of the activity. Component sugar, methylation and FAB-MS analyses indicated that the digestion products (AT-G-21 AT-G-31 2AT-2G-2 and 2AT-2G-3) released from AT-ALR-3IIa-1-1 by the sequential enzymatic digestion contained galactose-containing oligosaccharides mainly comprising 6-linked galactose, that some of which were partially arabinosylated, and these oligosaccharides were attached to $\beta$-D-(1longrightarrow3)-galactan backbone in its non-reducing terminal side as side chains.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.2
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• pp.282-295
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• 2005

The processing of dietary lipids can be distinguished in several sequential steps, including their emulsification, hydrolysis and micellization, before they are absorbed by the enterocytes. Emulsification of lipids starts in the stomach and is mediated by physical forces and favoured by the partial lipolysis of the dietary lipids due to the activity of gastric lipase. The process of lipid digestion continues in the duodenum where pancreatic triacylglycerol lipase (PTL) releases 50 to 70% of dietary fatty acids. Bile salts at low concentrations stimulate PTL activity, but higher concentrations inhibit PTL activity. Pancreatic triacylglycerol lipase activity is regulated by colipase, that interacts with bile salts and PTL and can release bile salt mediated PTL inhibition. Without colipase, PTL is unable to hydrolyse fatty acids from dietary triacylglycerols, resulting in fat malabsorption with severe consequences on bioavailability of dietary lipids and fat-soluble vitamins. Furthermore, carboxyl ester lipase, a pancreatic enzyme that is bile salt-stimulated and displays wide substrate reactivities, is involved in lipid digestion. The products of lipolysis are removed from the water-oil interface by incorporation into mixed micelles that are formed spontaneously by the interaction of bile salts. Monoacylglycerols and phospholipids enhance the ability of bile salts to form mixed micelles. Formation of mixed micelles is necessary to move the non-polar lipids across the unstirred water layer adjacent to the mucosal cells, thereby facilitating absorption.

• Journal of Animal Science and Technology
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• v.49 no.1
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• pp.129-136
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• 2007

This study was performed to determine the protein profiles using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Angiotensin-I-converting enzyme(ACE) inhibitory activity (IC50) as affected by the various meat cuts, digestion times with pepsin. Hydrolysates having the protein concentration of 10 ug/mL had approximately 36∼39% ACE inhibitory activities, regardless of meat cut and digestion time. Protein concentration and ACE inhibitory activity of the diluted hydrolysate increased after 1-hr digestion. In original hydrolysates, ACE inhibitory activities of loin had higher than those of round (P<0.05). In addition, non-heated hydrolysates had higher ACE inhibitory activities than heated counterparts. When myosin B was digested by pepsin more than 1 hr, improved ACE inhibitory activities were observed as compared to the non-digested control.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.2
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• pp.230-236
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• 2018

Objective: Two ex vivo experiments were conducted to verify the effect of barley grain (Nusrat cultivar) treated with alkaline compounds (AC) including alum, ammonium, and sodium hydroxide or cation-exchanged organic extracts (OE) prepared from alfalfa hay, sugar beet pulp and Ulva Fasciata, on extent and digestion of starch. Methods: In the first study, the in vitro first order disappearance kinetic parameters of dry matter (DM), crude protein (CP) and starch were estimated using a non-linear model ($D_{(t)}=D_{(i)}{\cdot}e^{(-k_d{\cdot}time)}+I$, where: $D_{(t)}$ = potentially digestible residues at any time, $D_{(i)}$ = potentially digestible fraction at any time, $k_d$ = fractional rate constant of digestion (/h), I = indigestible fraction at any time). In the second experiment, the ruminal and post-ruminal disappearance of DM, CP, and starch were determined using in situ mobile nylon bag. Results: Barley grains treated with alum and alfalfa extract had a higher constant rate of starch digestion (0.11 and 0.09/h) than others. Barley grain treated with OE had a higher constant rate of CP digestion and that of treated with AC had a higher constant rate of starch digestion (0.08 and 0.11/h) compared with those of the other treatments. The indigestible fraction of starch treated with alum and sugar beet pulp extract was higher than that of the control group (0.24 and 0.25 vs 0.21). Barley grain treated with AC and OE had significant CP disappearance in the rumen, post-rumen and total tract, and also starch disappearance for post-rumen and total tract compared with the untreated (p<0.001). Conclusion: This study demonstrated that AC and OE might have positive effects on the starch degradation of the barley grain. In addition, treating barley grain with alum and sugar beet pulp extract could change the site and extend digestion of protein and starch.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.7
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• pp.1162-1169
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• 1999

Modern livestock production facilities face both challenges and opportunities with respect to sustainable manure management practices. Nutrient recycling is constrained by the size of modern livestock operations, the low nutrient density of liquid manures, and the spatial and temporal variability of manure nutrient concentrations. These constraints can and must be addressed or farmers will be increasingly drawn to nutrient wasting strategies such as anaerobic lagoons, wetlands, and other systems designed to treat and discharge nutrients to the environment. Intentional discharge of nutrients is difficult to justify in a sustainable agricultural production system, since replacing those nutrients through chemical fertilization requires considerable expenditure of energy. In contrast, there are several currently viable technologies which provide the homogenization and stabilization needed to successfully compete against chemical fertilizers, including composting, pelletization, and anaerobic digestion. Some of these technologies, particularly anaerobic digestion and composting, also open up increased opportunities to market the energy and nutrients in manure to non-agricultural uses. Future advances in biotechnology are likely to demonstrate additional options to transform manure into fuels, chemicals, and other non-agricultural products.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.65-66
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• 2005

Anaerobic digestion is one of the well-known methods for biological treatment handling of concentrated organic matter such as swine $wastewater.^{1)} The anaerobic digestion can reduce organic loading but also hydrolyze non-biodegradable organic $matter.^{2)}$ The feces from the scrapper-type barn are usually collected to make compost and the urine is discarded with swine-slurry wastewater by ocean-dumping or treated by biological methods. The lagoon, aerobic digestion, anaerobic digestion, SBR, $A^{2}/O$, and UCT have been applied for treating swine $wastewater.^{3)} In this study, as a result of the analysis of swine wastewater, the total and soluble chemical oxygen demand was 130g/L and 60g/L, respectively. And the volatile fatty acid as chemical oxygen demand equivalent was 45g/L, which was 75% of soluble chemical oxygen demand. Before everything else, ammonia nitrogen concentration was 6.5 g/L. From biochemical acidogenic potential test, it was concluded that the enhanced acidification process to manage swine waste should be operated in the ammonia nitrogen concentration of less than 1.2 g/L. In the result of seeding ratio experiments with artificial $wastewater^{4)}, the lag period of acidogens was taken the long time because of the inhibition by the $ammonia^{5)}$, however no difference of period by the seeding ratio was not shown. The Haldane-based biokinetics were also evaluated using a method of fourth order Runge-Kutta $approximation.^{6,7)}$ The nonlinear least squares (NLLS) method with a 95% confidence interval was also used. The ranges of maximum microbial growth rate, ${/mu_{max}}$, and half saturation coefficient, $K_{s}$, for acidogenesis of various seeding ratio with artificial wastewater were 6.1 ~ 12.6 $d^{-1}$ and 45,000 ~ 53,500 mg glucose/L, respectively. Also, the methanogenic microbial yield coefficient, Y, and microbial decay rate coefficient, $k_{d}$, and inhibition substrate concentration, $K_{si}$, for the reactors were determined to be 0.32 ~ 0.465 ${/mu}g$/mg glucose; 0.42 ~ 1.01 $d^{-1}$ and 51,500 ~ 55,600 mg glucose/L, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.6
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• pp.812-815
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• 2005

This study was conducted to see the influence of additives and fermentation periods on Mott grass silage (MGS) characteristics, its chemical composition and to compare the digestion kinetics of Mott grass (MG) and MGS in Nili buffaloes. Mott grass chopped with a locally manufactured chopper was ensiled using two additives, cane molasses and crushed corn grains each at 2, 4 and 6% of forage DM for 30 and 40 days in laboratory silos. The pH, lactic acid concentration, dry matter (DM), crude protein and fiber fractions of MGS were not affected by the type or level of additive and fermentation periods. The non-significant pH lactic acid concentration, and chemical composition of MGS indicated that the both molasses and crushed corn were utilized at similar rate for the growth of lactic acid bacteria and production of organic acids. The MG ensiled with molasses at 2% of fodder DM for 30 days was screened out for in situ digestion kinetics in Nili buffaloes. Ruminal DM and neutral detergent fiber (NDF) degradabilities of MGS were significantly (p<0.05) higher than that of MG. The DM and NDF rate of degradation, lag time and extent of degradation was nonsignificant between MGS and MG. The higher ruminal degradation of DM and NDF of MGS than MG was probably a reflection of fermentation of MG during ensilation that improved its degradability by improving the availability of easily degradable structural polysaccharides to ruminal microbial population. The results in the present study have indicated that MG ensiled with either 2% molasses or 2% crushed corn for 30 days has better nutritive value for buffalo.

• KSBB Journal
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• v.16 no.4
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• pp.389-397
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• 2001

The effect of sludge digestion on the leaching efficiency of heavy metals from sludge by bioleaching with Thiobacillus thiooxidans MET was investigated. The used sludges were a non- and anaerobically digested. The leaching efficiency of heavy metals was strongly dependent on the pH of the sludge solution rather than the sludge condition and stolid concentration. The lower the pH the more heavy metal was leached from 3.0 of pH. The sequent orders of leaching heavy metals were Zn, Cu, and Cr. Although the buffering capacity of non-digested sludge was similar to anaerobically digested sludge, the pH decrease rate of the anaerobically digested sludge solution was faster than that of the non-digested sludge solution due to the higher sulfur oxidation rate of T. thiooxidans MET in the anaerobically digested sludge. The amount of leached heavy metals from the anaerobically digested sludge showed higher than that of non-digested sludge at the same pH value. This result might be caused by the difference of the insoluble metal types, which were contained in the sludge. An increase in sludge solids concentration decreased the leaching efficiency of heavy metals in the range of solids concentration 10 g/L to 70 g/L. The optimum ratio of S° to sludge stolid was 0.1 in both the sludge. The bioleaching process of heavy metals with T. thiooxidans MET showed the disinfecting effect over 90% as well as the reduction effect in sludge weight of 20%.