• Korean Chemical Engineering Research
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• v.55 no.5
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• pp.660-667
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• 2017

Equilibrium data of the mixture is essential in the design and operation of separation equipment such as distillation or extraction in chemical processes. These equilibrium data can be obtained through experiments or by calculations using the known binary parameters and the thermodynamic models. Generally, to obtain these parameters, phase equilibrium experimental data such as gas-liquid and liquid-liquid are used. In this study, the excess enthalpy of the mixture was measured using the flow type microcalorimeter which is a simpler method than phase equilibria experiments, and the parameters of various theories were obtained by using this data. In order to investigate the relationship between carbon chain length, enthalpy and binary parameters in the alkane system, excess enthalpies for the n-hexane + alkane (n-pentane, n-heptane, n-octane and n-dodecane) were measured at 298.15 K and the banary interaction parameters of Wilson, NRTL, and UNIQUAC were obtained from the experimental data. In addition, we wanted to obtain basic information on the interaction and association phenomena of the system including electrolyte applicable to various fields by using the excess enthalpy experimental data and the existing theory. First, we investigated the excess enthalpy for the NaOH / Water / Ethanol system as a basic experiment and examined the applicability using the electrolyte-NRTL (eNRTL) theory.

• Journal of Aquaculture
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• v.1 no.1
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• pp.1-11
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• 1988

There are many problems to be solved for the establishment of more feasible and simplified method of seed production of marine fishes. One of the most important tasks in seed production is to clarify the feeding ecology of larvae and juveniles under. rearing conditions. In the present study, two groups of postlarvae-juveniles of the flounder, Paralichthys olivaceus were used. One ranging 11.38 to 17.08 mm in mean total length was fed with Artemia nauplii at two different water temperatures (19 to $21^{\circ}C$ and 24 to $25^{\circ}C$) and the other ranging 4.39 to 10.64 cm in mean total length was fed with prepared diet. Time required from the start of feeding to satiation was 45 to 55 minutes at 24 to $25^{\circ}C$ and nearly one hour at 19 to $21^{\circ}C$. Mean numbers of Artemia nauplii in digestive tract were 236 to 375 individuals per fish at 24 to $25^{\circ}C$. The amount of food remained in the intestine was $24.8\%$ of the total food in the digestive tract. In juveniles of 4.39 to 10.64 cm in mean total length, amount of prepared diet consumed at satiation was 0.04 to 0.46 g per fish. Digestive tract index in juveniles was rapidly decreased for 24 hours after satiation and kept nearly constant after 48 hours, showing that the time to completely digest the prepared diet in juveniles was estimated to be about 48 hours.

• Journal of Embryo Transfer
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• v.21 no.1
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• pp.45-51
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• 2006

This study was carried out to investigate effect of claw trimming on milk yield and its composition in Holstein at different lactation stages. 1 . There was no difference in daily milk yield between control and claw trimming in early, mid and late lactating Holsteins. 2. Somatic cell count (SCC) was lower in early lactation and it was higher in late lactation when claws were trimmed in Holstein. However, claw trimming did not affect SCC during mid lactation in Holstein. 3. Milk fat, protein and total solids were decreased during late lactation in Holstein after claw trimming. However, milk composition was not affected by claw trimming in early and mid lactating Holsteins.

• Journal of Animal Science and Technology
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• v.47 no.3
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• pp.397-408
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• 2005

This study, consisting of three experiments, was conducted to determine the effects of feeding feather meal (FM), feather meal digest (FMD), L-cystine and methionine hydroxyl analogue (MHA) on taurine content of milk and milk production of Holstein dairy cows. In experiment 1, FM or FMD was supplemented at 0, 1, 3 and 5% of dry matter intake (DMI), respectively. Taurine concentration of 3% FM and 5% FMD treatment were increased by 14% and 220/0, respectively. The 5% FM treatment had a negative effect on milk yield and FM and FMD treatments had no significant or consistent effects on milk fat, protein, lactose, milk urea nitrogen (MUN) and somatic cell count (SCC). In experiment 2, Lcystine or MHA was supplemented at 0, 1, 3, and 5g or ml/d along with 5% FMD, respectively. Milk yield decreased at 3 and 5g or ml Lcystine or MHA supplementation along with 5% FMD. Fat and lactose in milk were not significantly affected by treatments. However, milk protein level increased significantly in the 5 ml HMA with 5% FMD treatment. SCC decreased significantly in 1ml MHA with 5% FMD supplemented treatment but increased in 5g Lcystine with 5% FMD and 5 ml MHA with 5% FMD treatments. Increase of milk taurine concentration of L'cystine with 5% FMD treatments was not significant but those of MHA with 5% FMD treatments were significantly higher than the control. The highest increase of milk taurine concentration was 65% shown in 1 ml MHA with 5% FMD treatment. In experiment 3, 5% FM, 5% FM+3% molasses or 5% FM+3% molasses+l ml MHA was supplemented to the based TMR diet. The molasses treatments (5% FM+3% molasses and 5% FM+3% molasses+l ml MHA) showed significantly higher milk taurine content than the 5% FM treatment. The molasses treatments significantly reduced MUN but increased SCC. It was concluded that FMD is more effective than FM in enriching taurine in milk. Maximum taurine enrichment (65%) in the milk was obtained by supplementation of 5% FMD/DM1+1 ml MHA/d/cow. Molasses supplementation to 5% FM diet increased milk taurine content. However, MHA supplementation in dairy cows increased ruminal escape, gastrointestinal absorption and response of serum methionine.

• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.383-391
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• 2000

Milk urea nitrogen (MUN) determination is being used an indicator of the protein-energy balance in dairy herds. A faulty balance can be corrected to optimize milk production and animal health. This parameter is regarded as a potential tool to evaluate suboptimal feeding practices and reproductive disorders. Therefore, the purpose of this study was to investigate the response of milk composition by regular feeding analysis and to compared the relationship between MUN and milk protein(MP) and fertility at the insemination period in Holstein dairy cows. Total of 355 artificial insemination (AI) for 150 Holstein cows in the herd were used to examine the relationship between MUN and MP content and conception rate. The AI occured for the cows 50 to 150 day in milk, and MUN and MP concentration were determined using automated infrared procedures. The mean${\pm}$standard deviation of MUN and MP concentration in the herd were $15.6{\pm}2.1mg/dl$ and $3.23{\pm}0.38%$, respectively. MUN contents of bulk milk were increase by elevated crude protein intake. The conception rate was lower in the cows in which the level of MUN was lower than > 8.0mg/dl (10.0%) or > higher than 25mg/dl (15.4%) relative to the cows in MUN content of 12.0~17.9 mg/dl (36.7%) at the time of insemination. Also, lower MP than 3.0% or higher MP than 3.25% were associated with a lower conception rates. Consequently, MUN and MP analyses may be used serve as a monitoring tool of protein and energy nutritional balance to improve reproduction efficiency in Holstein dairy cows.

• Food Science of Animal Resources
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• v.22 no.2
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• pp.183-191
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• 2002

The Mongolian milk processing technology has a specific characteristic as a result of the living habits of Central Asian nomads. There are many kinds of milk products in Mongolia due to their processing activity used milk from various dairy animal species. Mongolia has over 30 kinds of dairy products and fermented milk products which are occupied more than 36% of the Mongolian dairy products. Herdsmen who engaged extensive livestock production have specific methods to conserve and prepare the starter culture of fermented milk products in nomadic condition. Specifically, Mongolian lactic starter cultures were prepared from keeping milk products and specific wild plants. Nowadays, over 5 kinds of wild plants such as Rheum undulatum L. Rheum ribes L, Rumex acetosa L. Artemisa sibersena L, Artemisa vulgare are used for lactic starter preparing. Traditional processing methods of the Mongolian fermented milk products are based on the scientific basis and there are easy to learn and operate.

• Journal of Dairy Science and Biotechnology
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• v.21 no.2
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• pp.81-87
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• 2003

This study was conducted to correlate the quality depending upon sensory evaluation of ESL(extended shelf life) and non-ESL milk during the shelf life. The most important quality assurance is sensory evaluation for dairy products. ESL and non-ESL milk were stored at $5^{\circ}C$ and $10^{\circ}C$ for 14 days. In order to compare physicochemical and sensory properties, pH, TA(titratable acidity), protein, fat, lactose, FFA(free fatty acid), and other organoleptic characteristics were measured. The results showed that physicochemical properties were not significantly changed during storage. On the other hand, the freshness was affected by storage conditions. The most freshness depending upon sensory evaluation was monitored at 5 days storage. Descriptive and acceptability analysis showed that more acceptable milk was ESL milk than non-ESL milk because of off-flavor and after taste of non-ESL milk. According to these results, it was shown that the freshness of milk products depends on sensory. And ESL milk was fresher than non-ESL milk after storage.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.512-517
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• 2010

This study was conducted to the evaluate nutritional value of corn taffy residue (CTR), a by-product from Korean traditional taffy, and to investigate the dietary effect of CTR on the yield and composition of milk from dairy cows. Relatively high concentrations of residual enzymes and sugars were found in CTR. Protein and fat concentrations were high, comparable to those of corn gluten meal. Inclusion of 1, 3, and 6% CTR in total mixed rations yielded more milk (p<0.05) than in the control group, and increased milk fat (p<0.05) in high-producing cows (approximately 30 kg). In low-producing cows, (approximately 20 kg), milk yield was increased by 1 and 6% CTR, and milk protein was enhanced by 3% CTR (p<0.05). Based on these results, utilization of CTR is recommended for production of high quality and economical animal products.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.135-140
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• 2011

This study was conducted to determine the effect of grape by-product on milk yield, milk composition and blood metabolites of lactating cows. A total of 8 Holstein dairy cows (average age = 89.9 months, average lactation day = 164.4, Reproduction number = 2.8) were randomly allocated into control (no additives, CON) or grape by-product treatment (add 1 kg of grape by-product per day, GBP) for 3 weeks. The concentrations of fat, protein, lactose and total solid in milk were not affected by grape by-product supplementation. However, milk yield (23.13 vs. 21.16 kg/d) was higher (p<0.05) in GBP than in CON, while SCC was lower (p<0.05). The concentrations of glucose, alanine aminotransferase, total protein and BUN in blood did not differ between treatments. But blood aspartate aminotransferase and total cholesterol concentrations (123.75 vs. 95.34 IU/L, 200.82 vs. 180.63 mg/dl) were higher (p<0.05) in cows fed GBP than CON. As the result, grape by-product, which has a various potential benefits, could be used as a functional diet supplement for lactating dairy cows.

• Journal of Life Science
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• v.31 no.5
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• pp.520-526
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• 2021

Microbial protein is one of the sources of protein in the rumen and can also be the source of glutamate production. Glutamic acid is used as fuel in the metabolic reaction in the body and the synthesis of all proteins for muscle and other cell components, and it is essential for proper immune function. Moreover, it is used as a surfactant, buffer, chelating agent, flavor enhancer, and culture medium, as well as in agriculture for such things as growth supplements. Glutamic acid is a substrate in the bioproduction of gamma-aminobutyric acid (GABA). This review provides insights into the role of glutamic acid and glutamic acid-producing microorganisms that contain the glutamate decarboxylase gene. These glutamic acid-producing microorganisms could be used in producing GABA, which has been known to regulate body temperature, increase DM intake and milk production, and improve milk composition. Most of these glutamic acid and GABA-producing microorganisms are lactic acid-producing bacteria (LAB), such as the Lactococcus, Lactobacillus, Enterococcus, and Streptococcus species. Through GABA synthesis, succinate can be produced. With the help of succinate dehydrogenase, propionate, and other metabolites can be produced from succinate. Furthermore, clostridia, such as Clostridium tetanomorphum and anaerobic micrococci, ferment glutamate and form acetate and butyrate during fermentation. Propionate and other metabolites can provide energy through conversion to blood glucose in the liver that is needed for the mammary system to produce lactose and live weight gain. Hence, health status and growth rates in ruminants can be improved through the use of these glutamic acid and/or GABA-producing microorganisms.