• Animal Bioscience
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• v.36 no.2
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• pp.238-247
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• 2023

Objective: Recently, indigenous Korean grass Sasa quelpaertensis Nakai (SQ) has garnered much interest as a roughage source for livestock to mitigate its adverse effects on habitat diversity. Thus, the objective of the present study was to evaluate the ruminal fermentation, palatability, and nutrient digestibility of SQ for Korean native beef cattle (Hanwoo) using in vitro rumen fermentation, in situ rumen degradability, and in vivo feeding trials. Methods: Using in vitro tests with rumen fluid as the inoculum for 48 h, ruminal fermentation of SQ was evaluated and compared with that of other roughage sources commonly used in Korea (i.e., rice straw, Timothy hay, and Italian ryegrass [IRG]). Additionally, an in situ trial 96 h was performed using three cannulated Hanwoo steers. Further, an in vivo trial was performed using eight Hanwoo steers to compare the palatability of SQ with rice straw in total mixed ration (TMR) and forage-concentrate separate feeding conditions. Finally, an in vivo digestibility trial of SQ fed as TMR of two particle sizes was performed with four Hanwoo steers. Results: In vitro and in situ trials revealed that SQ was comparable or superior to rice straw in terms of the ruminal fermentation characteristics of pH, gas production, total volatile fatty acid content, and effective ruminal dry matter digestibility (DMD), although its fermentability was lower than that of Timothy hay and IRG. In the palatability test, steers showed a greater preference for SQ when given as TMR. The total tract DMD of SQ fed as TMR was 75.9%±1.37%, and it did not differ by particle size. Conclusion: The feed value of SQ as a roughage source for Hanwoo steers is comparable or superior to that of rice straw, particularly when provided as TMR.

• Journal of Biosystems Engineering
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• v.43 no.2
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• pp.119-127
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• 2018

Purpose: Fermented feedstuffs have been found to improve productivity, reduce manure odor, and increase immunity. However, because there is not a commercialized pelletizing system for fermented total mixed ration (TMR) for pig feeding in Korea, a pelletizing system using TMR fermented feed was developed. Methods: The particle size, density, and volumetric density of the TMR feeds used in the test were measured. The pellet durability index (PDI, %) value of the pelletized TMR feed based on its moisture content, and the amount of pellet production based on the rotation speed of the compression roller were measured. Results: The test materials, TMR1 and TMR2, were approximately compressed to 387 kg/m3 with 18.2% (w.b.) and 544 kg/m3 with 22.2% (w.b.), respectively. Throughout this pellet molding test, the moisture content from 15 to 20% (w.b.) of mixture feedstuffs, including fermented forage, could be used for pellet molding. Based on the results, a small-scale pellet molding system of fermented TMR was designed and manufactured for pig farms. As rotation speed increased, the throughput increased, whereas the moisture content decreased by approximately 2% (w.b.) because of pellet molding. The best yield of pellets with 94.2% PDI was of 536 kg/h at 135 rpm rotation speed. Conclusions: Although the throughput of the prototype increased as the rotation speed increased, it was difficult to operate because of the greater noise and the lower PDI (%) at the higher rotation speed of the pellet molding rotor. It was found that the best production of pellets using the prototype was 536 kg/h having a PDI of 94.2% or more at a rotation speed of 135 rpm.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.677-680
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• 2008

The surface of particles was energetically modified by inter-grinding OPC and BFS in vibration mill for improvement of the early strength and low-heat evolution of concretes. BFS was pre-grinding in ball-mill to 2535(BS2) and 3245 $cm^2/g$(BS3), in blaine surface area. The inter-grinding time in vibration mill was changed from 10 minutes to 30 minutes. And Mixing ration of BFS to OPC was changed in 60, 70, 80%. After inter-grinding, the change of specific surface area, particle size distribution, hydration heat of cement and compressive strength of mortar were measured. As the result of comparison test with LHC, it was found that the mixture and inter-grinding time satisfying the value of over 100% of compressive strength for 7 days and under 170J/g of heat of hydration for 72 hours. and it was confirmed that the possibility of low heat slag cement utilizing blast furnace slag(BS2, BS3) with the low fineness in high volumes.

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1433-1442
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• 2021

In this study, Saccharomyces cerevisiae culture fluid (SCCF) has been added to a diet of lactating dairy cows to attempt to improve the ruminal fermentation and potentially increase the dry matter intake (DMI) and milk yield. This study was conducted to investigate the effects of SCCF on the milk yield and blood biochemistry in lactating cows during the summer. Twenty-four Holstein dairy cows were randomly assigned to one of four treatments: (1) total mixed ration (TMR-1) (Control); (2) TMR-1 supplemented with SCCF (T1); (3) TMR-2 (containing alfalfa hay) (T2); and (4) TMR-2 supplemented with SCCF (T3). SCCF (5 ml/head, 2.0×10⁷ CFU/mL) was mixed with TMRs daily before feeding to dairy cows. The mean daily temperature-humidity index (THI) during this trial was 76.92 ± 0.51 on average and ranged from 73.04 to 81.19. For particle size distribution, TMR-2 had a lower >19 mm fraction and a higher 8-9 mm fraction than TMR-1 (p < 0.05). The type of TMR did not influence the DMI, body weight (BW), milk yield and composition, or blood metabolites. The milk yield and composition were not affected by the SCCF supplementation, but somatic cell counts were reduced by feeding SCCF (p < 0.05). Feeding SCCF significantly increased the DMI but did not affect the milk yield of dairy cows. The NEFA concentration was slightly decreased compared to that in the control and T2 groups without SCCF. Feeding a yeast culture of S. cerevisiae may improve the feed intake, milk quality and energy balance of dairy cows under heat stress.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.3
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• pp.196-201
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• 2011

Emission from meat cooking may contribute to the concentration of the Particulate Matters(PM) in the city. This study is to investigate the particle size and the emission characteristics of particulate matters from pork and beef cooking. The chamber was installed for sampling of PM generated from pork belly and beef sirloin cooking including seasoned ones. Cascade Impactor and Portable Aerosol Monitor (PAM) were used to analyse the particle size distribution. At the result of the Cascade Impactor sampling, particulate matters from the pork cooking was higher than that of beef. The gravimetric concentration of PM according to the size was highest at the range of $1.95{\sim}3.2{\mu}m$ and the gravimetric concentration of PM from the non-seasoned meat was higher than that of the seasoned one. The emission factors from pork, pork seasoned, beef and beef seasoned were 1.36 g/kg, 1.03 g/kg, 1.23 g/kg, 0.92 g/kg respectively. To see the result of PAM sampling, the ranges of $1.6{\sim}2.5{\mu}m$ and $2.5{\sim}3.5{\mu}m$ were reveled as highest. The ration of $PM_{2.5}/PM_{10}$ from pork and beef was 0.56~0.58. The emission factors from pork, pork seasoned, beef and beef seasoned measured by PAM were revealed as 3.37 g/kg, 2.76 g/kg, 2.93 g/kg, 2.77 g/kg respectively.

• Composites Research
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• v.31 no.5
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• pp.209-214
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• 2018

This paper explain about the development of environmental friendly, low cost and stable supply material i.e., rice husk and shell were used as micro incorporating bio waste filler. Those were processed by ball mill and analyzed through micro observation by FE-SEM, EDS and particle size distribution. The obtained filler was mixed with epoxy resin for the manufacturing of CFRP composite and study tensile properties. In EDS analysis main contents of rice husk and rice husk ash are C, O and Si. When rice husk was burned C and Si ration were increased. Shell powder has C, O and Ca. It caused $CaCO_3$ from shell. Surface weighted mean of rice husk powder is $6.19{\mu}m$ and volume weighted mean is $14.77{\mu}m$. And it has rod type particles which caused hair and husk structure parts. Surface weighted mean of rice husk ash powder is $1.55{\mu}m$ and volume weighted means is $8.20{\mu}m$. Surface weighted mean of shell powder is $2.53{\mu}m$ and volume weighted mean is $5.79{\mu}m$. The tensile decreased with increasing the content of micro filler in CFRP composites. In case of rice husk, the significant decrement of tensile strength was observed. and in case of shell powder, there is no effect of changes take place in tensile strength.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.11
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• pp.626-633
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• 2017

The present study investigated the effect of a water-washing process, which is part of the acid hydrometallurgical process for recovery of high purity of zinc, on the removal of alkali metals and chlorides (Na, K, Ca, Cl) from Electric arc furnace dust (EAFD). Two EAFD samples with different properties were characterized by particle size, XRD and element analysis, and their washing efficiencies (%) on alkali metals and chlorides were compared according to pH, washing time, liquid to solid (L/S) ratio and number of washings. The results show that the alkali metals and chlorides could be effectively removed by the washing (at L/S ration of 3 for more than 30 min., pH 10~11) while minimizing loss of zinc (<0.1%), in which the washing efficiency was Na-78%, K-76%, Cl >99%, respectively. Na and K could be removed up to 97% and 89% respectively by 3 times of repeated washings. With increased sample volume (10 times) of the mixed (1:1, w/w) sample with two types of EAFD, it was confirmed that the pH(10~11) can be used as the main process control parameter for the washing of the alkali metals regardless of EAFD properties.