• Journal of Animal Science and Technology
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• v.66 no.2
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• pp.340-352
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• 2024

This study measured the potential changes of the microbiota in the gastrointestinal tract and energy and nutrient digestibility by supplemental bacteriophages in pigs. Twelve castrated male pigs (initial mean body weight = 29.5 ± 2.3 kg) were surgically cannulated using T-cannula. The animals were housed individually in pens equipped with a feeder and a nipple waterer. The pigs were allotted to 1 of 3 experimental diets in a quadruplicated 3 × 2 Latin square design with 3 experimental diets, 2 periods, and 12 pigs resulting in 8 replicates per diet. The 3 diets were a control mainly based on corn and soybean meal with no antibiotics or bacteriophages, a diet containing 0.1% antibiotics, and a diet containing 0.2% bacteriophages. On day 5 of the experimental period, feces were collected and on days 6 and 7, ileal digesta were collected. Genomic DNA for bacteria were extracted from the ileal digesta and feces and the V4 region of the 16S rRNA gene was amplified. The ileal and fecal digestibility of energy, dry matter, organic matter, crude protein, and fiber was unaffected by dietary antibiotics or bacteriophages. At the phylum level, the supplemental antibiotic or bacteriophage tended to result in a higher proportion of Firmicutes (p = 0.059) and a lower proportion of Bacteroidetes (p = 0.099) in the ileal digesta samples compared with the control group with no difference between the antibiotic and bacteriophage groups. At the genus level, the supplemental antibiotic or bacteriophage tended to result in a higher proportion of Lactobacillus (p = 0.062) and a lower proportion of Bacteroides (p = 0.074) and Streptococcus (p = 0.088) in the ileal digesta compared with the control group with no difference between the antibiotic and bacteriophage groups. In the feces, supplemental antibiotics or bacteriophages reduced the proportion of Bifidobacterium compared with the control group (p = 0.029) with no difference between the antibiotic and bacteriophage groups. Overall, supplemental antibiotics and bacteriophages showed positive effect on the microbiota of in the ileal digesta without largely affecting energy or nutrient digestibility, with no differences between the antibiotic and bacteriophage groups in growing pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.5
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• pp.636-642
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• 2011

The effect of different rates of ethanol additive on fermentation quality of napiergrass (Pennisetum purpureum) and residual water soluble carbohydrate were studied in the experiment. The addition rate of ethanol was 0%, 1.5%, 2.5%, 3.5%, 4.5% on fresh weight of napiergrass. The laboratory silos were kept in the room, then were opened on 1, 3, 5, 7, 14, 30 days after ensiling and the changes of silage quality were analyzed, respectively. There was a fast and large reduction in pH from the 5th day of ensiling to below 4.2 except for the 4.5% treatment. After five days the pH of silage decreased slowly and the pH of the ethanol additions was lower than the control. Lactic acid content of ethanol treatments increased significantly (p<0.05) from the 5th day of ensiling, reaching the highest value on either the 7th day or 14th day. The ethanol additive inhibited the break down of silage protein and the ammonia nitrogen content of ethanol addition silage was significantly (p<0.05) lower than the control after 30 days of ensiling. Within the initial first day of ensiling the water soluble carbohydrate content declined quickly. The efficiency of water soluble carbohydrate usage was higher in silage with ethanol than in the control. The acetic acid of ethanol treatment was significantly (p<0.05) lower than control on first and 14th day, but there was no significant (p>0.05) difference among the ethanol addition silages. The volatile fatty acids content of silage increased gradually from the first day of ensiling and reached the peak on 14th day or 30th day and the content of ethanol addition treatment was significantly (p<0.05) lower than the control. The experimental results indicated that adding ethanol inhibited the use of protein and water soluble carbohydrate of aerobic bacteria and reduced the silage losses during the early stage of ensiling and thus supplied more fermentation substrate for lactic acid bacteria and improved the fermentation quality of napiergrass.

• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.233-238
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• 2006

In order to study the effect of feeding rare earth(RE) on growth of broiler chicks, feed conversion ratio, and probable harmfulness of feeding high levels of RE, two feeding trials with broiler chicks were conducted; one using a commercial broiler compound feed and the other using a self mixed feed excluding any growth stimulating feed additives. The the first trial used three hundred sixty of one day old Cobb broiler chicks for six levels of dietary supplementation of RE : 0, 100, 200, 400, 800 and 1,600 mg/kg. There were significant effect of RE stimulating broiler chick growth and improving feed conversion ratio, The dietary supplementation of RE at a level of 100 mg/kg was the best of all and increased body weight gain by 8.9% (p<0.05). Chicks fed RE at a level of 1,600 mg/kg grew as good as chicks fed feeds without RE and did not show my abnormalities. The second feeding trial was conducted in the same manner as the first trial using Ross broiler chicks and self-mixed experimental diets supplemented with RE at levels of 0, 50, 100 and 150 mg/kg. Differently from Results of the first trial, body weight gain and feed conversion ratio of were the best at the level of 50 mg/kg RE supplementation(p<0.05). In this trial all the birds fed RE showed significantly lower ratio of abdominal fat against live weight than those of the control group birds. Overall, it can be said that dietary supplementation of RE will improve broiler growth and feed conversion ratio and the proper dietary level would be $50\sim100mg/kg$. These results suggested that the proper level of RE for broiler chicks would be 50 to 100 mg/kg and its effectiveness is varied depending upon RE mixture. There appears abdominal fat of broiler chicks is decreased by feeding RE but further investigation is in need.

• Korean Journal of Agricultural Science
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• v.27 no.1
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• pp.25-32
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• 2000

This experiment was conducted to investigate the effect of feeding monensin on the growth performance and ruminal fermentation characteristics of Han-Woo cattle. Seventy two uncastrated Han-Woo male cattle(BW 267 kg) were randomly allotted to 0, 22, and 33 ppm monensin treatments, three replicates per treatment and eight heads per replicate. Animals were kept in an open barn for an 140-d feeding trial, Concentrates containing different levels of monensin and rice straw cut in 15cm length were fed ad libitum separately. The results obtained from this study were summarized as follows. 1. No significant difference was found in daily gain by monensin feeding. 2. Monensin did not affect the total feed (concentrate + roughage) intake: however, as the monensin level increased, the total feed intake tended to decrease, resulting in 5 % reduction in 33 ppm monensin treatment. 3. Although no significant difference was found among three treatments, 22 and 33 ppm monensin improved the feed efficiency(total feed/gain) by 5.2 % and 5.1 %, respectively, as compared to the 0 ppm monensin treatment. 4. Monensin did not affect the concentrations of ruminal total VFA and acetic acid consistently. Although not significant, monensin feeding of 22 and 33 ppm caused marked increase in ruminal propionic acid concentration, 13.8 % and 19.3 %, respectively. Ruminal butyric acid concentration decreased as monensin level increased. Monensin feeding, regardless of level, decreased the A/P ratio by 12.5 %. In conclusiuon, monensin feeding increased the propionic acid concentration, and decreased the butyric acid concentration and A/P ratio in the rumen. Animals fed monensin consumed less feed, causing the improvement in feed efficiency. Thus, monensin appeared to be a useful feed additive, directing the rumen fermentation in a more productive way. Feed efficiency improved similarly both in 22 and 33 ppm monensin treatments, indicating that 22 ppm might be good enough rather than the 33 ppm monensin level.

• Korean Journal of Veterinary Service
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• v.35 no.4
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• pp.343-346
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• 2012

This study was investigated the effects of feeding the combination with Lactobacillus plantarum and Bacillus subtilis on the diarrhea incidence and fecal microflora of weaned calves. A total of 12 newly weaned calves were allocated to two dietary treatments in a randomized design based on body weight. The dietary treatments included a commercial basal diet supplemented with: 1) no microbial inoculants (Control); 2) a mixture of Lactobacillus plantarum and Bacillus subtilis (LB). Calves were fed diets for a 4-week period. At the end of the experiment, the counts of fecal lactic acid bacteria and Enterobacteriaceae in LB were significantly improved compared to control (P<0.05). Over the 4-week period, fecal scores and duration of diarrhea in LB were significantly decreased compared with those in control (P<0.05). The present results suggest that LB is a potential feed additive which could be used for the balance of intestinal microflora and the prevention of diarrhea in Korean native calves.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.10
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• pp.1411-1416
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• 2004

The objective of this work was to isolate a microorganism, able to produce high lactate dehydrogenase (LDH) activity, for use as a microbial feed additive. The LDH is an important enzyme for lactate conversion in the rumen, thereby possibly overcoming lactic acidosis owing to sudden increases of cereal in the diets of ruminants. In the present study, various bacterial strains were screened from a variety of environments. Among the isolated microorganisms, strain FFy 111-1 isolated from a Korean traditional fermented vegetable food called Kimchi showed the highest enzyme activity, along with retaining strong enzyme activity even in rumen fluid in vitro. Based on morphological and biochemical characteristics as well as compositions of cellular fatty acids plus API analyses, this strain was identified as Lactobacillus sp. The optimum temperature and pH for growth were found to be 30$^{\circ}C$ and pH 6.5, respectively. A maximum cell growth of 2.2 at $A_{650}$ together with LDH activity of 2.08 U per mL was achieved after 24 h of incubation. Initial characterization of FFy 111-1 suggested that it could be a potential candidate for use as a direct-fed microbial in the ruminant animals.

• Journal of Powder Materials
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• v.25 no.3
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• pp.220-225
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• 2018

The microstructure and mechanical characteristics of SUS630 specimens fabricated using the direct energy deposition (DED) process are investigated. In DED, several process parameters such as laser scan speed, chamber gas flow, powder carrier gas flow, and powder feed rate are kept fixed; the laser power is changed as 150 W, 180 W, and 210 W. As the laser power increases, the surface becomes smooth, the thickness uniformity improves, and the size and number of pores decreases. With the increase in laser power, the hardness deviation decreases and the average hardness increases. The microstructure of the material is columnar; pores are formed preferentially along the columnar interface. The lath-martensite phase governs the overall microstructure. The volumetric fraction of the retained austenite phase is measured to increase with the increase of laser input power.

• KSBB Journal
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• v.15 no.3
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• pp.274-279
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• 2000

A Saccharomyces cerevisiae isolated from a feed additive yeast product was cultivated in a Korean paper digestion wastewater in order to investigate the possibility of using it as substrate for the yeast. The yeast couldn't grow in the wastewater. It could grow in the wastewater diluted and the optimum dilution rate was 7.5 In batch cultivation with the jar fermenter the maximum total cell count was $1.34{\times}107/mL$ was obtained by the addition of undiluted digestion wastewater. By adding $(NH_4)_2S0_4 and KH_2P0_4$together with the undiluted wastewater the maximum cell concentration could be obtained faster.

• Journal of the Korean Society of Combustion
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• v.16 no.4
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• pp.23-30
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• 2011

In the iron and steel manufacturing, sintering process precedes blast furnace to prepare feed materials by agglomerating powdered iron ore to form larger particles. There are several techniques which have devised to improve sintering production and productivity including flue gas recirculation(FGR) and additive gas enriched operation. The application of those techniques incurs variations of process configurations as well as inlet and outlet gas conditions such as temperature, composition, and flow rate which exert direct influence on reactions in the bed or the operation of the entire plant. In this study, an approach of sintering bed modeling using flowsheet process simulator was devised in consideration of FGR and the change of incoming and outgoing gas conditions. Results of modeling for both normal and FGR sintering process were compared in terms of outgoing gas temperature, concentration, and moisture distribution pattern as well as incoming gas conditions. It is expected to expand the model for various process configurations with FGR, which may provide the usefulness for design and operation of sintering plant with FGR.

• Fisheries and Aquatic Sciences
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• v.5 no.3
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• pp.172-177
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• 2002

This study was conducted to investigate the utilization of Sargassum meal in the diet on juvenile ayu (Plecoglossus altivelis) reared in seawater. White fish meal and wheat flour were used as the dietary protein and carbohydrate sources in the control diet. Wheat flour in the control diet was replaced with $5\%$ and $10\%$ Sargassum meal. Three replicate groups of fish average weighing 4.0 g were fed one of three isonitrogenous$(45\%)$ and isocaloric (14.5 MJ /kg diet) diets for 7 weeks. Survival of all groups were above $80\%$. Weight gain, feed efficiency and protein efficiency ratio were not significantly affected by dietary Sargassum meal levels (P>0.05). There were no significant differences (P>0.05) in moisture, crude protein, crude lipid, crude ash and fatty acid compositions of whole-body fish among groups. It is concluded that Sargassum meal could be used as a dietary additive or alternative low-cost dietary ingredient up to $10\%$ for juvenile ayu reared in seawater.