• Journal of Life Science
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• v.6 no.2
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• pp.135-141
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• 1996

Possible yeast strains that could be used as feed for aquaculture were studied. It was shown that the maximum specific growth rate and the biomass yield of Kluyveromyces fragilis yeast and Candida utilis yeast under optimum pH and temperature were much higher than those of Saccharomyces cervisiae yeast which had been as established yeast diet for rotifer culture. Hence, this work was focussed on the growth characteristics of the two yeasts through flask dultures for mass production. With 5% inoculum dosage, the best values of $\mu$$_{max}$ and OD$_{max}$ were obtained with on 2.5% fructose medium and 2% YE medium for K. fragilis and C. utilis, respectively, where the values of $\mu$$_{max}$ and OD$_{max}$ were found to be 0.73 hr$^{-1}$ and 3.00 for K. fragilis and 0.59 hr$^{-1}$ and 2.80 for C. utilis. It was also found that the lag phase of the growth incresed with increasing initial zinc and NaCl concentrations and decreased with increasing inoculum dosage. Both yeasts could survive relatively well at 3.5% NaCl concentration, and only C. utilis yeast could utilize zinc.

• KSBB Journal
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• v.17 no.6
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• pp.555-559
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• 2002

Three different strains of Aureobasidium pullulans were grown in batch cultures to compare their abilities of enzyme production. It was found that specific enzyme activity was the highest with strain ATCC 9348 and the enzyme production was closely coupled to growth. Studies on morphology during the growth of A. pullulans revealed that mycelia cells were dominant at the initial stages of growth. However, yeast-like cells and chlamydospores were dominant in the latter stages of batch culture. The pattern of morphological changes during the growth period was not affected by pH. However, it appears that the ratio of intra- to extracellular enzyme activity tended to increase with fermentation time irrespective of the pH employed, suggesting that the secretion efficiency of intracellular enzyme to broth likely depends on cell morphology Using molasses as a cheap source of sucrose, enzymatic production of fructo-oligosaccharides as a feed additive with A. pullulans cells could be achieved successfully at 55$\^{C}$ and pH 5.5.

• Food Science of Animal Resources
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• v.32 no.1
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• pp.40-44
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• 2012

To develop a new starter culture for Mozzarella cheese, the immunomodulatory action of Streptococcus macedonicus LC743 in male C57BL/6 mice was studied. Mice were fed for 7 wk with feed containing 1% Mozzarella cheese made with three kinds of starter cultures from S. macedonicus LC743 (G3), FD-DVS TCC-3 (G2) and S. macedonicus LC743 : FD-DVS TCC-3(1:1) (G4) and control (feed only, G1), respectively. No significant differences in body weight gain were observed among the various groups of mice. The spleen index and thymus index were observed and no significant differences were found among the groups. The production of TNF-${\alpha}$ of S. macedonicus LC743 group significantly increased compared to the control group. The production of IL-$1{\beta}$ was significantly enhanced by the feeding of S. macedonicus LC743 group compared to the control group. In regards to the white blood cell counts, the neutrophil percentages were significantly higher in the G1 group compared to other groups. The lymphocyte percentages were significantly higher in G2, G3 and G4 groups in comparison to the control group. The results of this study may suggest that the supplementation of S. macedonicus LC743 can increase the cytokine production activity by the activated macrophages in mice. Based on the result of this study, it could be concluded that S. macedonicus LC743 could stimulate the immune functions of mice.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.512-516
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• 2008

To search for anit-H5N1 influenza virus agent, the anti-viral activity of methanol and aqueous extracts from thirty medicinal plants were examined in this study. The plant material (30 g) was extracted with methanol (300 mL) for 24 hr at room temperature. Methanol extracts were filtered and evaporated, then freeze-dried. Aqueous extracts were prepared with dried plant material (30 g) and hot distilled water (300 mL). After 3 hr, the aqueous extracts were filtered and evaporated, then lyophilized. Extracts prepared from different plants were tested the antiviral activity against influenza viruses [A/vietnam/1194/04 (H5N1)-NIBRG-14] using the hemagglutination (HA) assay. Among the test plants, Asarum sieboldii was found to be a potent inhibitor of H5N1 influenza virus in MDCK cell culture. Virus titers were 7 log, whereas with methanol extract of Asarum sieboldii for 48 hr titers were 3 log, indicating that methanol extract of Asarum sieboldii inhibited the H5N1 influenza viruses from the infected cells.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.617-623
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• 2021

The study was conducted to investigate the dietary supplementation of citrus by-product (CBP) and CBP fermented with Bacillus subtilis (BS) or B. pumilus (BP) on growth performance, feed utilization, innate immune responses and disease resistance of Korean rockfish Sebastes schlegelii. Triplicate groups of juvenile fish (initial weight of 22.9 g) were fed one of five experimental diets which were formulated to replace a synthetic vitamin C (L-ascorbyl-2-polyphosphate, LAPP) with CBP or fermented CBP. A basal diet without LAPP and CBP was used as the control diet (Con). At the end of the 13 weeks feeding trial, growth performance, feed utilization and survival of fish fed the Con were significantly lower than those of fish fed the LAPP, CBP and fermented CBP diets. Fish fed the Con were significantly lower in lysozyme activity than fish fed LAPP, CBP and fermented CBP diets. In a challenge test against Edwardsiella tarda, cumulative mortality of fish fed LAPP, CBP and fermented CBP diets was significantly lower (20-30%) than that of the Con (60%). The findings in this study indicate that the CBP and/or fermented CBP can be a promising vitamin C source for LAPP replacement in diet for Korean rockfish.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.10
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• pp.1511-1520
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• 2019

Objective: The present study was conducted to select a plant oil without inhibitory effects on rumen fermentation and microbes, and to determine the optimal supplementation level of the selected oil in a series of in vitro studies for dietary application. Then, the selected oil was evaluated in a feeding study using Thai crossbred beef cattle by monitoring growth, carcass, blood and rumen characteristics. Methods: Rumen fluid was incubated with substrates containing one of three different types of plant oil (coconut oil, palm oil, and soybean oil) widely available in Thailand. The effects of each oil on rumen fermentation and microbes were monitored and the oil without a negative influence on rumen parameters was selected. Then, the dose-response of rumen parameters to various levels of the selected palm oil was monitored to determine a suitable supplementation level. Finally, an 8-month feeding experiment with the diet supplemented with palm oil was carried out using 12 Thai crossbred beef cattle to monitor growth, carcass, rumen and blood profiles. Results: Batch culture studies revealed that coconut and soybean oils inhibited the most potent rumen cellulolytic bacterium Fibrobacter succinogenes, while palm oil had no such negative effect on this and on rumen fermentation products at 5% or higher supplementation level. Cattle fed the diet supplemented with 2.5% palm oil showed improved feed conversion ratio (FCR) without any adverse effects on rumen fermentation. Palm oil-supplemented diet increased blood cholesterol levels, suggesting a higher energy status of the experimental cattle. Conclusion: Palm oil had no negative effects on rumen fermentation and microbes when supplemented at levels up to 5% in vitro. Thai crossbred cattle fed the palm oil-supplemented diet showed improved FCR without apparent changes of rumen and carcass characteristics, but with elevated blood cholesterol levels. Therefore, palm oil can be used as a beneficial energy source.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.655-663
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• 2018

The insect gut microbiome is known to have important roles in host growth, development, digestion, and resistance against pathogens. In addition, the genetic diversity of the insect gut microbiota has recently been recognized as potential genetic resources for industrial bioprocessing. However, there is limited information regarding the insect gut microbiota to better help us understand their potential benefits for enhanced pig production. With the development of next-generation sequencing methods, whole genome sequence analysis has become possible beyond traditional culture-independent methods. This improvement makes it possible to identify and characterize bacteria that are not cultured and located in various environments including the gastrointestinal tract. Insect intestinal microorganisms are known to have an important role in host growth, digestion, and immunity. These gut microbiota have recently been recognized as potential genetic resources for livestock farming which is using the functions of living organisms to integrate them into animal science. The purpose of this literature review is to emphasize the necessity of research on insect gut microbiota and their applicability to pig production or bioindustry. In conclusion, bacterial metabolism of feed in the gut is often significant for the nutrition intake of animals, and the insect gut microbiome has potential to be used as feed additives for enhanced pig performance. The exploration of the structure and function of the insect gut microbiota needs further investigation for their potential use in the swine industry particularly for the improvement of growth performance and overall health status of pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.82-89
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• 2009

Two in vitro experiments were conducted to examine the effects of propionate precursors in the dicarboxylic acid pathway on ruminal fermentatation characteristics, $CH_4$ production and degradation of feed by rumen microbes. Fumarate or malate as sodium salts (Exp. 1) or acid type (Exp. 2) were added to the culture solution (150 ml, 50% strained rumen fluid and 50% artificial saliva) to achieve final concentrations of 0, 8, 16 and 24 mM, and incubated anaerobically for 0, 1, 3, 6, 9 and 12 h at $39^{\circ}C$. For both experiments, two grams of feed consisting of 70% concentrate and 30% ground alfalfa (DM basis) were prepared in a nylon bag, and were placed in a bottle containing the culture solution. Addition of fumarate or malate in both sodium salt and acid form increased (p<0.0001) pH of culture solution at 3, 6, 9 and 12 h incubations. The pH (p<0.0001) and total volatile fatty acids (VFA, p<0.05) were enhanced by these precursors as sodium salt at 3, 6 and 9 h incubations, and pH (p<0.001) and total VFA (p<0.01) from fumarate or malate in acid form were enhanced at a late stage of fermentation (9 h and 12 h) as the addition level increased. pH was higher (p<0.001) for fumarate than for malate as sodium salt at 3 h and 6 h incubations. Propionate ($C_3$) proportion was increased (p<0.0001) but those of $C_2$ (p<0.05) and $C_4$ (p<0.01 - p<0.001) were reduced by the addition of sodium salt precursors from 3 h to 12 incubation times while both precursors in acid form enhanced (p<0.011 - p<0.0001) proportion of $C_3$ from 6h but reduced (p<0.018 - p<0.0005) $C_4$ proportion at incubation times of 1, 3, 9 and 12 h. Proportion of $C_3$ was increased (p<0.05 - p<0.0001) at all incubation times by both precursors as sodium salt while that of $C_3$ was increased (p<0.001) from 6h but $C_4$ proportion was decreased by both precursors in acid form as the addition level increased. Proportion of $C_3$ was higher (p<0.01 - p<0.001) for fumarate than malate as sodium salt from 6 h incubation but was higher for malate than fumarate in acid form at 9 h (p<0.05) and 12 h (p<0.01) incubation times. Increased levels (16 and 24 mM) of fumarate or malate as sodium salt (p<0.017) and both precursors in acid form (p<0.028) increased the total gas production, but no differences were found between precursors in both chemical types. Propionate precursors in both chemical types clearly reduced (p<0.0001 - p<0.0002) $CH_4$ production, and the reduction (p<0.001 - p<0.0001) was dose dependent as the addition level of precursors increased. The $CH_4$ generated was smaller (p<0.01 - p<0.0001) for fumarate than for malate in both chemical types. Addition of fumarate or malate as sodium type reduced (p<0.004) dry matter degradation while both precursors in both chemical types slightly increased neutral detergent fiber degradability of feed in the nylon bag.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.4
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• pp.323-330
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• 2008

This study was carried out to evaluate the effect of application of cattle manure and chemical fertilizer on dry matter productivity and nutritive values of rye and hairy vetch according to two different sowing methods such as single or mixed-sowed cultivation. Dry matter and TDN yields for rye single culture, and rye and hairy vetch mixed culture were 7.2 and 4.0 ton/ha, and 8.0 and 4.4 ton/ha, respectively. They were significantly (p<0.05) higher than that (4.5 and 2.7 ton/ha) of hairy vetch single culture. Moreover, plots produced by mixed-sowing cultivation had a higher crude protein (CP) as 7.7% than that of only rye plot, and higher TDN and RFV as 55.8 and 79.4%, respectively. Within rye alone plots, completely cattle slurry application produced significantly higher annual DM and TDN yields (7.4 and 4.1 ton/ha) than those of P+K fertilization (7.2 and 3.9 ton/ha) as a chemical fertilizer and non-fertilizer (5.5 and 3.1 ton/ha). Cattle slurry application plot revealed 75.52 and 78.97% of N+P+K fertilization plot for annual DM and TDN, respectively. Within mixed-sowing cultivation with rye and hairy vetch, completely cattle slurry application produced 7.6 ton/ha DM and 4.5 ton/ha TDN, showing 79.50 and 86.77% of N+P+K fertilization plot, respectively. Furthermore, the CP content for cattle slurry plots was 8.5%, which was significantly (p<0.05) higher than those of other plots, and it was also highest in TDN (58.3%) and RFV (86). Overall, rye mixed-sowing with hairy vetch rather than rye alone sowing reduced DM yields, but leaded to enhancement of feed value and nutritive yields. And also, it would be expected that cattle slurry application in comparison with chemical fertilizers might result in reutilization of resources, improved forage quality and, extended harvest period by preventing feed value from rapidly deteriorating.

• Journal of Aquaculture
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• v.3 no.2
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• pp.127-133
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• 1990

Growth Comparisons of two age groups of coho salmon, Oncorhynchus kisutch, underyearling and age one, were made at Chungmu Experimental Fish Culture Station from December 17, 1988 to April 26, 1989. During the first 66 days of experimental period, the fish of underyearling group grew from 167.0 g to 633.1 g in average weight and the feed coefficient (FC) and daily growth rate (DGR) were 1.1 and $2.0\%$, respectively. In the same period, the fish of age one group grew from 396.0 g to 854.6 g in average weight and the FC and DGR were 1.1 and $2.0\%$, respectively. During the second 63 days, the fish of underyearling and age one group grew up to 1171.9 g and 1239.7 g respectively. FCs of these two groups were 1.5 and 2.6, respectively and DGRs were $1.0\%$ and $0.7\%$, respectively. Underyearling fish consumed more feed and performed better FC and DGR than age one fish. FC and DGR sharply decreased as the fish weight increased. Therefore under-yearling fish of this species seems better as seeds for seawater cage culture. For this purpose it is necessary to increase smolting rate in the underyearling group fish within a single season.