• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.992-1000
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• 2005

Campylobacter is one of the emerging foodborne pathogens, and its worldwide incidence rate is extremely high. This study was undertaken to isolate and identify Campylobacter strains from chicken carcasses in the local markets, and analyze their characteristics regarding oxygen tolerance. They were isolated after aerobic enrichment and identified by biochemical, physiological, and morphological characteristics, PCR, and 16S rDNA sequencing. Their oxygen tolerances were analyzed in terms of the cell surface hydrophobicity, cell fatty acid composition, and oxidoreductase. Five strains of C. jejuni were isolated and identified from 61 isolates from 50 chickens. Among them, C. jejuni IC21 grew well in Brucella broth and commercial milk under aerobic condition. However, in the aerobic exposure, the cell surface hydrophobicity of C. jejuni IC21 was almost the same as the other isolates, even though its morphology changed from the spiral-bacilli form into the coccoid form. Fatty acid analyses showed that all Campylobacter strains had a high composition of $C_{19:1}$, cyclopropane fatty acid, and that the amount of the other fatty acids were very similar between them. Interestingly, however, only oxidoreductase activities of C. jejuni IC21 increased highly under aerobic exposure even though its activities were almost the same as the other C. jejuni strains just after microaerobic culture. It had 11.8 times higher catalase activity, 4.4 times higher for SOD, and 2.0 times higher for NADH oxidase activities. Therefore, in the case of the aero-adaptive C. jejuni IC21, expression of oxidoreductase significantly increased under oxidative stressed condition, which might allow it to survive for a longer time and grow on food under aerobic exposure. Such new strain might be one of the explanations for the increase of campylobacteriosis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1626-1633
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• 2004

In recent, the roles of oleic acid, most abundant fatty acid in myelin, were investigated in relation to the brain functions. This study examined the effects of diets either with desirable ratios of $\omega$6/ $\omega$9 and P/M/S (mixed oil-fed group: MO) or with defficient in $\omega$3 series fatty acids (safflower oil-fed group: SO) on the oleic acid composition in RBC and brain synaptosomal, mitochondrial & microsomal phospholipids. The desirable fatty acid composition was computer-searched with different fats and oils to meet right ratios of both $\omega$6/ $\omega$3 and P/M/S. Diets were fed 3 weeks before conception and new-born pups were fed maternal milk from the same mothers and same diets until 9 wks of age. At 3 wks of age, the compositions of oleic acid in brain subcellular fractions and red blood cells were constantly remained whatever the composition of dietary fatty acids. But at 9 wks of age, the composition of oleic acid in synaptosome and mitochondria were significantly higher in MO group than SO group. The composition of oleic acid in milk was significantly higher in MO group than SO group, but in case of SO group, that of oleic acid was increased by 48%, in comparison with dietary fatty acid compositions. -9 desaturase index (18:0\longrightarrow8:1) of brain synaptosome was significantly higher in MO group than SO group at 3 and 9 weeks of ages, but that of brain microsome was higher in SO group than MO group at 9 wks of age. Taken together, the presences of oleic acid in the diet was important to maintain brain functions. The origins of oleic acid in brain may suggests two hypotheses; first, the central nervous system has priority for the uptake of oleic acid, and second the nervous system can synthesize all the oleic acid it needs, independently of its presence in the diet.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1466-1472
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• 2008

Variations in conjugated linoleic acid (CLA) concentrations in Holstein dairy cows milk, depending on feeding systems in different seasons was investigated. Milk samples were collected from Holstein dairy cows, which either grazed for whole days (WG), only daylight hours (TG), or were offered a total mixed ration (TMR) and experienced no grazing (NG), from April to December of 2005. In April, November and December, the cows in TG and WG treatments received grass silage and some concentrate, while from May to October, the cows grazed on temperate pasture. The cows in NG treatment received the TMR throughout the season. The major fatty acid obtained in the pastures was linolenic acid. There was no significant difference in the pasture's linolenic acid concentrations from May to September, but there was a significant decrease in October. However, the linolenic acid concentrations obtained in the pasture were always much higher than those obtained from the TMR. Linoleic acid was also the major fatty acid in the TMR, but these concentrations were higher in the TMR than in the pasture. There was no significant difference in milk cis9trans11CLA (c9t11CLA) concentrations between the three feeding systems while the cows were fed on conserved pasture in April, November and December. Although c9t11CLA concentrations were lower in the TMR, it was found that the cows which grazed in fresh pasture experienced significantly higher concentrations of c9t11CLA in their milk than those which received only TMR. It was also found that cows in the WG treatment experienced higher c9t11CLA concentrations than those in the TG treatment. In the WG and TG treatments, c9t11CLA concentrations were highest in June, after which, they gradually decreased (p<0.01) until October. For the NG treatment, there was no significant change in the concentrations of c9t11CLA (p>0.05) with season. Overall, trans11C18:1 and c9t11CLA were greatly influenced by season, with higher variation in the WG treatment than in the TG treatment and no variation in the NG treatment.

• Journal of Life Science
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• v.19 no.9
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• pp.1258-1264
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• 2009

In this study, effects of feeding Holstein cows with TMR feed, which includes un-dried citrus byproducts, on the nutritional components of their raw milk were investigated. Two kinds of raw milk from primipara cows and multipara cows were used for the experiment: T0 (raw milk produced by dairy cows not fed with TMR feed including citrus byproducts) and T1 (raw milk produced by dairy cows fed with TMR feed including citrus byproducts). For both primipara and multipara cows, there was no statistically meaningful difference between T0 and T1 in terms of moisture, crude protein, crude fat, crude ash contents or caloric content. T1 showed a lower amount of cholesterol in raw milk for both primipara and multipara cows, which was especially statistically meaningful in multipara cows (p<0.05). Regarding mineral contents in raw milk, T1 showed significantly higher amounts of Na and S in primipara cows, and Na, Cu, Fe, S in multipara cows, respectively. For both primipara and multipara cows, there were no statistically meaningful differences between T0 and T1 in terms of the total amount of amino acids in the raw milk, the composition of saturated fatty acid/unsaturated fatty acid, vitamin A, E, $B_2$ or $\beta$-carotene, while T1 showed significantly higher levels of vitamin $B_1$ in primipara cows than T0.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.8_spc
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• pp.1296-1305
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• 2019

There have been recent advances concerning research of the feeding and nutrition of dairy goats in a wide array of areas. Ruminally emitted methane and supplementary feedstuffs to a lesser extent make appreciable contributions to the carbon footprint of dairy goats, with the former affected by type of production system and associated dietary characteristics. Unique behavior of goats necessitates careful consideration of the nature of confinement facilities to achieve optimal production by animals differing in social hierarchy. Physiological conditions such as nutritional needs and perhaps health status may influence diet selection by goats in both grazing and confinement settings. Some research suggests that low concentrations of protein and fat in milk of high-yielding dairy goat breeds could involve the type and nature of dietary ingredients as influencing end products of ruminal fermentation. With the relationship between milk urea nitrogen concentration and efficiency of dietary protein utilization, through future research the measure may be a useful tool for diet formulation as in dairy cattle. Effects of dietary inclusion of sources of fats and oils vary considerably depending on their nature, as is also true for byproduct feedstuffs and conventional ones being substituted for. Supplementation of dairy goats with sources of polyunsaturated fatty acids can affect oxidative stress and various feedstuffs influence antioxidant status; however, research addressing the significance of such changes under practical production settings would be beneficial.

• Food Science and Industry
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• v.51 no.2
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• pp.148-156
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• 2018

Structured lipids are lipids in which the composition and/or positional distribution of fatty acids have been chemically or enzymatically modified from their natural biosynthetic form. Because structured lipids have desired nutritional, physicochemical, textural or physiological properties for applications in processed foods, functional foods, or nutraceuticals, many research activities have been aimed at their commercialization. The enzymatic production of structured lipids using lipases as the biocatalysts has a big potential in the future market due to the specificity or selectivity of the lipases. This article introduced some examples of specialty structured lipids that have been enzymatically produced and have been utilized as commercialized products. The commercialized products include medium- and long-chain triacylglycerols, human milk fat substitutes, cocoa butter equivalents, trans-free plastic fats, low-calorie fats/oils, and health-beneficial fatty acid-rich oils.

• Animal Bioscience
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• v.34 no.9
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• pp.1466-1478
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• 2021

Objective: Ruminants are completely dependent on their microbiota for rumen fermentation, feed digestion, and consequently, their metabolism for productivity. This study aimed to evaluate the rumen bacteria of lactating yaks with different milk protein yields, using high-throughput sequencing technology, in order to understand the influence of these bacteria on milk production. Methods: Yaks with similar high milk protein yield (high milk yield and high milk protein content, HH; n = 12) and low milk protein yield (low milk yield and low milk protein content, LL; n = 12) were randomly selected from 57 mid-lactation yaks. Ruminal contents were collected using an oral stomach tube from the 24 yaks selected. High-throughput sequencing of bacterial 16S rRNA gene was used. Results: Ruminal ammonia N, total volatile fatty acids, acetate, propionate, and isobutyrate concentrations were found to be higher in HH than LL yaks. Community richness (Chao 1 index) and diversity indices (Shannon index) of rumen microbiota were higher in LL than HH yaks. Relative abundances of the Bacteroidetes and Tenericutes phyla in the rumen fluid were significantly increased in HH than LL yaks, but significantly decreased for Firmicutes. Relative abundances of the Succiniclasticum, Butyrivibrio 2, Prevotella 1, and Prevotellaceae UCG-001 genera in the rumen fluid of HH yaks was significantly increased, but significantly decreased for Christensenellaceae R-7 group and Coprococcus 1. Principal coordinates analysis on unweighted UniFrac distances revealed that the bacterial community structure of rumen differed between yaks with high and low milk protein yields. Furthermore, rumen microbiota were functionally enriched in relation to transporters, ABC transporters, ribosome, and urine metabolism, and also significantly altered in HH and LL yaks. Conclusion: We observed significant differences in the composition, diversity, fermentation product concentrations, and function of ruminal microorganisms between yaks with high and low milk protein yields, suggesting the potential influence of rumen microbiota on milk protein yield in yaks. A deeper understanding of this process may allow future modulation of the rumen microbiome for improved agricultural yield through bacterial community design.

• Animal Bioscience
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• v.36 no.10
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• pp.1536-1545
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• 2023

Objective: The objective was to evaluate the effects of UV-B irradiated vitamin D-enriched yeast supplementation on milk yield, milk composition, vitamin D in milk, milk fatty acids, blood chemistry, and 25(OH)D status in dairy cows. Methods: Six Thai Friesian cows (milk production, 11.2±2.0 kg/d; body weight, 415.0±20.0 kg; and days in milk, 90.0±6.0) were allocated to each treatment in a 3×3 Latin square design, with three treatments and three periods. Each period of the Latin square lasted 49 days consisting of 14 days for diet adaptation and 35 days for sample collection. Dairy cows were randomly assigned to one of three treatments: i) feeding a basal diet without yeast (CON); ii) basal diet + 5 g of live yeast (75 IU/head/d of vitamin D₂; LY); and iii) basal diet + 5 g of UV-B irradiated vitamin D enriched yeast (150,000 IU/head/d of vitamin D₂; VDY). Feed intake and milk production were recorded daily, milk sample collection occurred on days 14 and 35 of each collection period, and blood plasma was collected on days 0, 7, 14, 21, 28, and 35 of each collection period. Results: The results show that after a trial period of 14 and 35 days, the VDY group had significantly higher vitamin D content in milk than the LY and CON groups (376.41 vs 305.15, 302.14 ng/L and 413.46 vs 306.76, 301.12 ng/L, respectively). At days 7, 14, 21, 28, and 35 of the experiment, cows fed the VDY group had significantly higher 25(OH)D₂ status in blood than the CON and LY groups (51.07 vs 47.16, 48.05 ng/mL; 54.96 vs 45.43, 46.91 ng/mL; 56.16 vs 46.87, 47.16 ng/mL; 60.67 vs 44.39, 46.17 ng/mL and 63.91 vs 45.88, 46.88 ng/mL), respectively. Conclusion: In conclusion, UV-B irradiated vitamin D-enriched yeast supplementation could improve vitamin D content in the milk and 25(OH)D status in dairy cows during the lactation period.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1256-1264
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• 2011

Infant formula is one of the main nutritional sources for infants. In this study, the fatty acid compositions of Korean (domestic, n=8) and foreign infant formulas (n=3) were analyzed. Crude fats were extracted using the Folch method, and fatty acid compositions (total and positional) were analyzed by gas chromatography. In the fatty acid compositions of infant formulas, oleic (19.88~44.64%), palmitic (7.59~21.65%) and linoleic acids (16.72~25.87%) were the major fatty acids. Domestic infant formula products contained 35.94~56.55% total saturated fatty acid content, whereas that of foreign infant formula ranged from 34.40~42.88%. The content of monounsaturated fatty acids ranged from 20.23~44.99% in domestic products and 34.11~45.07% in foreign products. In addition, 0.17~2.57% arachidonic acid/docosahexaenoic acid and 10~13% linoleic acid/linolenic acid were detected in the analyzed products (domestic and foreign products). A small amount of trans fatty acids (0.25~1.69%) were found. In sn-2 position analysis, palmitic acids (1.84~38.74%) were detected in the analyzed formulas. Further, typical triacylglycerols in human milk, including 1,3-di-monounsaturated-2-saturated triacylglycerol, were not detected in the analyzed formulas.

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.373-386
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• 2004

This study was conducted to investigate effects of the brown seaweed residues supplementation on in vitro fermentation, and milk yield and milk composition of dairy cows. Therefore, two experiments consisting of an in vitro and an in vivo growth trial were used. In in vitro experiment, brown seaweed residues(BSR) was supplemented in basal diet with 0, 1, 2 and 4% respectively, and incubated for 3, 6, 9, 12, and 24 h. The pH value, ammonia-N and VFA were investigated. The pH value tended to increase with increasing BSR during the incubation. Particularly, pH was significantly higher in BSR treatments compared with control at 9 h(p < 0.05). While, ammonia-N concentration was not significantly different across treatments during the whole incubation. BSR supplementation did not affect total VFA production, but acetate was linearly increased in BSR treatments compared with control at 12 h(p < 0.05), and its concentration was highest(92.70 mM) in 4% BSR among treatments. The concentration of iso-butyrate tended to increase in BSR treatments in comparison to control during the incubation. In addition, the concentration of iso-valerate was higher in BSR treatments compared with control at 12 and 24 h. In growth trial, BSR was added(800 g/d/animaI) to diets of dairy cow. Dry matter intake was not affected by BSR supplementation, but daily milk yield(kg) significantly increased in BSR treatment compared with control(p < 0.05). However, milk composition(%) and milk yield(kg) were not significantly different between treatments. Milk fat(% and kg/d) tended to slightly decrease in BSR treatment compared with control(3.59% and 1.06 kg/d vs. 3.32% and 1.01 kg/d), The contents of C16:0 and C20:4 in milk significantly increased in BSR treatment compared with control reflecting from dietary fatty acid composition. The content of C18:0 in milk which is end product of biohydrogenation of CI8 unsaturated fatty acids in the rumen significantly increased in BSR treatment compared with control(p < 0.05). C18:2 content in milk tended to decrease, but tended to increase trans-II C18:l and CLA contents in milk in BSR treatment compared with control. In conclusion, it could be summarized that BSR may stabilize rumen pH, and it could improve milk yield and CIA content in milk with more than 4% of diet. Therefore, BSR could be beneficially used in dairy diets as a feed additive.