• Korean Journal of Ecology and Environment
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• v.49 no.2
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• pp.80-88
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• 2016

In order to reconstruct a benthic foodweb structure and assess the role of benthic microalgaes as a diet source for benthos, we analyzed the carbon and nitrogen stable isotopes of diverse benthos (bivalves, crustaceans, gastropods and fishes) and potential diets (particulate organic matter, sedimentary organic matter, benthic microalgae, seagrass, and macroalgaes) in the intertidal mudflat surrounding Yeongheung Island. The ${\delta}^{13}C$ values of the diets indicated wide ranges (- 26.5‰ to - 8.4‰) while benthos showed a small range of ${\delta}^{13}C$ values (-12.1‰ to - 17.8‰), although they were in the same range. Except for green algaes among the macroalgaes as well as sedimentary organic matter, ${\delta}^{15}N$ values of the diet candidates ($5.7{\pm}1.0$‰) were lighter in comparison to those of the benthos ($11.8{\pm}1.9$‰). Based on the ${\delta}^{13}C$ and ${\delta}^{15}N$ data, the benthos were classified into 3 groups, indicating a different diet and trophic position. But benthic microalgae is the most important diet source for all three benthos groups based on their stable isotope ratios, suggesting benthic microalgae should be a main diet to the intertidal ecosystem. Hence this study highlights that the biomass of benthic microalgae as biological resource should be evaluated for the management of the intertidal ecosystem of Yeongheung Island.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.1
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• pp.35-43
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• 2020

Objective: The aim of this research was to evaluate the effect of different concentrate levels in diets based on cactus Opuntia Stricta (Haw.) Haw cladodes on the performance of lactating Girolando cows. Methods: The experiment involved 10 Girolando multiparous dairy cows at 512.6 kg of body weight (BW) and producing 13.2 kg milk/d, allocated into two 5×5 Latin squares. The experimental treatments consisted of control diet composed by cactus Nopalea cochenillifera. Salm-Dyck. cladodes (Nopalea), forage sorghum silage and concentrate at 20% on dry matter (DM) basis, and four concentrate levels diets (20%, 24%, 28%, and 32%) plus cactus Opuntia stricta (Haw.) Haw. cladodes (Opuntia) and forage sorghum silage. Results: Regarding cows fed control diet, the nutrients intake were greater than for cows fed with cactus Opuntia and concentrate. Regarding concentrate levels, intakes of DM, organic matter (OM), crude protein (CP), non-fiber carbohydrates (NFC), and total digestible nutrients of cows increased linearly. Organic matter, CP, and NDF digestibilities were similar in between to control diet and cactus Opuntia-based diets. The digestibility of NFC increased linearly when the concentrate was inserted. The N balance was the same for control diet and cactus Opuntia-based diets, irrespective the concentrate levels. Conclusion: For cows producing 14 kg/d with 3.5% of fat, it is recommended 32% of concentrate to be included in cactus Opuntia-based diets, and the increase in concentrate level promotes a linear increase in milk yield.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1191-1197
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• 2002

This experiment was conducted to study the effects of replacing corn with Chinese brown rice on performance and apparent fecal digestibility of nutrients in weanling pigs. Seventy-two cross-bred (Duroc${\times}$Landrace${\times}$Large White) weanling pigs, weighing an average of $7.38{\pm}0.06kg$, were randomly assigned to either a corn-soybean meal diet (treatment 1), a corn-brown ricesoybean meal diet (treatment 2) and a brown rice-soybean meal diet (treatment 3). The brown rice used in this experiment was husked from one kind of early, long grain, non-glutinous rice (ELGNR, indica rice). The growth performance of weanling pigs in the experiment was similar during weeks 1 and 2, but feed conversion ratio (FCR) was significantly better in treatment 2 during weeks 3 and 4. During week 2, only the digestibility of organic matter in treatments 2 and 3 was significantly higher than that in treatment 1. During week 4, the digestibility of gross energy, ether extract, organic matter and dry matter in brown rice treatment, especially in treatment 3, were significantly higher than in treatment 1. At the end of the experiment, the concentration of serum urea nitrogen of pigs in treatment 2 was lower than that in treatment 1 and 3 and no difference was found in serum glucose and phosphorus. It could be concluded from this experiment that replacing 50% of corn with brown rice in the corn-soybean meal diet caused no negative effects to weanling pig performance, and apparent fecal digestibility was unaffected. It is feasible to replace corn with brown rice in weanling pig diets in southern China.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.491-500
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• 2010

Three experiments were conducted to investigate the effects of polyurethane coated urea on in vitro ruminal fermentation, ammonia release dynamics and lactating performance of Holstein dairy cows fed a steam-flaked corn-based diet. In Exp. 1, a dual-flow continuous culture was run to investigate the effect of polyurethane coated urea on nutrient digestibility, rumen fermentation parameters and microbial efficiency. Three treatment diets with isonitrogenous contents (13.0% CP) were prepared: i) feedgrade urea (FGU) diet; ii) polyurethane coated urea (PCU) diet; and iii) isolated soy protein (ISP) diet. Each of the diets consisted of 40% steam-flaked corn meal, 58.5% forages and 1.5% different sources of nitrogen. PCU and FGU diets had significantly lower digestibility of NDF and ADF (p<0.01) than the ISP diet. Nitrogen source had no significant effect (p = 0.62) on CP digestibility. The microbial efficiency (expressed as grams of microbial N/kg organic matter truly digested (OMTD)) in vitro of the PCU diet (13.0 g N/kg OMTD) was significantly higher than the FGU diet (11.3 g N/kg OMTD), but comparable with the ISP diet (14.7 g N/kg OMTD). Exp. 2, an in vitro ruminal fermentation experiment, was conducted to determine the ammonia release dynamics during an 8 h ruminal fermentation. Three treatment diets were based on steam-flaked corn diets commonly fed to lactating cows in China, in which FGU, PCU or soybean meal (SBM) was added to provide 10% of total dietary N. In vitro $NH_3-N$ concentrations were lower (p<0.05) for the PCU diet than the FGU diet, but similar to that for the SBM diet at all time points. In Exp. 3, a lactation trial was performed using 24 lactating Holstein cows to compare the lactating performance and blood urea nitrogen (BUN) concentrations when cows were fed PCU, FGU and SBM diets. Cows consuming the PCU diet had approximately 12.8% more (p = 0.02) dietary dry matter intake than those consuming the FGU diet. Cows fed the PCU diet had higher milk protein content (3.16% vs. 2.94%) and lower milk urea nitrogen (MUN) concentration (13.0 mg/dl vs. 14.4 mg/dl) than those fed the FGU diet. Blood urea nitrogen (BUN) concentration was significantly lower for cows fed the PCU (16.7 mg/dl) and SBM (16.4 mg/dl) diets than the FGU (18.7 mg/dl) diet. Cows fed the PCU diet had less surplus ruminal N than those fed the FGU diet and produced a comparable lactation performance to the SBM diet, suggesting that polyurethane coated urea can partially substitute soybean meal in the dairy cow diet without impairing lactation performance.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.4
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• pp.527-532
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• 2019

Objective: Phosphorous (P) sources with greater bioavailability might increase animal production efficiency and decrease environmental pollution. The objective of current study was to determine animal performance, nutrient digestibility, blood metabolites and fecal P concentration in finishing lambs fed a diet with either di-calcium phosphate (DCP) or di-ammonium phosphate (DAP) as a P source. Methods: Twelve 4-month-old male lambs (initial body weight $24.87{\pm}3.4kg$) were randomly allocated to a diet with either DCP or DAP (~261 g/kg of total diet P) fed ad libitum for 93 days. Diets were iso-nitrogenous and iso-energetic and had same calcium (Ca) and P concentrations. Results: The DAP contained 19.7 g/kg of dry matter (DM) Ca, 185.4 g/kg DM P and 14,623 ppm fluorine, while DCP contained 230.3 g/kg DM Ca, 195.2 g/kg DM P and 1,039 ppm fluorine. The diet with DAP contained 60 ppm fluorine while the diet with DCP contained 13 ppm fluorine. Lambs fed the diet with DAP tended to have a greater daily DM intake compared to those fed diet with DCP (p = 0.09). Lambs fed DAP had greater plasma P concentration and alkaline phosphatase activity ($p{\leq}0.01$) compared with lambs fed DCP. Dry matter and organic matter digestibility of the diets were similar between two treatments at days 60 and 90, while they were greater in lambs fed DCP (p<0.05) at day 30 of the trial. Feeding DAP increased P digestibility (58.7% vs 50.2%; p<0.05) and decreased fecal P concentration in lambs compared with feeding DCP (3.1 vs 3.8 g/kg DM; p<0.05). Conclusion: Providing ~261 g/kg of total diet P as DAP in the diet of finishing lambs improved the bioavailability of P in the body and decreased excretion of P in feces without affecting lamb performance.

• Journal of Nutrition and Health
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• v.20 no.2
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• pp.135-144
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• 1987

This study was carried out to investigate the effect of dietray carbohydrate level on the lipid and Ca metabolism, and on immune response in the process of aging. Sprag\ulcornerue - Dawley male rats of 12 months of age were fed either high carbohydrate or low carbohydrate diet for 9 months. With increasing age from 12 months to 21 months, there was no significant increase in body weight, however, the epididymal fat pat weight and total serum lipid tend to become higher, and the inorganic/organic matterratio in bone tends to become lower. This suggests that body fat accumulation increase and bone mass decrease with age. Rats fed low carbohydrate diet showed the higher epididymal fat pat weight, and the lower Ca content in femur and scapular compared to high carbohydrate diet fed rats. The immune response was also lower in low carbohydrate diet group judged by the lower thymus and spleen index and by the lower response to PHA and ConA stimulation. The results of this study suggests that the dietary level of carbohydrate and fat may play an important role in the process of aging. It could be recommended to practice high carbohydrate -low fat diet for the elderly to reduce the risk of degenerative diseases.

• Korean Journal of Organic Agriculture
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• v.17 no.2
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• pp.237-251
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• 2009

This study was carried out to evaluate the effect of replacing antibiotics by organic acid mixture on growth performances and blood metabolites in growing pigs. Twenty-five crossbred pigs (Large White${\times}$Landrace) at the age of 79 days were fed five different diets by supplementing organic acid mixture and chlortetracycline. The experimental diets were consisted of diets without antibiotics supplementation (control), diets added 100mg/kg of chlortetracycline to control diet (T1), diets added 100mg/kg of chlortetracycline and 0.1% of $Acidomix^{(R)}$ (comprising formic acid 25%, sorbic acid 10%, fumaric acid 10%) to control diet (T2), diets added 0.1% of $Acidomix^{(R)}$ to control diet (T3), and diets added 0.3% of $Acidomix^{(R)}$ to control diet (T4). The changes in feed conversion ratio, average daily gain and blood metabolites were investigated. Twenty-five pigs were allotted to five treatments with five replications of each and the experiment was conducted on the basis of complete randomized design for 6 weeks. Average daily gain was significantly (p<0.05) different between T4 and control diets. All treatments including diets added $Acidomix^{(R)}$ and chlortetracycline were slightly higher than control diets. The feed intakes did not show a significant difference between the control and other treatments, and did not give change in feed intake by the addition of $Acidomix^{(R)}$. No differences on feed conversion ratio among treatments were observed but T4 and T3 treatments showed lower value than other treatments. The concentrations of blood urea nitrogen, total cholesterol and triglyceride were significantly (p<0.05) different among treatments, but their values were within the normal range representing that effects on blood profile by organic acid or antibiotics supplementation were not found. The results from this study indicated that adding chlortetracycline or organic acid mixtures to diets showed tendency to improve average daily gain and feed conversion ratio in growing pigs. These results showed that antibiotics could be replaced by organic acid mixture in growing pig diets, leading to stimulated growth and improved feed conversion ratio.

• Journal of the korean society of oceanography
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• v.35 no.2
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• pp.124-127
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• 2000

The analysis of stable carbon isotope ratios for benthic fauna was applied to identify the source of carbon in benthic food webs in Youngil Bay, Korea. The ${\delta}^{13}$C values of 9 invertebrate species collected in this area showed a narrow range between -20.5 and -16.3%$_o$ with a mean of-18.1 (${\pm}$1.1)"%$_o$. The results suggest that the major source of organic carbon for the benthic fauna of the lower estuarine reaches and the oceanic sites is autochthonous marine particulate organic matter. The contribution of organic matter from terrestrial and riverine sources to the diet of the benthic fauna in this area appears to be minor, despite the considerable inflow of riverine waters.

• Korean Journal of Organic Agriculture
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• v.16 no.2
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• pp.205-218
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• 2008

This study was conducted to evaluate the effects of dietary pitamin, pine bark extracts, as a organic livestock feed additives on the egg production and egg quality of laying hens. One hundred-fifty laying hens (Hyline brown) were randomly allocated to one of the following 3 treatment groups for 6 weeks: control, pitamin 0.1% and pitamin 0.2%. The egg production of hens fed the diet containing 0.1% pitamin was similar to that of the control; however, the egg production of the pitamin 0.2% group was significantly lower than that of the other groups (p<0.05). Additionally, the Haugh unit was higher in groups fed diets that contained 0.1% or 0.2% pitamin than in the control group (p<0.05), but no significant difference in egg shell thickness and egg shell breaking was observed between the pitamin 0.1% group and the control group. Furthermore, the concentration of cholesterol in eggs produced by the pitamin 0.1% group was significantly lower than that of the other groups (p<0.05). Moreover, the saturated fatty acid content of eggs from hens in the pitamin 0.2% group was lower than that of eggs produced by hens in the other groups, whereas the unsaturated fatty acid content of eggs produced by hens in the pitamin 0.2% group was higher than that of eggs produced by hens in the other groups (p<0.05). Finally, the values corresponding to the storage days, Haugh unit, yolk index and albumin index of eggs produced by hens that were provided with a diet that contained 0.1% or 0.2% pitamin were significantly higher than those of the control group (p<0.05). Taken together, these results suggest that providing hens with a diet supplemented with 0.1% pitamin as a organic livestock feed additives may extend the shelf-life of eggs with maintaining the egg quality and egg production in laying hens.

• Korean Journal of Organic Agriculture
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• v.25 no.1
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• pp.219-231
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• 2017

The aim of this study was to determine the effects of feeding of different organic diets (based on fatty acid contents) on CLA and fatty acid concentration of raw milk. Total two hundred and ninety Holstein cows were divided into control, treatment 1 and treatment 2 groups according to the parity and milk yield. Control diet was contained higher C16:00, C18:2 and SFA. Treatment 1 diet was higher in C18:1, C18:2, UFA and treatment 2 diet was higher in MUFA and C18:3 and PUFA. The results indicated that the C16:0 concentration in raw milk was greater in the group of treatment 2 than in control and treatment 1 (p<0.05). The concentration of CLA in treatment 2 was higher compared to treatment 1 and control groups (p<0.05). The ration of n-3/n-6 was higher in treatment 2 group compared with control and treatment 1 (p<0.05). In conclusion, feeding 100% of grass feed for dairy cows increases CLA and n-3 content in milk. From now on, basis on our study, development of functional milk will increase a health of children and old people.