• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1008-1017
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• 2021

This study was conducted to investigate the effect of different fattening periods on the growth performance, carcass characteristics, and economic traits of Holstein steers. Sixty Holstein steers (8.0 ± 0.28 months old) with an average body weight (BW) of 231.88 ± 2.61 kg, were randomly allocated to five different fattening period treatments: 20, 21, 22, 23, and 24 months (n = 12 in each treatment group). Final BW and average daily gain (ADG) did not differ among the treatment groups during the early fattening period. At the late stage of the fattening period, the final BW of steers in the 24-month treatment group (812.84 kg) was greater (p < 0.05) than that of steers in the 20-month treatment group (750.39 kg). During the same period, steers in the 20- and 21-month treatment groups had a significantly higher (p < 0.05) ADG than those in the 22-month treatment group. The highest ADG (1.36 kg/day) was found in the 20-month treatment group (1.36), followed by the 21- (1.33 kg/day), 22- (1.22 kg/day), 23- (1.21 kg/day), and 24- (1.14 kg/day) month treatment groups. The feed conversion ratio (FCR) increased as the fattening period increased, and the FCR was 12.88% lower in the 20-month treatment group than in the 24-month treatment group. However, no significant differences were detected in back-fat thickness, loin area, marbling score, and chemical characteristics (water, crude protein, and crude fat content) among the treatment groups. The composition of fatty acids including C18:0, C18:1, saturated fatty acids, unsaturated fatty acids, and poly-unsaturated fatty acids did not differ among the experimental groups. As the fattening period increased, production costs increased, resulting in a decrease in gross income. The gross income for steers in the 24-month treatment group was 35.8% and 23.5% lower than that for steers in the 20- and 21-month treatment groups, respectively. Taken together, the best performance, including the ADG, FCR, and gross income, was obtained when the fattening program of the Holstein steers lasted 20 months.

• Animal Bioscience
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• v.34 no.2
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• pp.295-305
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• 2021

Objective: The objectives of this study were to compare the effects of normal and low protein content (PC) of starter diet supplemented or not with blends of branched-chain amino acids (BCAAs) on growth performance of broilers under summer conditions and to investigate whether these effects altered some quality traits and the characteristics of gastrointestinal tract. Methods: A total of 768 mixed-sex broiler chicks (Ross 308, one-d-old) with an average initial body weight (BW) of 47.6±1.03 g were allocated into six treatments with four replications in 2×3 factorial arrangement. Factors were: PC, normal (N, 22% to d 15); and low (L, 20% to d 15); and added BCAA blends, L-leucine, L-isoleucine, and L-valine at zero (0L:0I:0V); 1.0, 0.25, and 0.25 (4L:1I:1V); or 1.0, 0.25, 0.75 (4L:1I:3V) g/kg of diet. Hence, six dietary treatments were named as N0L:0I:0V, N4L:1I:1V, N4L:1I:3V, L0L:0I:0V, L4L:1I:1V, and L4L:1I:3V. Average indoor temperature and humidity were 32.8℃±1.7℃ and 61.1%±4.12%, respectively. Results: BW, feed conversion ratio (FCR) and carcass weight were not affected by PC, BCCA and their interaction (p>0.05). The L diets decreased the water holding capacity of the breast (p = 0.002) and thigh (p = 0.050) meats and dressing percentage (p = 0.005) compared to the N diets. The 4L:1I:1V diet decreased breast yield compared to the 0L:0I:0V diets (p = 0.041). The effect of PC on feed intake, mortality and gastrointestinal trait weight were depended on the L:I:V ratios under summer conditions due to interactions between factors (p<0.05). The FI and mortality of L4L:1I:1V broilers were lower than those of N4L:1I:1V birds (p<0.05). Conclusion: It was concluded that the blends of BCAAs used failed to improve performance and to promote breast yields, because diets with normal or with reduced protein supplemented or not with BCAAs up to d 15 produced a similar BW and FCR in broilers raised in hot-climate conditions.

• Nutrition Research and Practice
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• v.15 no.3
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• pp.355-366
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• 2021

BACKGROUND/OBJECTIVES: The study was performed to investigate health-related lifestyle, dietary habits, and depression according to exercise frequency to understand complex factors that affect effective health management. Thus, exercise frequency, health-related lifestyle, dietary habits, and depression were evaluated in college students in Seoul and Gyeonggi-do areas. SUBJECTS/METHODS: A survey was conducted on college students, aged 19-29, in Seoul and Gyeonggi-do areas from May 13 to May 31, 2020. A total of 594 questionnaires were collected and 566 (269 from males, 297 from females) were statistically analyzed, except 28 with incomplete responses. Collected data were analyzed using SPSS WIN 21.0 program. RESULTS: The sex distribution of the 3 groups according to exercise frequency was significantly different; the ratio of males in over 3 times/week group was significantly higher than those in 1-2 times/week group and no-exercise group (P < 0.001). The height (P < 0.001), weight (P < 0.001), and body mass index (P < 0.05) were significantly higher in over 3 times/week group compared to no-exercise group. The ratio of subjects who answered 'good' or 'very good' for subjective health condition was significantly high in the order of 'over 3 times/week' group (59.1%), '1-2 times/week' group (34.5%), and 'no-exercise' group (25.0%) (P < 0.001). The ratio for meal regularity was high as 56.6% in 'over 3 times/week' group and the ratio for irregular meals was significantly higher in 'no-exercise' group (67.2%) and '1-2 times/week' group (54.9%) (P < 0.001). Among questions on dietary habits, 'Eat meat, fish, egg or beans' (P < 0.01) and 'Eat fruit' (P < 0.01) were significantly higher in 'over 3 times/week' group compared to 'no-exercise' group. 'Drink more than 2 liters of water' (P < 0.001) was 0.70 in 'over 3 times/week' group, which was significantly higher than 0.54 in '1-2 times/week' group and 0.38 in 'no-exercise' group. Moderate depression and severe depression that need treatments were significantly lower in 'over 3 times/week' group (18.7%) compared to '1-2 times/week' group (26.0%) and 'no-exercise' group (29.7%) (P < 0.05). CONCLUSIONS: It is considered that combined intervention for exercise habits, proper dietary habits, and depression management is needed for effective health management.

• Herbal Formula Science
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• v.29 no.2
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• pp.71-80
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• 2021

Objectives : This study investigated cellular-protective effects of Nardotidis seu Sulculii Concha water extract (NSCE) against oxidative stress induced by arachidonic acid (AA)+iron or tert-butylhydroperoxide (tBHP). Methods : In vitro, MTT assay was assessed for cell viability, and immunoblotting analysis was performed to detect expression of AMP-activated kinase (AMPK) signaling pathway and autophagy related proteins. In vivo, mice were orally administrated with the aqueous extract of NSCE of 500 mg/kg for 3 days, and then injected with CCl₄ 0.5 mg/kg body weight to induce acute damage. The level of liver damage was measured by serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) analysis. Results : Treatment with NSCE inhibited cell death induced by AA+iron and tBHP. NSCE induced the phosphorylation of AMPK, and this compound also induced the phosphorylation of LKB1, an upstream kinase of AMPK, and Acetyl-CoA carboxylase (ACC), a primary downstream target of AMPK. NSCE increased the protein levels of autophagic markers (LC3II and beclin-1) and decreased the phosphorylation of mammalian target of rapamycin (mTOR) and simultaneously increased the phosphorylation of unc-51-like kinase-1 (ULK-1) in time-dependent manner. Conclusions : NSCE has the ability 1) to protect cells against oxidative stress induced by AA+iron or tBHP. NSCE 2) to activate AMP-activated protein kinase (AMPK), and 3) to regulate autophagy, an important regulator in cell survival.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.232-239
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• 2011

This study was performed to find out the persimmon vinegar as a functional drink on reducing blood lipids and enhancing exercise performance. For these, thirty two Sprague-Dawley male rats were divided into 4 groups; control (CONT), water placebo with high fat diet control (ACON), high fat diet with 2.5 times diluted persimmon vinegar ingestion (PV2.5), and high fat diet with 5.0 times diluted persimmon vinegar ingestion (PV5.0). Body weight was not different. Abdominal fat pads were statistically reduced in PV2.5 and PV5.0 compared to CONT and ACON. Blood glucose was not significant but TC, LDL-C and TG were lower in PV2.5 and PV5.0 than other groups, and HDL-C in PV2.5 was the highest among groups. Glycogen contents in the muscle and liver were higher in PV2.5 and PV5.0 compared to CONT and ACON. These results suggested that persimmon vinegar ingestion may inhibit the blood lipids increase and increase glycogen storage which possibly enhancing exercise performance. Therefore, persimmon vinegar has the possibility as the functional drink.

• Composites Research
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• v.33 no.6
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• pp.365-370
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• 2020

The icing formation at aircraft occur problems such as increasing weight of the body, fuel efficiency reduction, drag reduction, the error of sensor, and etc. The viscosity of polyurethane (PU) topcoat was measured at 60℃ in real time to set the pre-curing time. SiO2 nanoparticles were dispersed in ethanol using ultra-sonication method. The SiO2/ethanol solution was sprayed on PU topcoat that was not cured fully with different pre-curing conditions. Surface roughness of SiO2/PU nanocomposites were measured using surface roughness tester and the surface roughness data was visualized using 3D mapping. The adhesion property between SiO2 and PU topcoat was evaluated using adhesion pull-off test. The static contact angle was measured using distilled water to evaluate the hydrophobicity. Finally, the pre-curing time of PU topcoat was optimized to exhibit the hydrophobicity of SiO2/PU topcoat.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.2
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• pp.109-117
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• 2022

There has been an increasing number of studies on photovoltaic energy generation system in an offshore site with the largest energy generation efficiency, as increasing the researches and developments of renewable energies for use of offshore space and resources to replace existing fossil fuels and resolve environmental challenges. For installation and operation of floating photovoltaic systems in an offshore site with harsher environmental conditions, a stiffness of structural members comprising the total system must be reinforced to inland water spaces as dams, reservoirs etc., which have relatively weak condition. However, there are various limitations for the reinforcement of structural stiffness of the system, including producible size, total mass of the system, economic efficiency, etc. Thus, in this study, a floating breakwater is considered for reducing wave loads on the system and minimizing the reinforcement of the structural members. Wave reduction performances of floating breakwaters are evaluated, considering size and distance to the system. The wave loads on the system are evaluated using the higher-order boundary element method (HOBEM), considering the multi-body effect of buoys. Stresses on structural members are assessed by coupled analyses using the finite element method (FEM), considering the wave loads and hydrodynamic characteristics. As the maximum stresses on each of the cases are reviewed and compared, the effect of floating breakwater for floating photovoltaic system is checked, and it is confirmed that the size of breakwater has a significant effect on structural responses of the system.

• Animal Bioscience
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• v.35 no.7
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• pp.1069-1079
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• 2022

Objective: The objective of this study was to investigate the effect of 4-month intensive feeding on the meat quality, fatty acid profile, flavor, and growth performance of grazing Hulunbuir sheep (HBS). Methods: The HBS were selected 4-months after birth in a pasture rearing system as the experimental animals (n = 44, female, average body weight 23.8±2.2 kg) then divided equally into pasture-based grazing fattening (PAS) and concentrate-included intensive fattening (CON) groups for another 4-month finishing. When finished fattening, all animals were slaughtered to collect musculus longissimus dorsi subcutaneous adipose tissue and to investigate the influences on meat quality, fatty acid profile, flavor and growth performance. Results: The results showed lambs in CON group got significantly higher live weight, hot carcass weight, and dressing percentage. The CON group had significantly higher value of redness (a^*), lightness (L^*) and water holding capacity (p<0.05), significantly lower value of Warner-Bratzler shear force than the PAS group (p<0.05). The subcutaneous fat from CON group lambs demonstrated a significantly higher content of C18:1 and C18:2 (p<0.05), but lower C14:0 and C16:0, indicating an increased degree of unsaturated fatty acid. The content of 4-methyloctanoic acid, 4-ethyloctanoic acid and 4-methylnonanoic acid had increased 2 to 4 times, representing a more intense odor in the CON group. However, the values were still lower than most sheep breeds reported, indicating the indoor feeding system could not fundamentally deteriorate the excellent meat characteristic of HBS. Conclusion: It was evident that lambs in CON group exhibited a better meat production performance, improved in meat color, texture and healthier fatty acid profile through pasture-weaned concentrate included intensive fattening system, which offers a good alternative regimen for lamb finishing and has a wide prospection in the HBS meat industry.

• The Korea Journal of Herbology
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• v.37 no.4
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• pp.49-57
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• 2022

Objective : This study was conducted to investigate antidiabetic effects of chunggugjang with medicinal herbal complex (CJ) in streptozotocin (STZ)-induced animal models. Method : STZ (65 mg/kg) was injected intraperitoneally to induce diabetes. Then rats were divided into 5 groups ; NG (normal diet + 0.9% saline), COS (STZ +saline 5 mL/kg), COB (STZ + fermented soybean(100 mg/kg), CJ 100/200 (STZ+CJ(100 and 200 mg/kg), CJ 300/600 (STZ+CJ(300 and 600 mg/kg). 4 weeks later, oral glucose tolerance test (OGTT) was performed. After sacrificing rats, serum levels of blood urea nitrogen (BUN), creatinine, aspartate amino transferase (AST), alanine amino transferase (ALT), total cholesterol (TC), and triglyceride (TG) were measured and histological changes were observed. Result : Body weight change and food efficiency ratio (FER) were decreased in the CJ 300/600 group than in the COS group. But, there was no change in water intake. Serum levels of glucose, AST, ALT and BUN were lower in the CJ 300/600 group than in the COS group. Also, TG, TC, and creatinine were decreased in the CJ 300/600 group than in the COS group. According to OGTT, 120 minutes postprandial glucose levels were lower in the CJ 300/600 group than in the COS group. In addition, administration of CJ extracts restored histopathological damage. Conclusion : The results suggest that CJ can be used as a functional material for diabetes treatment as it has the effect to improve pathological symptoms in STZ-induced diabetic rats.

• Korean Journal of Organic Agriculture
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• v.29 no.2
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• pp.241-256
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• 2021

The current study was to evaluate the antioxidant activity of Phyllostachys bambusoides (PHB) as a feed additives and investigate whether its antioxidant activity could be helpful for increasing rumen fermentation characteristics and methane reduction. The antioxidant activity results showed that total polyphenols and flavonoids contents were 43.54 ± 8.68 mg CE/g and 17.13 ± 0.45 mg QE/g, respectively, and the IC₅₀ values for 1,1-diphenyl-2-prcrylhydrazyl (DPPH) and 2,2'-azino-bis (3- ethylbenzthiazoline-6- sulphonic acid) (ABTS) radical scavenging activity were 163.13 ± 19.25 ㎍/mL and 97.07 ± 4.46 ㎍/mL, respectively. Two heads of cannulated Hanwoo (450 ± 30 kg), consuming timothy hay and a commercial concentrate (60:40, w/w) twice daily (at 09:00 and 17:30) at 2% of body weight, with free access to water and a mineral block, were used as rumen fluid donors. An in vitro incubation experiment was performed after 6, 12, 24, 48, and 72 hr with PHB added at concentration of 2, 4, and 6% of timothy hay basis. Total gas emission decreased as the amount of PHB addition increased at 6 and 24 hr of incubation. However, PHB addition did not affect total volatile fatty acid production, and methane and carbon dioxide emission also decreased as the amount of addition increased at 48 hr of incubation. Therefore, PHB was expected to be used as methane reducing additives in the ruminants.