• Journal of Environmental Science International
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• v.32 no.1
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• pp.77-88
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• 2023

Kadsura coccinea (Lem.) A.C. Smith is used as a medicinal plant and cosmetic material in China and Southeast Asia. To mass-produce Kadsura coccinea seedlings, the effects of gibberellic acid (GA₃) and cold stratification treatments on seed germination were investigated. Seed germination rate with GA₃ treatment was most effective at concentrations of 250 or 500 mg/L. With respect to mean germination time (MGT), mean daily germination, and T₅₀ (days to reach 50% seed germination), the germination-promoting effect was improved as the concentration of GA₃ increased. Stem growth of seedlings was the highest following GA₃ treatments of 250 and 500 mg/L, and the growth promoting effect gradually decreased as the concentration of GA₃ decreased. Root growth was stimulated at GA₃ concentrations of 250-1,000 mg/L. Examination of the effect of stratification treatment for 15, 30 and 60 days at temperatures of 0, 5 and 10℃ on the germination rate revealed that the most stratification treatment temperature was 10℃, and the results improved with longer treatment periods. Altogether, GA₃ and stratification treatments improved the seed germination rate, shortened the MGT, improved germination uniformity, and produced healthy seedlings.

• Journal of Animal Science and Technology
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• v.64 no.3
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• pp.462-470
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• 2022

The addition of dietary proteases (PRO) to weaner diets hydrolyzes soybean-based anti-nutritive factors and improves weaned pig's dietary digestibility and growth performance. Therefore, this study explores the effects of PRO in a lower crude protein (CP) level diet than that in a commercial diet on the growth performance, nutrient digestibility, and intestinal morphology of weaned pigs. A total of 90 weaned pigs were randomly assigned to 3 dietary treatments with 6 pigs per pen and 5 replicated pens per treatment using a randomized complete block design (block = body weight [BW]): 1) a commercial weaner diet as a positive control (PC; phase1 CP = 23.71%; phase2 CP: 22.36%), 2) lower CP diet than PC as a negative control (NC; 0.61% less CP than PC), and 3) an NC diet with 0.02% PRO. Pigs fed PC and PRO had higher (p < 0.05) final BW, average daily gain, and/or gain to feed ratio for the first three weeks and the overall experimental period than NC. The PC and PRO groups had greater (p < 0.05) apparent ileal digestibility of dry matter, CP, and energy than the NC group. Moreover, pigs fed PC and PRO increased (p < 0.05) apparent total tract digestibility of CP compared with those fed NC. In addition, the PRO group had a higher number of goblet cells than the PC and NC groups. However, pig fed PC and PRO increased (p < 0.05) villus height and height to crypt depth ratio in the ileum compared with those fed NC. In conclusion, PRO supplementation in a commercial weaner diet with low CP levels improves growth rate and nutrient digestibility by modulating the intestinal morphology of weaned pigs.

• Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.123-129
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• 2011

To determine whether rearing density affects the hypermelanosis on the blind side (ambicoloration) of olive flounders Paralichthys olivaceus, we reared fry with an unpigmented non-eyed (blind) side in duplicate at densities of 150 individuals/$m^2$ (commercial production density: control) and 450 individuals/$m^2$ (high density group) for 90 days in 1-t dark-green fiberglass reinforced plastics (FRP) tank. We recorded feed intake, feed conversion efficiency (FE), growth and survival, and measured the ratios of staining blind-side area (staining area) and ambicolored fish every 30 days. Daily feed intake (DFI), feed conversion efficiency (FE), growth rate, condition factors, and survival rate were calculated at the end of the experiment. Although the FE was higher in the high-density compared to the control, the two density groups showed similar feed intakes, growth, and survival. The ratio of staining area as well as the ratio of ambicolored fish significantly were significantly higher in the high-density group than in the control from days 30 to 60, but significantly increased and evened out by the end of the experiment (P<0.05). In conclusion, we determined that rearing density is not the main cause of the blind-side hypermelanosis, but found that increasing the rearing density can accelerate the ambicoloration in olive flounders.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.6
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• pp.680-684
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• 1998

The effect of feeding heifers young Napier grass (7-weeks regrowth) or old Napier (16-weeks regrowth) supplemented with either wilted Desmodium intortum, Sesbania sesban or dried Calliandra calothyrsus leaves on intake and live weight changes was evaluated in a 67-day trial. Thirty-two Friesian heifers with an average live weight of 271 kg and 16.8 months old were randomly allocated to the four diets. The diets were either ad libitum young Napier grass or old Napier grass supplemented with 25% of either Sesbania, Desmodium or Calliandra. There was significant difference in chemical composition between the young and old Napier grass. Significant differences (p < 0.05) were observed on intake of dry matter, organic matter, crude protein and neutral detergent fibre. The total dry matter intake was 2.77, 2.86, 2.62 kg/100 kg live weight (LW) for Desmodium, Calliandra and Sesbania supplemented diets, respectively. A dry matter intake of 3.11 kg/100 kg LW was observed on the heifers fed young Napier grass. The mean daily gains were 638, 732, 606, and 1,001 g/day for Desmodium, Calliandra, Sesbania supplemented and young Napier grass diets respectively. Low level supplementation rate (1-1.5 kg DM/day) was adequate to maintain good growth rate when the heifers were fed old Napier grass.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.4
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• pp.183-186
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• 2007

The effect of live food and commercial diet on sweetfish Plecoglossus altivelis culture was assessed by determining the daily growth rate and feed conversion ratio. After feeding for 8 weeks, the Moina macrocopa diet resulted in a higher growth rate of 5.101 compared to commercial (3.441) and Artemia (2.729) diets. In addition fish fed the M. macrocopa diet had the weight gain, averaging 41.29 g at the end of the experiment. The content of n-3 highly unsaturated fatty acids (HUFA) was highest in the commercial diet, while free fatty acids were not detected in the M. macrocopa diet. Triglycerides, the energy source in fishes, constituted 40.0% of the M. macrocopa diet, which was significantly higher than in the commercial and Artemia diets at 20.0 and 12.0%, respectively These results indicate that freshwater M. macrocopa can be used as feed for sweetfish larvae, even without docosahexaenoic acid (DHA) enrichment from Artemia.

• Fisheries and Aquatic Sciences
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• v.20 no.5
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• pp.7.1-7.6
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• 2017

A feeding trial was designed to assess the effects of dietary protein and lipid content on growth, feed utilization efficiency, and muscle proximate composition of juvenile mandarin fish, Siniperca scherzeri. Six experimental diets were formulated with a combination of three protein (35, 45, and 55%) and two dietary lipid levels (7 and 14%). Each diet was fed to triplicate groups of fish ($8.3{\pm}0.1g$) to apparent satiation for 8 weeks. The results showed that growth performance in terms of weight gain (WG) and specific growth rate (SGR) increased with increasing dietary protein level from 35 to 55% at the same dietary lipid level. At the same dietary lipid content, WG and SGR obtained with diets containing 55% protein was significantly higher than those obtained with diets containing 45 and 35% protein. No significant effect on growth rate was found when the dietary level of lipid was increased from 7 to 14%. While the levels of protein and lipid in the diets had no significant effect on feed intake, other nutrient utilization efficiency parameters including daily protein intake (DPI), feed efficiency (FE), and protein efficiency ratio (PER) showed a similar trend to that of growth rates, with the highest values obtained with diets containing 55% protein. Muscle chemical composition was not significantly affected by the different dietary treatments for each dietary lipid or protein level tested. These findings may suggest that a practical diet containing 55% protein and 7% lipid provides sufficient nutrient and energy to support the acceptable growth rates and nutrient utilization of mandarin fish juveniles.

• Journal of Ecology and Environment
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• v.34 no.3
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• pp.251-257
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• 2011

The purpose of this study was to investigate the acclimation responses of Tamarix chinensis to cold stress. We evaluated the acclimation responses by measuring biomass, daily elongation rate, chlorophyll content, and total soluble carbohydrate content. The plant samples comprised leaves from seedlings of 2 different ages (8 and 12 weeks); the leaves were collected 0, 2, and 4 weeks after cold treatment. We found that the cold-treated samples showed reduced daily elongation rates and chlorophyll content. Further, these samples showed more than 8-fold increase in the total soluble carbohydrate content. However, the seedling ages did not have a significant influence on the growth of cold-treated seedlings. On the basis of these findings, we can conclude that T. chinensis seedlings aged less than 1 year old show acclimation to cold stress by accumulating soluble carbohydrates. This study may help us understand how T. chinensis seedlings acclimatize to their first cold season.

• Journal of Aquaculture
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• v.20 no.3
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• pp.194-198
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• 2007

Reproductive traits of Palaemon gravieri such as embryo size, number of embryo (fecundity), incubation period, larval development mode, larval development period, larval survival and larval growth were described and compared to analyze the correlation among those traits. Embryo volume is a primary factor determining other ensuing reproductive features. Egg volume was $0.042mm^3$ in the first developmental stage. Embryo volume in P. gravieri was comparatively small which is indicative of great number of embryo (y = 3.0161x + 0.0185 $R^2$ = 0.74 positive isometric relationship) and relatively long incubation period. Larvae survived from zoea 1 to post-larvae and it took 45 days at $22^{\circ}C$. Survival rate of the larvae was rather great in the early stage and thereafter steadily decreased. Daily growth rate of larvae in P. gravieri at $22^{\circ}C$ was 0.0195 mm on average. They grew steadily as time went by. Incubation period was between 10-14 days at $22^{\circ}C$. Larval development mode was almost complete planktotrophic. PNR (point of no return) appeared to be the third day on average. Survival rate of larvae without feeding declined rapidly between 3 and 4 days. Larval development period and stage frequency were 23-30 days and 11 stages which imply prolonged larval period and high mortality. The pattern of brood production followed fast successive parturial pattern. Most ovigerous female had mature ovary when they performed parturial molt soon after hatching (larval release).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.671-676
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• 2011

To determine the optimum light intensity for mass culture of the brackish-water cyclopoid copepod Paracyclopina nana, survival, growth, and productivity of the copepod were examined at several light intensities (0, 10, 100, 500, 1,000 lx). The survival rate of P. nana from nauplius to adult decreased with increasing light intensity. The highest survival rate was found under the dark condition, with 61.7% surviving; no significant difference was observed between 0 and 10 lx (51.7%) and the lowest survival rate was with 100 lx (26.7%). Survival rates at 500 and 1,000 lx were significantly lower in comparison with other conditions. The developmental period from nauplius to copepodid (5.8 days) and to adult (11.8 days) at 10 lx was significantly shorter than in the other treatments. Daily mean nauplius production of adult females over 7 days at 0, 10 and 100 lx was significantly higher than at 500 and 1,000 lx. In the 1,000 lx treatment, 99% of the adult females died on the $14^{th}$ day. The optimum light intensity for the mass culture of P. nana could be 10 lx, which had no adverse effects on survival, development, or reproduction.

• Journal of Life Science
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• v.8 no.3
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• pp.272-278
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• 1998

To investigate the effects of different UV-B levels on plant growth, cucumber plants were subjected to three levels of biologically effective ultraviolet-B(UV--$B^{BE}$ radiation [daily dose : 0.03(No UV-B), 6.40(Low UV-B) and 11.30 (High UV-B) kJ $m^{-2}$, UV--$B^{BE}$] in the growth chambers for 3 weeks during the early growth period. High and low levels of UV-B irradiation drastically decreased both dry weight and leaf area, but increased specific leaf weight of cucumber. Plants subjected to UV-B resulted in 30% and 20% reduction of photosynthesis rate by high and low UV-B, respectively. However, respiration rate was not affected by the UV-B. With increasing UV-B intensity, total chlorophyll contents were decreased linearly, while the contents of flavonoid were increased linearly. These results suggest that the present levels of UV-B may affect the growth of cucumber plant compared with a UV-B-free condition. It is likely that the growth of cucumber will be affected by enhanced UV-B due to ozone depletion in the near future.