• Journal of Aquaculture
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• v.19 no.4
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• pp.299-304
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• 2006

This study was conducted to investigate the effects of protein and lipid levels of extruded pellet on growth and body composition of juvenile flounder. Six extruded dry pellets were formulated to contain two protein levels (50 and 55%) and three lipid levels (8, 12 and 15%). Triplicate groups of fish (initial mean weight 21 g) were hand-fed to apparent satiation two times a day for 9 weeks. Survival, weight gain and daily feed intake were not significantly affected by dietary protein and lipid levels. Feed efficiency and protein efficiency ratio were significantly (P<0.001) affected by dietary lipid level, and tended to increase as dietary lipid level increased. Feed efficiency ratio of fish fed the 55% protein diet with 15% lipid was not significantly different from that of fish fed the 50% protein diet with 15% lipid, but significantly (P<0.05) higher than that of fish fed the other diets. Protein efficiency ratio of fish fed the 55% protein diet with 15% lipid was significantly (P<0.05) higher than that of fish fed the 50% protein diet with 8% lipid and 55% protein diets with $8{\sim}12%$ lipids. The contents of moisture, crude protein and lipid in the liver was significantly (P<0.01) affected by dietary lipid level. The results of this study indicate that an increase in lipid level at 50-55% protein in extruded pellet can improve feed efficiency for juvenile flounder.

• Journal of Aquaculture
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• v.5 no.1
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• pp.9-17
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• 1992

To test the availability of soybean meal as a protein source and to increase its effectiveness in the diets for the fingerlings of red seabream, some feeding trials were conducted. Two different types of diet, steam pellet and soft dry pellet, contained various levels of soybean meal, were used. The growth, feed efficiencies, and body compositions were examined after the feeding trials. Results of the experiments suggested that dietary protein level could be reduced from $52{\%}$ to $47{\%}$ by elevating dietary energy level from $13{\%}$ to $21{\%}$ with lipid. The best results of growth and feed efficiencies were achieved by the diet that containing $47{\%}$ of crude protein and $20{\%}$ of crude lipids. The growths and feed efficiencies showed no difference when $20{\%}$ of fish meal in the experimental diet were substituted by soybean meal. Therefore, $20{\%}$ of fish meal could be substituted by soybean meal without reducing growth rates or feed efficiencies of fingerling red sea bream.

• Animal Bioscience
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• v.36 no.10
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• pp.1584-1595
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• 2023

Objective: This study was conducted to evaluate the effect of a low-protein diet on growth performance, carcass traits, nutrient digestibility, blood profiles, and odor emissions in growing-finishing pigs. Methods: A total of 126 crossbred pigs ([Yorkshire×Landrace]×Duroc) with an average body weight (BW) of 38.56±0.53 kg were used for a 14-week feeding trial. Experimental pigs were allotted to one of 6 treatments in 3 replicates of 7 pigs per pen in a randomized complete block design. Pigs were fed each treatment diet with different levels of crude protein (CP). Phase 1 (early growing): 14%, 15%, 16%, 17%, 18%, 19%; phase 2 (late growing): 13%, 14%, 15%, 16%, 17%, 18%; phase 3 (early finishing): 12%, 13%, 14%, 15%, 16%, 17%; phase 4 (late finishing): 11%, 12%, 13%, 14%, 15%, 16%. All experimental diets in each phase were contained the same concentration of lysine (Lys), methionine (Met), threonine (Thr), and tryptophan (Trp). Results: Over the entire experimental period, there was no significant difference in BW, average daily feed intake, and gain-to-feed ratio among all treatments (p>0.05), but a quadratic effect (p = 0.04) was observed in average daily gain (ADG) during the late finishing phase with higher ADG in Group D. Blood urea nitrogen concentration linearly increased with an increase in dietary CP levels (p<0.01). Regarding nutrient digestibility, excreted nitrogen in urine and feces and nitrogen retention linearly increased as the CP level increased (p<0.01). A linear effect was observed with increasing CP levels in amines, ammonia, and hydrogen sulfide in odor emissions (p<0.01). No significant effects were observed in the measurements of carcass traits and meat characteristics (p>0.05). Conclusion: In phase feeding, reducing the CP level to 14% in early-growing pigs, 13% in late-growing pigs, 12% in early-finishing pigs, and 11% in late-finishing pigs is recommended.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.469-474
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• 2000

This study was conducted to investigate the utilization of defatted soybean meal as a substitute for fish meal in the diet for juvenile flounder (Paralichthys olivaceus). Duplicate groups of average weighing 35 g were fed one of four isonitrogenous ($54{\%}$) and isocaloric (575 kcal/100 g diet) diets containing $0{\%}, 10{\%}, 20{\%} and 30{\%}$ soybean meal for 45 days. Survival rates of all groups were $100{\%}$, Weight gain of fish decreased with increasing dietary soybean meal levels, However, this value was not significantly different between fish fed the control and $10{\%}$ soybean meal diet (P > 0.05). Feed efficiency and protein efficiency ratio decreased with increasing dietary soybean meal levels, but no significant differences were found among fish fed the control, $10{\%}\;and\;20{\%}$ soybean meal diets (P > 0.05). Daily feed and protein intake increased with increasing dietary soybean meal level. Crude protein and moisture content of liver tended to decrease and crude lipid content tended to increase with decreasing of dietary soybean meal levels. Plasma total cholesterol levels of fish fed the diets containing $20{\%}\;and\;30{\%}$ soybean meal were significantly lower than that of fish fed control diet (P < 0.05), Plasma GOT level significantly increased with increasing dietary soybean meal level (P < 0.05). It is concluded that soybean meal can be used as a partial substitute for fish meal up to $10{\%}$ in this dietary formulation for growth of juvenile flounder.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.10
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• pp.1399-1406
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• 2000

A continuous culture study was conducted to determine the impact of ruminal degradable soy protein (S-RDP) level and dilution rate (D) on growth of ruminal non-structural carbohydrate-fermenting microbes. Corn starch, urea and isolated soy protein (ISP) were used to formulate three diets with S-RDP levels of 0, 35 and 70% of total dietary CP. Two Ds were 0.03 and $0.06h^{-1}$ of the fermenter volume in a single-effluent continuous culture system. As S-RDP levels increased, digestibilities of dietary dry matter (DM), organic matter (OM) and crude protein (CP) linearly (p=0.001) decreased, whereas digestion of dietary starch linearly (p=0.001) increased. Increasing D from 0.03 to $0.06h^{-1}$ resulted in decreased digestibilities of dietary DM and OM, but had no effect on digestibilities of dietary starch (p=0.77) and CP (p=0.103). Fermenter pH, the concentration of volatile fatty acids (VFA) and daily VFA production were unaffected (p=0.159-0.517) by S-RDP levels. Molar percentages of acetate, propionate and butyrate were greatly affected by S-RDP levels (p=0.016-0.091), but unaffected by D (p=0.331-0.442). With increasing S-RDP levels and D, daily bacterial counts, daily microbial N production (DMNP) and microbial efficiency (MOEFF; grams of microbial N produced per kilogram of OM truly digested) were enhanced (p=0.001). The increased microbial efficiency with increasing S-RDP levels is probably the result of peptides or amino acids that served as a stimulus for optimal protein synthesis. The quantity of ruminal degradable protein from soy proteins required for optimum protein synthesis of non-structural carbohydrate-fermenting microbes appears to be equivalent to 9.5% of dietary fermented OM.

• Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.104-110
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• 2009

Feeding trials were performed at two different water temperatures (summer and winter seasons) to identify suitable protein and lipid (energy) levels to be used in formulating extruded pellets for olive flounder. Experiments were conducted to determine the effects of protein and lipid levels in extruded pellets on the growth and body composition of the flounder in both feeding trials. Six experimental diets were prepared containing three protein levels (46%, 51%, and 56%) and two lipid levels (10% and 17%). In the first experiment, during the summer season ($22{\pm}2.2^{\circ}C$), a triplicate group of fish (initial weight, 114 g) were fed to satiation one of the six diets for 11 weeks. The highest weight gain was observed in fish fed the 56/17 (% protein/% lipid) diet, but this weight gain was not significantly different from that of fish fed the other diets, except for those fed the 46/10 diet. The feed efficiency and protein efficiency ratio of fish fed the 17% lipid diets were higher than those of fish fed the 10% lipid diets at each protein level. In the second experiment, during the winter season ($13{\pm}1.5^{\circ}C$), a triplicate group of fish (initial weight, 107 g) were fed to satiation one of the six diets for 9 weeks. Weight gain was not significantly different among all groups. The feed efficiency and protein efficiency ratio tended to increase with increasing dietary lipid level at each protein level. The whole-body crude lipid content of the of fish fed the 17% lipid diets was significantly higher than that of fish fed the 10% lipid diets at each protein level in both feeding trials. Based on the data obtained in this study, the inclusion of dietary protein at a level of 46% appears to be sufficient to support optimal growth, and increasing the dietary lipid level from 10% to 17% had no beneficial effects on the growth and feed utilization of olive flounder (110-300 g), except for fish fed a 56% protein diet in the summer season.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.4
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• pp.516-523
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• 2010

This study was conducted to investigate the physicochemical and sensory characteristics of tofu prepared with the addition of lotus root powder (LRP). The moisture, crude ash, carbohydrate, crude protein, and crude lipid contents of the lotus root powder were 8.29%, 4.73%, 30.66%, 47.84%, and 8.48%, respectively. The yield rate of the tofu did not differ significantly according to the level of added LRP; however, there was a significant decrease in pH and a significant increase in acidity. The L and b values of the tofu decreased as the amount of LRP in the formulation increased, whereas the a value increased. Furthermore, hardness and cohesiveness increased significantly as the level of LRP increased. In sensory evaluation, LRP tofu had low scores in air cell size and a beany smell, but high scores in hardness. In terms of overall acceptability, the preferred tofu samples were the control and that containing 0.3% lotus root powder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.4
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• pp.209-214
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• 1974

The utilization dietary protein in young rainbow trout was investigated when feeded with the diets of controlled levels of casein and lipids for 12 days. The composition of the diet is shown in Table 1. Body weight gain was in proportion to the protein content in diet up to $40\%$, ana the maximum was obtained with $40.4\%$ of crude protein (Fig. 1, Table 2). On the other hand, the accumulated protein in body also showed almost maximum value around 40n of protein level in the diet and: the change of accumulated protein showed a little with more-protein level(Fig. 3, Table 9). The protein accumulation rate (protein accumulated/protein consumed) showed its highest value at about $40\%$ of protein level, while the protein utilization value (protein accumulation rate x protein content of diet) attained its highest value at $54.8\%$ of protein level (Table 3). With the above results it is observed that the requirement of dietary protein for young rainbow trout is about $40\%$ of protein in the diet when casein is used as the sole protein source. In protein efficiency ratio (PER) the lower protein level in the diet, the higher PER yields and the more the quantity of protein increases, the more PER decreases and its relation could be figured out as an equation of y=4.91-0.034x (Fig.4), Nose measured PER utilizing the diet which result of this, it is reported that PER rate of casein dropped within the extent of $25\%$ protein in diet. The reason why such a different PER rate appeared at the low protein level is revealed as the carbohydrate is low but the lipid high in capacity of utililzing nutrients for rainbow trout. The relation between the protein content of diet and the conversion factor, feed efficiency were determined and the results are shown in Fig. 2.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1588-1596
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• 2006

An experiment was conducted to study the effect of different dietary protein levels on the performance, nutrient balances, blood biochemical parameters and thyroid hormones of crossbred calves. Thirty crossbred (Bos taurus${\times}$Bos indicus) calves aged 3-5 months were divided into 3 equal groups of 10 each and fed graded levels of crude protein, namely 100 (NP), 75 (LP) and 125 (HP) percent of the Kearl recommendations for 105 d. The calves had access to ad libitum oat hay as the basal roughage. A metabolism trial of 6 d duration was conducted at 90 d of the study. Blood collection and its analysis for various hematological and biochemical parameters as well as thyroid hormones was done both during the pre- and post-experimental periods. The fortnightly body weight changes and the net gain did not differ significantly due to dietary variation. The average daily gain was $367{\pm}21.6$, $347{\pm}22.9$ and $337{\pm}26.4g$ in calves fed NP, LP and HP diets, respectively. Averaged across the feeding trial, oat hay intake was higher (p<0.05) in NP animals than HP or LP fed groups. The dry matter (DM) intake showed no significant difference between the 3 groups but the DM digestibility was higher (p<0.05) in the HP fed animals. The digestibility of crude protein, organic matter, crude fiber and nitrogen-free extract was significantly higher (p<0.05) on HP diets compared to LP or NP diets. The calves on all 3 diets were in positive nitrogen (N) balance, however the N retention was higher (p<0.05) in HP than in LP fed calves. The intake and retention of calcium and phosphorus were similar between the treatments. The blood biochemical profile revealed no significant influence of the dietary treatments on hemoglobin, packed cell volume as well as serum levels of glucose, total protein, albumin, globulin, Ca, P, and alkaline phosphatase. Serum levels of the circulating thyroid hormones ($T_3$ and $T_4$) tended to be lower (p>0.05) on feeding of the LP diet besides showing an increasing trend with the advancement of age. Considering the similar performance and metabolic profile, it could be concluded that crossbred calves can be satisfactorily reared on 25% lower protein level as recommended by Kearl for developing countries, which would not only economize the cost of production but also help to reduce environmental pollution attributable to livestock production.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1133-1139
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• 2009

This study was carried out to investigate effects of crude protein (CP) levels in total mixed rations (TMR) on growth performance and meat quality in growing Korean black goats. Thirty-six 6-month-old growing black male goats (initial body weight =17.95${\pm}$0.13 kg) were used. The goats were randomly divided into four treatments and 9 animals were allotted to each treatment. In terms of treatments, CP levels in TMR were 14, 16, 18, and 20% of dry matter (DM) and all diets were isocaloric (2.4 Mcal ME/kg DM). The experiment lasted for 20 weeks with a 15-day adaptation period. After the end of the trial, five goats from each treatment were slaughtered to measure carcass characteristics and meat quality. Average daily gain (ADG) significantly (p<0.05) increased as dietary CP levels increased, but the highest ADG was found on the 18% CP treatment. The higher CP levels in TMR significantly (p<0.05) decreased feed conversion ratio, but the lowest ratio was on the 18% CP treatment, suggesting a higher bioavailability of nutrients by balanced energy and protein levels on this treatment. There was no significant difference in dressing percentage among treatments, but there was a tendency for levels more than 16% CP in TMR to have a comparatively higher dressing percentage than the 14% treatment. The percentages of meat, fat and bone were not significantly influenced by dietary CP levels. Dietary CP levels did not influence chemical composition of goat meat. Furthermore, there was no significant difference among treatments in any of the sensory parameters except for tenderness. Tenderness was similar for 18 and 20% treatments, which were significantly (p<0.05) higher than the 14% treatment. The results from this study suggested that an adequate CP level in TMR for achieving optimal growth performance and meat quality of growing Korean black goats might be 18% of DM, and that dietary CP level above 18% seemed not to further increase growth performance and meat quality.