• Fisheries and Aquatic Sciences
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• v.11 no.3
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• pp.125-132
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• 2008

The development of a fish that functionally provides both antioxidant and fat-reducing effects is an important goal in nutrition and aquaculture research. Dietary conjugated linoleic acid(CLA) can be successfully incorporated in fish muscle and viscera, but CLA and carotenoids have not been evaluated in such fish. An 8 weeks growth trial was conducted using rainbow trout, and all fish were fed twice daily with experimental diets containing graded amounts of CLA(1% and 5%). At the end of the experiment, the daily growth index, feed conversion rate, lipid class, and fatty acid composition were determined. Dietary CLA did not enhance the growth parameters of rainbow trout but did improve the feed conversion rate. The muscular polar lipid content decreased during the feeding period, while the content was stable in the viscera. In addition, a diet high in CLA decreased the polyunsaturated fatty acid content, but had no effect on the content of monounsaturated and saturated fatty acid in muscle.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.5
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• pp.700-705
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• 2014

A 12-week feeding trial was conducted with 87 g rainbow trout to evaluate the effects on growth performances, feed efficiency and nutrient digestibility of adding ${\beta}$-mannanase and ${\alpha}$-galactosidase enzymes, solely or in combination. Seven diets were prepared by adding ${\beta}$-mannanase, ${\alpha}$-galactosidase and mixed enzyme at two different levels (1 g/kg and 2 g/kg) to control diet (without enzyme) including soybean meal. Mixed enzymes (1 g/kg, 2 g/kg) were prepared by adding ${\beta}$-mannanase and ${\alpha}$-galactosidase at the same doses (0.5+0.5 g/kg and 1+1 g/kg). At the end of the experiment, addition of ${\beta}$-mannanase, ${\alpha}$-galactosidase and mixed enzyme to diet containing 44% soybean meal had no significant effects on growth performance and gain:feed (p>0.05). In addition, adding ${\beta}$-mannanase, ${\alpha}$-galactosidase and mixed enzyme in different rations to trout diets had no affect on nutrient digestibility and body composition (p>0.05).

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1244-1247
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• 2007

Effects of muscle fluid concentrates from Styela clava on fish diets were investigated in rainbow trout(Oncorhynchus mykiss). Fish were fed on one of the isonitrogenous(48%) and isolipic(20%) feed containing 5 to 20% of muscle fluid concentrates for 8 weeks. Hematological parameters such as hemoglobin, hematocrit, albumin, glucose, total bililubin, triglyceride and glutamic pyruvate transaminase of the rainbow trout which were fed on the diets varied, but no specific trend became apparent. However, glutamic oxaloacetic transaminase value was significantly higher than that of normal fishes. Therefore, concentrated ascidian fluid which is normally discarded, can be combined with commercial diets for the normal growth of rainbow trout.

• Journal of Aquaculture
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• v.12 no.4
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• pp.293-301
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• 1999

This study was conducted to evaluate the possible utilization of 5 different animal protein sources in juvenile rainbow trout, Oncorhynchus mykiss. Meat and bone meal (MBM), feather meal (FM), squid liver powder (SLP), poultry by-product(PBP) and blood meal (BM) were chosen to be the candidate for the possible ingredients for the dietary fish meal replacer in rainbow trout feed. Six different diets were formulated of isonitrogenous and isocaloric basis of $48\textperthousand$ crude protein and 16.7 kJ/g diet: diet 1, $100\textperthousand$ white fish meal (WFM); diet w, $80\textperthousand$ WFM +20% MBM; diet 3, 80% WFM +20% FM; diet 4, 80% WFM+20% SLP; diet 5, 80% SFM+20% PBP; diet 6, 80% WFM +20% BM. As the dietary protein sources, each diet containing 34.7% of animal protein were supplied by WFM with and without MBM, FM, SLP, PBP or BM and approximately 64.2% of plant protein. After one week of conditioning period, fish averaging 2g were divided into six groups and fed one of the experimental diets for 8 weeks. After eight weeks of feeding trials, there were no significant differences in weight gain and feed conversion ratio among groups of fish fed diet 1, 3, 4, 5 and 6(P>0.05). However, weight gain of fish fed diet 2 were significantly lower than those of fish fed diet 1, 3, 4, 5 and 6(P<0.05). These results indicated that FM, SLP, PBP and BM can be used as a dietary fish meal replacer up to 20% in juvenile rainbow trout.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.330-336
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• 2016

Pollution caused by fecal solids released from recirculating aquaculture systems (RAS) is a growing global concern requiring immediate attention. Thus, this study investigated the physicochemical characteristics of fecal solid feed from RASs used for eel and rainbow trout farming. The concentrations of proteins, lipids, crude ash, and moisture in eel fecal solids were 10.9%, 1.2%, 85.8%, and 72.2%, respectively, while those in rainbow trout fecal solid feed were 20.5%, 3.2%, 70.9%, and 87.0%, respectively. The control group was fed a mixture of sea cucumber and dried sea mud. The protein digestibilities of eel and rainbow trout fecal solids were 25.43% and 23.96%, respectively, while the respective lipid digestibilities were 35.62% and 36.80%, respectively.

• Fisheries and Aquatic Sciences
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• v.22 no.1
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• pp.1.1-1.8
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• 2019

Five experimental diets were formulated to evaluate the effects of dietary enzymatically hydrolyzed tuna by-product on growth, non-specific immune responses, and hematology of juvenile rainbow trout (Oncorhynchus mykiss). A basal diet with 50% of fishmeal was used as control (CON) and four other diets replaced 12.5% ($TBB_{12.5}$), 25% ($TBB_{25}$), 37.5% ($TBB_{37.5}$), and 50% ($TBB_{50}$) of fish meal in the CON diet. Juvenile rainbow trout ($4.87{\pm}0.05g$) were randomly distributed into 15 tanks (50 L) and fed 3-4% of wet body weight two times a day. At the end of 7 weeks of feeding trial, weight gain, specific growth rate, feed efficiency, and protein efficiency ratio of fish fed CON diet were significantly higher than those of fish fed $TB_{50}$ diet (P < 0.05). But there were no significant differences among fish fed CON, $TBB_{12.5}$, $TBB_{25}$, and $TBB_{37.5}$ diets (P > 0.05). There were no significant differences in GPT levels among fish fed CON, $TBB_{12.5}$, $TBB_{25}$, and $TBB_{37.5}$ diets. Also, there were no significant differences in lysozyme, superoxide dismutase, glucose, and total protein levels in all experimental diet (P > 0.05). The broken-line analysis indicated that the minimum dietary level of enzymatically hydrolyzed tuna by-product to replace fishmeal could be 29.7% in rainbow trout. These results indicated that the optimum level of dietary enzymatically hydrolyzed tuna by-product could replace greater than 29.7% but less than 37.5% of fishmeal in juvenile rainbow trout diet.

• Fisheries and Aquatic Sciences
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• v.21 no.11
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• pp.32.1-32.7
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• 2018

Trout production is a growing activity in recent years but requires new alternative sources of feed to be sustainable over time. The objective of this research was to determine the apparent digestibility coefficient (ADC) of dry matter (DM), organic matter (OM), crude protein (CP) and digestible energy (DE) of $ka{\tilde{n}}iwa$ (Chenopodium pallidicaule Aellen), kiwicha (Amaranthus caudatus L), quinoa (Chenopodium quinoa Willd), beans (Phaseolus vulgaris L.), sacha inchi, (Plukenetia volubilis L) and jumbo squid (Dosidicus gigas) meal in juvenile rainbow trout. The experimental diets were composed of a 70% basal diet and 30% of any raw materials. The ADC was determined by the indirect method using insoluble ash as a non-digestible marker. Jumbo squid, sacha inchi and quinoa showed the highest values of ADC (%) of DM (84.5, 73.5 and 69.7), OM (89.1, 78.4 and 72.9), CP (93.2, 98.0 and 90.3), and DE (4.57, 4.15 and 2.95 Mcal/kg DM), respectively. The ADC values for $ka{\tilde{n}}iwa$, kiwicha and bean were significantly lower. In conclusion, quinoa meal and jumbo squid meal have an acceptable digestibility but sacha inchi meal is a potential alternative for rainbow trout feeding in the future.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.3
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• pp.231-242
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• 1990

A study is reported which investigated the additive nature of digestible energy (DE) from dietary nutrients and to estimate the relative energy values of different energy-yielding nutrients in practical trout diets. A growth study was conducted over 12 weeks with 6 diets. Rainbow trout (Oncorhynchus mykiss) were fed diets once a day ad libitum. Digestible energy values determined and calculated had direct relationship indicating additive nature of such values for feed ingredients. Overall growth performance was best in a diet containing 33% digestible protein (DP) with a DP/DE ratio of 18.6. A reduction in digestible protein level with the same DP/DE rat io led to a significant decrease in growth and feed efficiency. The increase of 7% of lipid with concomitant decrease in protein resulted in the relative gain of 130% in growth and nutrient retention, suggesting that 1 g of lipid is equal to about 1.3 g of proteins in terms of net energetic value. Replacement of 10% of dietary lipid by carbohydrates led to a slight decrease in energy retention efficiency but to a great increase in lipid retention efficiency (130%) showing that dietary carbohydrates led to increased lipogenesis.

• Food Science of Animal Resources
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• v.44 no.4
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• pp.805-816
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• 2024

The aim of this study was to evaluate a new Bacillus amyloliquefaciens B-1895 probiotic as a feed additive for farmed trout. Final weight, absolute and average daily gain of fish, and average daily growth rate were higher in the group that received the probiotic than in the control group (p<0.05). Moreover, the probiotic-fed trout had more intense growth rates than the control group (higher by 15.7%; p<0.05). A decrease in feed ratio was also observed in the group that received probiotic (25% decrease; p<0.05), indicating more efficient digestion and assimilation of feed. In general, the introduction of probiotic in the feed did not adversely affect the functional status of the fish. In young trout of the control group, when assessing the general chemical composition of the organism in the muscle tissue revealed significantly (p≤0.001) higher level of moisture content by 5.1% and lower by 11.0% dry matter content. In muscle, the protein content was higher by 1.33% (p≤0.001) and fat content by 2.1% (p≤0.001) in experimental fish. Generally, Lactobacilli, Enterococcus, Vibrio, Bacillus, and coliform bacteria were found in the intestinal samples of rainbow trout. Significant reliable difference (p≤0.05) between the samples of experimental and control groups was noted in the content of Bacillus bacteria. In the control group, 5.0±0.4×10³ CFU/g was detected, while in the experimental group 8.4±0.8×10⁴ CFU/g. Overall, the data indicate that probiotic bacteria B. amyloliquefaciens B-1895 has no adverse effect on selected microorganisms in the study fish.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.4
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• pp.551-558
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• 2015

This study was carried out to evaluate the dietary threonine requirement by measuring the plasma free threonine and ammonia concentrations in rainbow trout, Oncorhynchus mykiss after dorsal aorta cannulation. A total of 70 fish (average initial weight $506{\pm}8.2g$) were randomly distributed into each of the 14 net cages (5 fish/cage). After 48 hours (h) of feed deprivation, each group was intubated at 1% body weight with one of the seven L-amino acid based diets containing graded levels of threonine (0.42%, 0.72%, 0.92%, 1.12%, 1.32%, 1.52%, or 1.82% of diet, dry matter basis). Blood samples were taken at 0, 5, and 24 h after intubation. Post-prandial plasma free threonine concentrations (PPthr) of fish 5 h after intubation with diets containing 1.32% or more threonine were significantly higher than those of fish intubated with diets containing 1.12% or less threonine (p<0.05). Post-absorptive free threonine concentrations (PAthr) after 24 h of intubation of the fish with diets containing 0.92% or more threonine were significantly higher than those of fish intubated with diets containing 0.72% or less threonine. Post-prandial plasma ammonia concentrations (PPA, 5 h after intubation) were not significantly different among fish intubated with diets containing 1.12% or less threonine, except the PPA of fish intubated with diet containing 0.42% threonine. Broken-line model analyses of PPthr, PAthr, and PPA indicated that the dietary threonine requirement of rainbow trout should be between 0.95% (2.71) and 1.07% (3.06) of diet (% of dietary protein on a dry matter basis).