scholarly journals Effects of copper microparticles on the growth and survival of juvenile rainbow trout (Oncorhynchus mykiss Wal.)

2021 ◽  
Vol 66 (4) ◽  
pp. 359-369
Author(s):  
Nebojsa Savic ◽  
Radoslav Dekic

During the farming of juvenile rainbow trout (Oncorhynchus mykiss), losses can be very high. In aquaculture, various agents are used, such as copper, for the purpose of preventive action and prevention of the appearance of pathogens (ectoparasites, etc.). The aim of this study was to determine the effects of substrate-fixed copper microparticles on the growth and survival of juvenile rainbow trout (Oncorhynchus mykiss) up to the age of 5 months. The experiment was conducted in the Laboratory for Aquaculture of the Faculty of Agriculture, University of Banja Luka, for 142 days in flow aquariums with a 65 l/aquarium volume. The experiment was set up in two groups (150 units/group) with three replicates (50 units/replicate), a control group without copper microparticles (K) and a group with copper microparticles (Cu). The initial weight and total body length (mean ? SD) of rainbow trout in group K were 0.199 ? 0.008 g and 2.876 ? 0.036 cm, and in group Cu 0.197 ? 0.009 g and 2.893 ? 0.038 cm. The average total length and body weight of individuals from the K and Cu groups were similar (p > 0.05). The differences in FCR, CF, SGR and TGC between group K and group Cu were not statistically significant (p > 0.05). Survival of juvenile rainbow trout was high and it was 97.33% in group K and 96.00% in group Cu, and no statistically significant difference was found (p > 0.05). The growth and survival of juvenile rainbow trout in the K and Cu groups were similar.

2013 ◽  
Vol 58 (3) ◽  
pp. 185-193
Author(s):  
Nebojsa Savic ◽  
Milanka Drinic ◽  
Bozo Vazic ◽  
Biljana Rogic

This paper presents the results of the effects of different sizes of meals (80%, 90%, 100%, 110% and 120% regarding the amount recommended by the food producer) on the growth characteristics of young rainbow trout (Oncorhynchus mykiss Wal.) aged from 2 to 3.5 months. The experiment was carried out at the Laboratory of Aquaculture, Faculty of Agriculture, University of Banja Luka for a period of 47 days. In the experiment, there were a total of 500 fish, divided into five groups, and placed in the 55-l aquarium with a constant flow of water and the aeration system. The main parameters of water quality were analyzed every day and they included: water temperature 12.64-12.76?C, content of dissolved oxygen 7.83-8.09 mg/l, saturation of water with oxygen 75.47-77.39% and pH value 7.224-7.268. In the end, the average individual weight and body length (?standard deviation) of young rainbow trout, regarding the experimental groups (EG), were reached: EG80 10.53?2.58 g and 9.94?0.76 cm, EG90 12.14?2.97 g and 10.45?0.86 cm, EG100 13.18?2.91 g and 10.67?0.82 cm, EG110 13.80?3.14 g and 10.82?0.78 cm, EG120 14.58?3.63 g and 10.81?1.11 cm. Statistically highly significant differences were found between the means of experimental groups (p <0,01). The coefficient of condition of young rainbow trout at the end of the experiment was similar in the treatments EG80, EG90, EG100 and EG110 (1.06 to 1.09), and it was the highest in the treatment EG120 (1,15?0,17). Generally, it can be said that increasing of the size of meals up to 10% above the recommended value does not cause significant differences, and if the increase is greater than 10%, statistically significant difference in body weight occurs.


Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2117
Author(s):  
Seyed Hossein Hoseinifar ◽  
Ghasem Rashidian ◽  
Hamed Ghafarifarsani ◽  
Mohammad Amin Jahazi ◽  
Mehdi Soltani ◽  
...  

Pectins are a group of carbohydrates found in structural parts of terrestrial plants with wide industrial and biomedical applications. This study was designed to investigate the dietary effects of apple pomace-derived pectin (APDP) in rainbow trout (Oncorhynchus mykiss). Four formulated diets were provided with different inclusion levels of APDP for 30 days: 0, 5, 10, and 20 g kg−1; referred to as control, P1, P2, and P3, respectively. In this study, 300 fish (3.56 ± 0.007 g) were randomly distributed into twelve fiberglass tanks and fed 3% of their respective body weight four times a day. At the end of the experiment, growth parameters, including weight gain, specific growth rate, and food conversion ratio (FCR) were significantly improved in P1 and P2 treatments compared to those of the other treatments. Results from proximate composition analysis showed that protein content increased, and lipid decreased in the P2 and P3 groups. Serum lysozyme, complement activity, total immunoglobulin levels, and total protein were significantly enhanced in all treatments compared to those of the control group. Gene expression results showed no significant difference in regulation of interleukin-1β (IL-1β); however, up-regulation of lysozyme, interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) was observed in both P1 and P2. Unlike lipase, the activity of protease and amylase significantly increased in fish receiving different levels of APDP compared to the control (p < 0.05). In conclusion, the present findings suggest APDA as a promising feed additive for rainbow trout.


2021 ◽  
Author(s):  
Mohammad Hossein Khanjani ◽  
Gholamreza Ghaedi ◽  
Moslem Sharifinia

Abstract This study aimed to investigate the effect of beta-glucan in rainbow trout’s diet on survival, growth performance, hematological, immunity and biochemical parameters. Rainbow trout (Oncorhynchus mykiss) with an average weight of 6.35 ± 0.09 were stocked in 30 fiberglass tanks with a volume of 200 liters. Four treatments including: control group (0%), 0.5, 1 and 2% of beta-glucan were considered for 8 weeks. The results showed that the survival and growth performance of rainbow trout in the control group were at the lowest level and showed a significant difference with other treatments. The highest percentage of hematocrit (47.9%), white blood cell count, neutrophil percentage (35.2%) was observed in the treatment with 2% beta-glucan. Also, the highest lysosomal activity (59.7 units’ mL− 1, IgM (54.7 mg dL− 1), C3 and C4 was obtained in 2% beta-glucan treatment. Biochemical parameters showed improvement in treatments fed with 1 and 2% beta-glucan. In general, the present study showed that 2% beta-glucan in the diet of rainbow trout improves growth performance, survival, hematological, immunity and biochemical parameters.


Animals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 187 ◽  
Author(s):  
Paulo Rema ◽  
Subramanian Saravanan ◽  
Benjamin Armenjon ◽  
Constant Motte ◽  
Jorge Dias

Insects are emerging as a sustainable alternative to fishmeal and fish oil in aquafeeds. This study assessed the effect of graded incorporation levels of defatted yellow mealworm (Tenebrio molitor) protein meal on juvenile rainbow trout (Oncorhynchus mykiss) growth performance, body composition, and apparent nutrient digestibility. The trial comprised five dietary treatments: control diet with 25% fishmeal, and four experimental diets with yellow mealworm protein meal at 5%, 7.5%, 15%, or 25%, which corresponded to a fishmeal replacement of 20%, 30%, 60%, or 100%, respectively. After 90 days, the graded incorporation of insect protein meal led to a significant stepwise increase in final body weight, and a significant improvement of specific growth rate, feed conversion ratio, and protein efficiency ratio compared to the control treatment. Regardless of the incorporation level, the insect protein meal had no effects on fish whole-body composition and apparent digestibility coefficients of dry matter, protein, fat, phosphorus, and energy. Protein, phosphorus, and energy retention significantly increased in fish fed the diets with an insect protein meal. In conclusion, the yellow mealworm protein meal could effectively replace 100% of fishmeal in the diet of juvenile rainbow trout with positive effects on its overall zootechnical performance.


1993 ◽  
Vol 50 (10) ◽  
pp. 2119-2128 ◽  
Author(s):  
Michael D. Riehle ◽  
J. S. Griffith

We assessed changes in density, distribution, and microhabitat of age-0 rainbow trout (Oncorhynchus mykiss) in Silver Creek, a partially spring-fed stream, by periodic snorkeling in August 1987 through January 1988. We examined trout stomach contents and invertebrate drift samples in diel collections in August, September, October, and January to test if the period of feeding shifted from daytime to nighttime, concurrent with a transition to day concealment. In late September, fish aggregated briefly during the day and then began to conceal themselves in macrophyte beds, undercut banks, and submerged sedges and grasses along streambanks as temperature dropped below 8 °C in early October. Fish emerged from concealment at night, and numbers of trout visible were greatest 30–60 min after sunset and about 30 min before sunrise. Periods of peak feeding changed from afternoon and evening in August and September, when fish were day active, to mainly at night in October after the initiation of day concealment. Trout did not feed upon abundant chironomids in the daytime drift in October. In January, fish fed at 1–4 °C on mayflies, and stomachs were fullest in the early morning. Observations suggest that Silver Creek trout experienced a metabolic deficit that began in September.


2021 ◽  
Vol 221 ◽  
pp. 112454
Author(s):  
Mahaut Beghin ◽  
Mélodie Schmitz ◽  
Stéphane Betoulle ◽  
Olivier Palluel ◽  
Sébastien Baekelandt ◽  
...  

Chemosphere ◽  
2017 ◽  
Vol 188 ◽  
pp. 548-556 ◽  
Author(s):  
Gillian McEneff ◽  
Brian Quinn ◽  
Matthew Bennion ◽  
Sorcha Dolan ◽  
Kathleen O'Rourke ◽  
...  

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