Apparent Digestibility in Rainbow Trout (Salmo Gairdneri): Influence of Hypoxia

1988 ◽  
Vol 45 (11) ◽  
pp. 2003-2009 ◽  
Author(s):  
T. Pouliot ◽  
J. de la Noüe
Keyword(s):  
Rainbow Trout ◽  
Feed Intake ◽  
Animal Protein ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Apparent Digestibility ◽  
Oxygen Saturation Level ◽  
Gross Energy ◽  
Isocaloric Diets ◽  
Different Sources

We assessed the influence of hypoxia, which is likely to reduce the productivity of fish culture, on the digestibility of nutrients in rainbow trout (Salmo gairdneri). Rainbow trout (seven to each diet) were kept for 8 d in water with an oxygen saturation level of 40.0 ± 4.0%, while control fish were kept in 89.4 ± 4.2% oxygen-saturated water. Three isonitrogenous and isocaloric diets composed of different sources of protein (animal, plant, and mixed) were used. The apparent digestibility coefficients (ADC) were calculated by the indirect method (chromic oxide) after the automatic collection of feces. The experimental hypoxia used did not change the ADC for protein (total nitrogen), gross energy, or dry matter. The amino acids only showed a tendency for better absorption: proline, glycine, alanine, and tryptophan had a significantly higher ADC (P < 0.05) in experimental fish than in control fish when the animal protein based diet was used. Finally, we noted that feed intake was diet dependent. In contrast with what we observed with the commercial (mixed protein sources) and plant protein based diets, the fish receiving the animal protein based diet maintained a normal (or returning to normal) feed intake when they were subjected to hypoxia.

Effect of animal and vegetal protein diets on feed intake and apparent digestibility of nutrients in rainbow trout (Oncorhynchus mykiss) infected by Aeromonas salmonicida, with and without chronic hypoxia stress

1998 ◽  
Vol 55 (9) ◽  
pp. 2019-2027 ◽  
Author(s):  
H Néji ◽  
J de la Noüe
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Feed Intake ◽  
Chronic Hypoxia ◽  
Phosphate Buffer Solution ◽  
Aeromonas Salmonicida ◽  
Animal Protein ◽  
Fish Feed ◽  
Apparent Digestibility ◽  
Rainbow Trout Oncorhynchus Mykiss

This study was undertaken to investigate the effects of bacterial infection (Aeromonas salmonicida) and chronic hypoxia on mortality, feed intake, and apparent digestibility of each of two diets in rainbow trout (Oncorhynchus mykiss). The diets were isonitrogenous (gross basis); one was based mainly on animal protein and the other on vegetal protein. In each of two separate and successive experiments, where the first served as a control for the second, fish were immersed on day 0 (d0) in either a sterile phosphate buffer solution (first experiment) or a suspension of A. salmonicida (second experiment). Thereafter, the fish were either exposed on d2 for 12 days to hypoxic conditions (60% of water oxygen saturation) or maintained under normal conditions. Feed intake was measured daily, while apparent digestibility coefficients for gross energy, dry matter, and crude protein were measured on d0, d2, d5, d9, d11, and d14. Among all infected fish, feed intakes were reduced (P < 0.05), regardless of the source of dietary protein or the degree of water oxygenation. Also, regardless of infection, the feed intakes of hypoxic fish that were fed the vegetal protein based diet were significantly less than those of fish that were fed the animal protein based diet. This response, however, was transitory, since normal levels of feed intake in the former fish were found by d3. The apparent digestibility coefficients for all parameters were unaltered by hypoxia (P > 0.05), but they were significantly reduced (P < 0.05) by A. salmonicida infection, especially during the critical period of infection (d5 and d9).

Apparent digestibility of protein, amino acids and gross energy in rainbow trout fed various feed ingredients with or without protease

Aquaculture ◽  
2020 ◽  
Vol 524 ◽  
pp. 735270 ◽  
Author(s):  
Seunghan Lee ◽  
M.A. Kabir Chowdhury ◽  
Ronald W. Hardy ◽  
Brian C. Small
Keyword(s):  
Amino Acids ◽  
Rainbow Trout ◽  
Apparent Digestibility ◽  
Feed Ingredients ◽  
Gross Energy ◽  
Protein Amino Acids

scholarly journals Downstream pH Changes in Water Flowing Over the Gills of Rainbow Trout

1986 ◽  
Vol 126 (1) ◽  
pp. 499-512 ◽  
Author(s):  
PATRICIA WRIGHT ◽  
TOM HEMING ◽  
DAVID RANDALL
Keyword(s):  
Rainbow Trout ◽  
Carbonic Anhydrase ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Stopped Flow ◽  
Water Acidification ◽  
Interlamellar Water ◽  
Water Ph ◽  
Ph Stat ◽  
Control Water

We investigated the pH of interlamellar water of trout (Salmo gairdneri) by following changes in the downstream pH of expired water using a stopped-flow method. As water flowed over the gills of control fish, there was a significant decrease in water pH. Acetazolamide added to the water increased the CO2 disequilibrium, while carbonic anhydrase (CA) eliminated the CO2 disequilibrium relative to control water. Mucus excreted by the fish was found to contain CA activity by the pH-stat technique. We conclude water acidification is due to the conversion of excreted CO2 to HCO3− and H+ at the gill surface.

Effect of a sprint-training protocol on acceleration performance in rainbow trout (Salmo gairdneri)

1991 ◽  
Vol 69 (3) ◽  
pp. 578-582 ◽  
Author(s):  
A. Kurt Gamperl ◽  
Dan L. Schnurr ◽  
E. Don Stevens
Keyword(s):  
Rainbow Trout ◽  
Maximum Velocity ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Sprint Training ◽  
Maximum Acceleration ◽  
Fast Start ◽  
Time Required ◽  
Two Stages ◽  
Training Protocol

Fast-start acceleration performance of rainbow trout (Salmo gairdneri) was measured after 9 weeks of sprint training (30°s duration, every 2nd day). Response latency and time required to complete the first two stages of a fast start were unaffected by the sprint-training protocol. Maximum acceleration (trained 1985 ± 176 (SE) cm/s2; control 1826 ± 144 cm/s2) and maximum velocity (trained 130 ± 7 cm/s; control 134 ± 14 cm/s) were also not significantly different following training. However, trained fish reached high rates of acceleration before control (untrained) fish. Thus, acceleration was higher in trained fish from 20 to 35 ms postshock. When fish are separated by start type, trained fish consistently had greater acceleration than control fish between 30 and 45 ms postshock. Alterations in fast-start performance due to sprint training may improve predator avoidance ability. Sprint training did not change critical swimming speed as measured using two separate protocols.

Increased Toxicity of Ammonia to Rainbow Trout (Salmo gairdneri) Resulting from Reduced Concentrations of Dissolved Oxygen

1981 ◽  
Vol 38 (8) ◽  
pp. 983-988 ◽  
Author(s):  
Robert V. Thurston ◽  
Glenn R. Phillips ◽  
Rosemarie C. Russo ◽  
Susan M. Hinkins
Keyword(s):  
Rainbow Trout ◽  
Dissolved Oxygen ◽  
Ammonia Toxicity ◽  
Control Fish ◽  
Toxicity Tests ◽  
Salmo Gairdneri ◽  
Median Lethal Concentration ◽  
Positive Linear Correlation ◽  
Acute Toxicity Tests ◽  
Flow Through

The median lethal concentration (LC50) of aqueous ammonia at reduced dissolved oxygen (D.O.) concentrations was tested in acute toxicity tests with rainbow trout (Salmo gairdneri) fingerlings. Fifteen 96-h flow-through tests were conducted over the D.O. range 2.6–8.6 mg/L, the former concentration being the lowest at which control fish survived. There was a positive linear correlation between LC50 (milligrams per litre un-ionized ammonia) and D.O. over the entire D.O. range tested; ammonia toxicity increased as D.O. decreased. Ammonia LC50 values were also computed for 12, 24, 48, and 72 h; the correlation with D.O. was greater the shorter the time period.Key words: ammonia toxicity, dissolved oxygen, rainbow trout, Salmo gairdneri

Effects of Exercise Training on the Performance, Growth, and Protein Turnover of Rainbow Trout (Salmo gairdneri)

1987 ◽  
Vol 44 (9) ◽  
pp. 1614-1621 ◽  
Author(s):  
D. F. Houlihan ◽  
P. Laurent
Keyword(s):  
Protein Synthesis ◽  
Rainbow Trout ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Degradation Rates ◽  
The Difference ◽  
Net Protein ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation ◽  
Better Than

Rainbow trout (Salmo gairdneri) that were made to swim continuously at 1 body length/s for 6 wk had double the growth rate of tank-rested control fish. The endurance to fatigue at a range of swimming velocities of these trained animals was significantly better than that of the controls. Measurement of the rate of protein synthesis in the tissues was carried out by the free pool flooding technique. Protein degradation rates were calculated from the difference between synthesis and net protein accretion. In controls and trained animals the fractional rates of protein synthesis and degradation were ranked gills > ventricle > red muscle > white muscle whereas the efficiencies of conversion of protein synthetised into protein retained as growth were in the reverse sequence. Synthesis rates in three of the four tissues of the trained animals were approximately double those of the control animals. Calculated degradation rates of proteins also increased in the trained animals; the increased growth rates resulted from the proportionately greater increase in the rate of synthesis. The rate of synthesis decreased to control levels once the trained animals ceased swimming.

Effect of Copper on Some Aspects of the Bioenergetics of Rainbow Trout (Salmo gairdneri)

1976 ◽  
Vol 33 (6) ◽  
pp. 1335-1342 ◽  
Author(s):  
Patrick F. Lett ◽  
G. J. Farmer ◽  
F. W. H. Beamish
Keyword(s):  
Rainbow Trout ◽  
Hard Water ◽  
Initial Response ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Initial Growth ◽  
Ration Level ◽  
Dry Food ◽  
Effect Of Copper ◽  
Sublethal Concentrations

The influence of sublethal concentrations of total copper on the appetite, growth, and proximate body composition of rainbow trout (Salmo gairdneri) held in hard water (365 mg/liter) was measured over a 40-day interval. The initial response of trout exposed to concentrations of copper ranging from 0.0 to 0.3 mg/liter (the 96-h LC50 was 0.25–0.68) was the cessation of feeding. Thereafter, food intake gradually returned to amounts observed for control fish, the rate of return of appetite being dependent on copper concentration and ration level. Growth rate of trout exposed to copper (0.075–0.225 mg/liter) and fed rations of either 0.25 or 1.5% dry food wt/wet fish wt per day was initially depressed but approached values observed for control fish near the end of the 40-day interval. During this period, lipid, protein, and moisture offish exposed to copper did not change significantly. Initial growth retardation was not attributable to the inability of copper-exposed fish to digest their daily rations. Results are discussed in terms of the ability offish to adapt to stress imposed by sublethal concentrations of heavy metals.

Blood respiratory properties of rainbow trout (Salmo gairdneri) kept in water of high CO2 tension

1977 ◽  
Vol 67 (1) ◽  
pp. 37-47 ◽  
Author(s):  
F. B. Eddy ◽  
J. P. Lomholt ◽  
R. E. Weber ◽  
K. Johansen
Keyword(s):  
Rainbow Trout ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Acid Base Balance ◽  
Acid Base ◽  
High Co2 ◽  
Plasma Bicarbonate ◽  
O2 Transport ◽  
Blood Ph ◽  
Base Balance

1. Blood O2 transport and acid-base balance were studied at 20 degrees C in rainbow trout (Salmo gairdneri) which had been kept in water of high CO2 content (15 mmHg) for at least a week. Also the blood gas chemistry of fish rapidly entering or leaving the hypercapnic environment was studied. 2. Fish entering high CO2 water suffered a sharp decrease in blood pH which significantly reduced O2 transport by the blood, but after a few hours considerable compensation was achieved. 3. After at least a week in high CO2 water, trout showed elevated plasma bicarbonate and PCO2 levels, and a decrease in plasma chloride, while pH was about 0 - 1 pH unit below the level for control fish. Oxygen transport by the blood was marginally reduced. 4. Hypercapnic fish rapidly entering fresh water showed a sharp increase in blood pH and a decrease in blood PO2. These parameters regained normal values after a few hours but plasma bicarbonate and chloride levels took much longer to regain control concentrations. 5. Acid-base balance in hypercapnic fish is discussed with particular reference to the role of the branchial ion exchanges.

scholarly journals Oxygen Consumption and Swimming Performance in Hypoxia-Acclimated Rainbow Trout Salmo Gairdneri

1984 ◽  
Vol 113 (1) ◽  
pp. 225-235 ◽  
Author(s):  
P. G. BUSHNELL ◽  
J. F. STEFFENSEN ◽  
K. JOHANSEN
Keyword(s):  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Swimming Performance ◽  
Relative Increase ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Swimming Velocity ◽  
Loading Capacity ◽  
Blood Oxygen ◽  
Normoxic Control

1. Swimming performance and oxygen consumption of normoxic (control) and hypoxia-acclimated (P002=40 mmHg) rainbow trout, Salmo gairdneri Richardson, were monitored at &gt;145, 60 and 40mmHg. 2. Maximum swimming velocity at 40mmHg was reduced from &gt;54.8cm s−1 to 41.4cm s1 in controls and to 40.6 cm s−1 in hypoxiaacclimated fish. 3. Normoxic oxygen consumption of control fish ranged from 97.5 mg O2 kg−1 h−1(5.5cm s−1) to 318.5 mg O2 kg−1 h−1 (54.8 cm s−1) and did not differ significantly from that of hypoxia-acclimated fish in normoxia. 4. Reduction of ambient P002 from normoxia to 60mmHg or 40mmHg did not significantly change oxygen consumption in control animals, although no fish (control or hypoxia acclimated) completed swimming trials at 54.8cm s−1 in 40mmHg. 5. Oxygen consumption of hypoxia-acclimated fish at 5.5cm s−1 and 40 mmHg was significantly higher than oxygen uptake in normoxia at the same speed. This relative increase was not maintained, however, as oxygen consumption at higher swimming speeds was similar to that in normoxia. 6. Blood studies showed that hypoxia-acclimated fish had lower ATP concentrations and P50 values. While these factors may increase the blood oxygen loading capacity, the change is apparently not enough markedly to improve swimming performance or oxygen consumption in hypoxia and/or exercise.

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