Observed Liver Changes in Rainbow Trout (Salmo gairdneri) Fed Varying Levels of a Casein–Gelatin Mixture and Herring Oil in Experimental Diets

1973 ◽  
Vol 30 (7) ◽  
pp. 1017-1020 ◽  
Author(s):  
D. J. Lee ◽  
J. H. Wales
Keyword(s):  
Rainbow Trout ◽  
Bile Duct ◽  
Cell Injury ◽  
Starch Content ◽  
Parenchymal Cell ◽  
Salmo Gairdneri ◽  
Bile Duct Proliferation ◽  
Protein Levels ◽  
Liver Changes ◽  
High Level

Young rainbow trout (Salmo gairdneri) were fed semipurified diets containing varying levels of herring oil, casein–gelatin (70–30), and starch for 18 weeks. Fish fed diets containing 53% protein and fat levels of 8 and 16% developed livers with abnormal nuclei, bile duct proliferation, and some parenchymal cell injury. The same level of protein with 24% herring oil did not produce these liver changes. Increasing protein levels with concurrent lowering of starch content produced large livers that were high in glycogen. This effect was not as pronounced at the high level (24%) of fat. The liver abnormalities apparently did not impair growth since weight gains were unrelated to the condition of the liver histology.

Digestibility and Utilization of Canola Meal in Practical-Type Diets for Rainbow Trout (Salmo gairdneri)

1986 ◽  
Vol 43 (6) ◽  
pp. 1149-1155 ◽  
Author(s):  
J. W. Hilton ◽  
S. J. Slinger
Keyword(s):  
Rainbow Trout ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Protein Digestibility ◽  
Salmo Gairdneri ◽  
Canola Meal ◽  
Feed Ingredient ◽  
High Fiber ◽  
Dry Matter Digestibility ◽  
High Level

The digestibility study indicated that dry matter digestibility of canola meal (CM) was low (56.2–60.4%), probably due to the high fiber content of this product and its relatively high level of complex carbohydrates. Energy and protein digestibility of CM were 72.4 and 83.2%, respectively, and the essential amino acid digestibilities were similar to those of protein in the CM. CM cannot successfully replace either soybean meal or fish meal in practical-type diets for young rainbow trout (Salmo gairdneri) without sacrificing growth. Supplementation with additional arginine, lysine and zinc, or energy to CM-based diets did not overcome the growth depressing effects. CM supplementation to the trout diet affected the thyroid gland of the fish, producing a diffuse, microfollicular hyperplasia that increased in severity with increasing CM supplementation. Young rainbow trout appear to be more sensitive to dietary glucosinolates than chinook salmon (Oncorhynchus tshawytscha), and total glucosinolate levels of 158 μg/g or more are deleterious to these fish. We conclude that CM should not, at this time, be included as a feed ingredient in commercial trout diets for young rainbow trout.

Ultrastructural and Clinicopathological Studies on the Toxicity of Cationic Acrylamide-based Flocculant to Rainbow Trout

1987 ◽  
Vol 24 (1) ◽  
pp. 34-43 ◽  
Author(s):  
M. Albassam ◽  
J. Moore ◽  
A. Sharma
Keyword(s):  
Rainbow Trout ◽  
Epithelial Cells ◽  
Blood Vessels ◽  
Cell Injury ◽  
Basement Membranes ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
Apical Plasma Membrane ◽  
Plasma Sodium ◽  
Secondary Lamellae

Rainbow trout (Salmo gairdneri) of two age groups were exposed to a cationic acrylamide-based flocculant at various concentrations in static bioassay chambers. At lethal concentrations the flocculant produced severe gill alterations in all fish. The principal alterations were necrosis and separation of the respiratory epithelial cells covering secondary lamellae. Many necrotic chloride cells were also seen, their apical plasma membrane was destroyed, and mitochondria were swollen with separated cristae. An influx of a large amount of fluid into the interstitial spaces caused partial or complete separation of subepithelial spaces from the covering epithelial cells and basement membranes of underlying blood vessels. Clinicopathological alterations included marked decreases in blood pH, partial pressure of oxygen, bicarbonate and plasma sodium, and chloride concentrations. Hematocrit, total protein, and blood glucose were increased. Fish exposed to sublethal concentrations had gill alterations characterized by hypercellularity and thickening of the secondary lamellae. These were due to undifferentiated cell proliferation and macrophage and lymphocyte infiltration between the covering epithelial cells and the underlying blood vessels. Macrophages and undifferentiated cells had large phagolysosomes containing cytoplasmic organelles, an indication of cell injury and increased turnover.

Influence of Salinity on Protein Requirements of Rainbow Trout (Salmo gairdneri) Fingerlings

1973 ◽  
Vol 30 (12) ◽  
pp. 1867-1873 ◽  
Author(s):  
I. H. Zeitoun ◽  
J. E. Halver ◽  
D. E. Ullrey ◽  
P. I. Tack
Keyword(s):  
Rainbow Trout ◽  
Protein Efficiency Ratio ◽  
Salmo Gairdneri ◽  
Efficiency Ratio ◽  
Protein Requirements ◽  
Protein Levels ◽  
Major Consequence ◽  
Percentage Weight ◽  
Net Protein ◽  
Representative Samples

Rainbow trout (Salmo gairdneri) juveniles maintained at 10 and 20 ppt salinity were fed seven diet treatments from 30 to 60% protein in 5% increments for 10 weeks. The fish were stocked in cones, initially 50 fish per cone. Biweekly weights of diets and fish were determined and mortality was recorded daily. Percentage weight gain, gross diet efficiency, and protein efficiency ratio (P.E.R.) were computed. The minimum protein levels required for fish to achieve highest performance using these criteria were 40 and 45% for those maintained at 10 and 20 ppt, respectively. Mortality was significantly (P < 0.05) higher for fish maintained at the higher salinity. Analyses of the fish carcasses were conducted at the beginning and end of the experiment on representative samples to estimate the grams protein retained and apparent net protein utilization (N.P.U.) to verify the above findings. All the available data showed that dietary protein was of major consequence on all measurements until the minimum required level of protein in the diet was reached, while salinity was of minor consequence. P.E.R. and apparent N.P.U. were 2.10 and 34.4, respectively, for casein diets at the 40% protein level.

ELECTROPHORETIC VARIATION AND DIFFERENTIATION IN FOUR STRAINS OF DOMESTICATED RAINBOW TROUT (SALMO GAIRDNERI)

1979 ◽  
Vol 21 (1) ◽  
pp. 81-94 ◽  
Author(s):  
Craig A. Busack ◽  
Richard Halliburton ◽  
G. A. E. Gall
Keyword(s):  
Rainbow Trout ◽  
Genetic Variability ◽  
Genetic Differentiation ◽  
Balancing Selection ◽  
Genetic Distances ◽  
Salmo Gairdneri ◽  
Wild Populations ◽  
Electrophoretic Variation ◽  
High Level

A total of 1462 rainbow trout (Salmo gairdneri Richardson) representing four California domestic strains, were examined electrophoretically at 24 gene loci to investigate the amount of genetic variability within strains and genetic differentiation between strains, relative to wild populations. Estimated heterozygosities of 0.071 to 0.134 were similar to those reported for wild populations and thus indicated that the domestic strains were at least as variable as wild populations. Genetic distances between strains ranged from 0.011 to 0.067, values typical of the level of differentiation observed between local conspecific populations in a variety of organisms. It was suggested that this high level of heterozygosity is due to mixing of populations in the strains' histories and perhaps also to balancing selection.

The ultrastructure of the liver of the rainbow trout: normal structure and modifications after chronic administration of a polychlorinated biphenyl Aroclor 1254

1978 ◽  
Vol 56 (3) ◽  
pp. 477-491 ◽  
Author(s):  
M. A. Hacking ◽  
Joan Budd ◽  
K. Hodson
Keyword(s):  
Endoplasmic Reticulum ◽  
Rainbow Trout ◽  
Polychlorinated Biphenyl ◽  
Smooth Endoplasmic Reticulum ◽  
Chronic Administration ◽  
Normal Structure ◽  
Salmo Gairdneri ◽  
Aroclor 1254 ◽  
Mammalian Liver ◽  
Liver Changes

Rainbow trout (Salmo gairdneri) were fed dietary levels of 0-, 1-, 10-, and 100-ppm Aroclor 1254 for 229 to 330 days. The ultrastructural features of control livers were similar to those of other animals, but rainbow trout liver differed from mammalian liver in an apparent absence of Kupffer cells. Also small dense duct-type cells were present that formed a transition zone, combining with hepatocytes to form canaliculi; alone they formed preductules and in combination with cells of lower density they formed ductules. Microtubules were found in the vicinity of canaliculi and less frequently adjacent to the plasma membrane of other cell surfaces. They were not seen at the sinusoidal border as they are in mammalian liver. Peroxisomes lacked nucleoids. There were no ultrastructural liver changes in the 1-ppm group. The most frequently encountered alterations in both the 10- and 100-ppm groups were those involving the nucleus. These included irregular and bizarre nuclear outlines, separation of nucleolar components, and large nuclear pseudoinclusions. Other frequently encountered changes were slight increases in smooth endoplasmic reticulum, altered rough endoplasmic reticulum, increased lysosomes, reduced and altered glycogen, increased lipid, and hypoxic vacuoles. Seen also were concentric membrane arrays, myelin figures in intercellular spaces and Golgi cisternae, and bundles of fine tubules throughout the cytoplasm.

Effects of Water Salinity and Dietary Protein Levels on Total Serum Protein and Hematocrit of Rainbow Trout (Salmo gairdneri) Fingerlings

1974 ◽  
Vol 31 (6) ◽  
pp. 1133-1134 ◽  
Author(s):  
Ibrahim H. Zeitoun ◽  
Duane E. Ullrey ◽  
Peter I. Tack
Keyword(s):  
Rainbow Trout ◽  
Serum Protein ◽  
Dietary Protein ◽  
Water Salinity ◽  
Salmo Gairdneri ◽  
Total Serum Protein ◽  
Total Serum ◽  
Protein Levels ◽  
Salinity Water ◽  
Different Levels

Seven separate diets ranging from 30 to 60% protein in 5% increments were fed for 10 wk to duplicate groups of rainbow trout, Salmo gairdneri, fingerlings maintained at 10 and 20‰ salinity. Water salinity and dietary protein concentration did not significantly influence total serum protein. Hematocrit increased substantially with salinity (35.3% for fish at 10 ppt and 39.1% for those at 20 ppt), whereas different levels of dietary protein were of minor consequence.

Iodine Balance in Rainbow Trout (Salmo gairdneri) and Effects of Testosterone Propionate

1979 ◽  
Vol 36 (3) ◽  
pp. 282-285 ◽  
Author(s):  
David W. C. Hunt ◽  
J. G. Eales
Keyword(s):  
Body Weight ◽  
Rainbow Trout ◽  
Thyroid Hormones ◽  
Key Words ◽  
Testosterone Propionate ◽  
Iodine Content ◽  
Salmo Gairdneri ◽  
Elevated Plasma ◽  
Protein Levels ◽  
Plasma Pool

Iodine balance was studied in immature rainbow trout (Salmo gairdneri) held at 12 °C in water of iodine content 1.85 μg/L and fed daily 1% of body weight with food containing 0.48 μg I/g. Iodide flux into the plasma pool was 148 ng I∙h−1∙100 g−1 of which < 1% was contributed by peripheral deiodination of thyroid hormones, up to 16% was obtained from the diet, and at least 84% was derived from the water. Less than 5% of iodide intake was required to satisfy thyroidal secretory demands. Testosterone injections elevated plasma iodide and protein levels, but did not alter the rate of plasma iodide turnover. Key words: trout, iodine balance, thyroid function, testosterone

Effect of Increased Dietary Fiber on the Growth of Rainbow Trout (Salmo gairdneri)

1983 ◽  
Vol 40 (1) ◽  
pp. 81-85 ◽  
Author(s):  
J. W. Hilton ◽  
J. L. Atkinson ◽  
S. J. Slinger
Keyword(s):  
Rainbow Trout ◽  
Dietary Fiber ◽  
Liver Glycogen ◽  
Feed Consumption ◽  
Salmo Gairdneri ◽  
Growth Depression ◽  
Protein Levels ◽  
Iron And Zinc ◽  
Stomach Volume ◽  
Kidney Liver

Juvenile rainbow trout (Salmo gairdneri) reared for 12 wk on different levels of dietary fiber showed a significant growth depression at levels of 10 and 20% alpha-floc (α-cellulose). The trout adapted to increased dietary fiber by increasing feed consumption, gastric evacuation time, and possibly by increasing the stomach volume and/or distensibility. The dry matter digestion coefficients of the diets declined as the fiber level increased, indicating that the digestibility of α-cellulose was not significantly different from zero. No effect of increased dietary fiber (alpha-floc) was detected on the liver glycogen levels, liver–body weight ratios, hemoglobin, hematocrit, plasma glucose, and plasma protein levels or the kidney, liver, and carcass levels of copper, iron, and zinc. We conclude that dietary fiber levels for rainbow trout should be less than 10% of the diet.Key words: rainbow trout, dietary fiber, maximum fiber level, fiber digestibility

Influence of Dietary Protein and Lipid on Apparent Heat Increment of Rainbow Trout, Salmo gairdneri

1986 ◽  
Vol 43 (1) ◽  
pp. 19-25 ◽  
Author(s):  
S. M. LeGrow ◽  
F. W. H. Beamish
Keyword(s):  
Rainbow Trout ◽  
Energy Intake ◽  
Dietary Protein ◽  
Diet Composition ◽  
Lipid Level ◽  
Dietary Lipid ◽  
Salmo Gairdneri ◽  
Dietary Energy ◽  
Protein Levels ◽  
Heat Increment

Oxygen uptake attributable to apparent heat increment (AHI) in rainbow trout, Salmo gairdneri (10–15 g), induced to swim at [Formula: see text] was influenced by dietary energy intake and diet composition. Twelve balanced diets were tested, with protein levels of [Formula: see text], 40, 48 and 60% and lipid levels of [Formula: see text], 15, and 23% factorally combined. Diets supplying 34% protein and 23% lipid (protein to energy ratio of 94.3 mg∙kcal−1) resulted in the lowest AHI of all diets tested, indicating most efficient utilization of dietary protein. At a dietary lipid level of 23%, dietary protein levels lower than 34% may result in a further reduction in AHI. Duration of elevated metabolism following feeding was independent of dietary protein and lipid level, as well as dietary energy intake. AHI of rainbow trout represented the equivalent of 15–24% of the digestible energy intake, depending on diet composition. A reduction in dietary protein with a concomitant increase in dietary lipid in the formulation of feeds for aquaculture purposes could enhance growth efficiency by reducing the energy expenditure for AHI.

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