scholarly journals Effects of dietary moisture content of extruded diets on physical feed quality and nutritional response in Atlantic salmon (Salmo salar)

2014 ◽  
Vol 20 (4) ◽  
pp. 451-465 ◽  
Author(s):  
M. Oehme ◽  
T.S. Aas ◽  
H.J. Olsen ◽  
M. Sørensen ◽  
M. Hillestad ◽  
...  
Keyword(s):  
Moisture Content ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Feed Quality ◽  
Atlantic Salmon Salmo Salar

Changes in Gill ATPase Activity and Smolt Status of Atlantic Salmon (Salmo salar)

1978 ◽  
Vol 35 (12) ◽  
pp. 1542-1546 ◽  
Author(s):  
Richard L. Saunders ◽  
Eugene B. Henderson
Keyword(s):  
Moisture Content ◽  
Atlantic Salmon ◽  
Atpase Activity ◽  
Salmo Salar ◽  
Salinity Tolerance ◽  
Atlantic Salmon Salmo Salar ◽  
Photoperiod Regime ◽  
Natural Photoperiod ◽  
Salmon Smolt ◽  
Photoperiod Manipulation

Gill Na+K+-activated ATPase activity increased during winter–spring in Atlantic salmon (Salmo salar) held at 10 °C and subjected to simulated natural or reciprocal (light/dark ratio opposite that of natural) photoperiods. ATPase activity increased earlier and was greater under the reciprocal than under the natural photoperiod regime. Body lipid decreased and moisture content increased sooner and more sharply in reciprocal than in natural photoperiod fish. Salinity tolerance (to 40‰) increased between March and April. Exposure to 40‰ salinity for periods up to 14 d gave marked increases in ATPase activity over levels measured in freshwater. Gill ATPase activity is a sensitive indicator of the ability of Atlantic salmon to osmoregulate in seawater. Together with lipid-moisture content, tolerance to high salinity, and migratory behavior, gill ATPase activity provides a valid indication of smolt readiness to migrate to sea. Key words: smolt criteria, photoperiod manipulation, Atlantic salmon, smolt physiology, salinity tolerance, osmoregulation

scholarly journals Physical feed quality and starch content causes a biological response in Atlantic salmon (Salmo salar L)

2021 ◽  
Vol 21 ◽  
pp. 100791
Author(s):  
Tor Andreas Samuelsen ◽  
Marie Hillestad ◽  
Hans Jákup Jacobsen ◽  
Tor Johannes Hjertnes ◽  
Hanne Jorun Sixten
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Starch Content ◽  
Biological Response ◽  
Feed Quality ◽  
Atlantic Salmon Salmo Salar

Seawater Adaptation and Parr–Smolt Transformation of Juvenile Atlantic Salmon, Salmo salar

1978 ◽  
Vol 35 (1) ◽  
pp. 93-100 ◽  
Author(s):  
G. J. Farmer ◽  
J. A. Ritter ◽  
D. Ashfield
Keyword(s):  
Moisture Content ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Lipid Content ◽  
Condition Factor ◽  
Fork Length ◽  
Temperature Cycle ◽  
Seawater Adaptation ◽  
Migratory Activity ◽  
Atlantic Salmon Salmo Salar

Seawater adaptation of 1- and 2-yr-old Atlantic salmon, Salmo salar, presmolts and smolts was assessed during exposure to salinity increasing from 0.1 to 31‰ by examining changes in the osmotic concentration of their serum, urine, and intestinal fluid. Both age-classes adapted to seawater equally well; the marine osmoregulatory mechanisms apparently function before completion of parr–smolt transformation. Adaptation was possible during the parr stage for fish exceeding 12–13 cm fork length. The timing of transformation was synchronous for 1- and 2-yr-old juveniles as demonstrated by changes in their lipid and moisture content and condition factor (K). Condition factor of juveniles at the Mactaquac Hatchery, New Brunswick (45°58′N), decreased from February until the second half of May, while lipid content decreased from February until the second half of June. Migratory activity of juveniles at this location was maximal during the second half of May coincident with attainment of minimum K values and decreased during the first half of June as K values increased. While timing of changes in lipid and moisture content and K values were similar for juveniles at the Mersey Hatchery, Nova Scotia (44°10′N), lipid content of fish at the more southerly station decreased at a greater rate and migratory activity was apparent earlier. This was probably attributable to the advanced temperature cycle at that location. Smolt-release dates are discussed in terms of the development of the marine osmoregulatory mechanisms and the timing of parr–smolt transformation. Key words: Atlantic salmon, seawater adaptation, parr–smolt transformation, migration, hatchery management

Smolting Status of Downstream Migrating Atlantic Salmon (Salmo salar) Parr

1990 ◽  
Vol 47 (6) ◽  
pp. 1136-1139 ◽  
Author(s):  
Tim P. Birt ◽  
John M. Green ◽  
William S. Davidson
Keyword(s):  
Moisture Content ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Salinity Tolerance ◽  
Sodium Concentration ◽  
Plasma Sodium ◽  
Atlantic Salmon Salmo Salar ◽  
Plasma Sodium Concentration ◽  
Gradual Development ◽  
Freshwater River

Significant numbers of Atlantic salmon (Salmo salar) parr have been observed to accompany seaward migrating smolts in some rivers. Downstream migrating parr in Freshwater River Newfoundland, have lower salinity tolerance and branchial Na+–K+ ATPase activity than smolts. However, moisture content in downstream migrating parr was similar to that of smolts; both groups had higher mean moisture content than nonmigratory parr. Mean plasma sodium concentration was significantly higher than in smolts, but somewhat lower than in nonmigratory parr. Elevated moisture levels and slightly depressed plasma sodium concentrations are consistent with the view that seaward movement is associated with osmoregulatory imbalance in both parr and smolts. Brackish water found in estuaries appears important for gradual development of salinity tolerance in these migrants.

Physiological Smolt Characteristics of Anadromous and Non-anadromous Brook Trout (Salvelinus fontinalis) and Atlantic Salmon (Salmo salar)

1985 ◽  
Vol 42 (3) ◽  
pp. 529-538 ◽  
Author(s):  
Stephen D. McCormick ◽  
Robert J. Naiman ◽  
Ellyn T. Montgomery
Keyword(s):  
Moisture Content ◽  
Atlantic Salmon ◽  
Atpase Activity ◽  
Salmo Salar ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Salt Water ◽  
Physiological Factors ◽  
Low Salinity ◽  
Atlantic Salmon Salmo Salar

Anadromous brook trout, Salvelinus fontinalis, of rivière à la Truite, Quebec, were examined for physiological changes associated with smoltification, and compared with non-anadromous brook trout from the adjacent Matamek River. There were no statistical differences in plasma thyroxine concentration, gill Na+, K+-ATPase activity, hematocrit, or osmoregulatory ability between the populations. Moisture content was different between the populations, but both had the same pattern of declining moisture content as summer progressed. Silver coloration of brook trout in rivière à la Truite was associated with larger fish and higher gill Na+, K+-ATPase activity, but not with changes in plasma thyroxine concentrations, moisture content, hematocrit, or condition factor. Brook trout at high-salinity estuarine sites had greater gill Na+, K+-ATPase activity and hypoosmoregulatory ability than those from low-salinity sites. Silvering of Atlantic salmon (Salmo salar) in rivière à la Truite was associated with larger fish, higher gill Na+, K+-ATPase activity, and higher plasma thyroxine. Gill Na+, K+-ATPase activity of highly silvered freshwater Atlantic salmon was greater than that of highly silvered brook trout. Estuarine Atlantic salmon had significantly higher plasma thyroxine concentration and gill Na+, K+-ATPase activity than estuarine brook trout. Based on these physiological factors, we conclude that smoltification is undeveloped in brook trout and that estuarine residence is important for salt water acclimation and eventual seaward migration.

Microstructure and texture of fresh and smoked Atlantic salmon, Salmo salar L., fillets from fish reared and slaughtered under different conditions

2001 ◽  
Vol 32 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Sjofn Sigurgisladottir ◽  
Margret S. Sigurdardottir ◽  
Helga Ingvarsdottir ◽  
Ole J. Torrissen ◽  
Hannes Hafsteinsson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar

Persistence of Orally Administered Salmonella enterica Serovars Agona and Montevideo in Atlantic Salmon (Salmo salar L.)

2005 ◽  
Vol 68 (7) ◽  
pp. 1336-1339 ◽  
Author(s):  
L. L. NESSE ◽  
T. LØVOLD ◽  
B. BERGSJØ ◽  
K. NORDBY ◽  
C. WALLACE ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Salmonella Enterica ◽  
Most Probable Number ◽  
Fish Feed ◽  
Internal Organs ◽  
Probable Number ◽  
Atlantic Salmon Salmo Salar ◽  
Gastric Intubation

The objective of our experiments was to study the persistence and dissemination of orally administered Salmonella in smoltified Atlantic salmon. In experiment 1, salmon kept at 15°C were fed for 1 week with feed contaminated with 96 most-probable-number units of Salmonella Agona per 100 g of feed and then starved for 2 weeks. Samples were taken from the gastrointestinal tract and examined for Salmonella 1, 2, 8, 9, 15, and 16 days after the feeding ended. In experiment 2, Salmonella Agona and Montevideo were separately mixed with feed and administered by gastric intubation. Each fish received 1.0 × 108, 1.0 × 106, or 1.0 × 104 CFU. The different groups were kept in parallel at 5 and 15°C and observed for 4 weeks. Every week, three fish in each group were sacrificed, and samples were taken from the skin, the pooled internal organs, the muscle, and the gastrointestinal tract and examined for the presence of Salmonella. The results from the two experiments showed that the persistence of Salmonella in the fish was highly dependent on the dose administered. Salmonella was not recovered from any of the fish that were fed for 1 week with the lowest concentration of Salmonella. In the fish given the highest dose of Salmonella, bacteria persisted for at least 4 weeks in the gastrointestinal tract as well as, to some extent, the internal organs. The present study shows that under practical conditions in Norway, the risk of Salmonella in fish feed being passed on to the consumer of the fish is negligible.

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