Ascorbate-2-sulfate as a dietary vitamin C source for atlantic salmon (Salmo salar): 1. Growth, bioactivity, haematology and humoral immune response

Glette

Raa-Nilsen

et al. 1993

Presmolt Atlantic salmon were fed a fish meal based experimental diet supplemented with graded levels of ascorbate-2-monophosphate (AP), equivalent to 40, 400, 2000 and 4000 mg ascorbic acid (AA)/kg for 6 months prior to a bacterial challenge experiment. The liver AA concentration reflected the dietary intake of AP, but not linearly. Growth, hematology and acid phosphatase activity in zymosan stimulated macrophages were not affected by dietary AP. Serum hemolytic complement activity was higher in fish fed the highest AP level, but the variation was not significant. Production of specific antibodies was significantly higher in fish fed the highest AP level 11 and 17 weeks after vaccination. Bacterial challenge with Aeromonas salmonicida showed increased survival in the 4000 AP group. Lysozyme activity in headkidney and serum complement activity and serum iron in fish surviving the challenge were higher in the 4000 AP group, indicating important roles of vitamin C on lysozyme, complement and iron in non-specific disease resistance. The results indicate that high dietary levels of AP favourably affect health in Atlantic salmon. Disease resistance was, however, not correlated with the AA status in the liver.

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dietary vitamin C, immunity and disease resistance in Atlantic salmon (Salmo salar)

Glette

Raa-Nilsen

et al. 1993

“…A prime function of AA appears to be that of a reducing agent maintaining metaloenzymes in a reduced and active state (Padh 1991). Examples of physiological effects of AA demonstrated in fish are related to reproduction (Sandnes et al 1984;Soliman et al 1986;Waagb0 et al 1989), immune functions and disease resistance (Durve and Lovell 1982;Navarre and Halver 1989;Hardie et al 1991), iron metabolism and hematology (Hilton et al 1978;Maage et al 1990;Sandnes et al 1990), lipid metabolism (John et al 1979;Waagb0 et al 1989), interactions with other micronutrients (Hilton 1989, Maage et al 1990, stress (Wedemeyer 1969), brain neurotransmitters (Johnston et al 1989) and en- (Pang 1971;Thomas and Neff 1984). The AA requirement is thus influenced by many factors, and it is therefore necessary to establish the minimum required dietary level to avoid deficiency symptoms and to support growth under a variety of normal conditions.…”

Section: Introductionmentioning

confidence: 99%

The minimum dietary requirement of vitamin C in Atlantic salmon (Salmo salar) fry using Ca ascorbate-2-monophosphate as dietary source

Sandnes

Torrissen²,

1992

The minimum dietary vitamin C requirement for optimal growth and normal development in Atlantic salmon (Salmo salar) fry at the onset of feeding was studied, using Ca ascorbate-2-monophosphate (AP) as dietary source. The requirement was established by means of a feeding study lasting for 23 weeks from the beginning of feeding. The practical diets used were supplemented with AP at levels of 0, 10, 20, 40, 80 and 160 mg ascorbic acid (AA) equivalents/kg. Growth, mortality, hydroxyproline content in skin and backbone, and AA in liver were recorded to evaluate the results. The results suggest that the minimum dietary requirement for optimal growth and normal development is in the range of 10-20 mg AA equivalents/kg dry diet during the period studied.

“…Ascorbate-2-sulfate (AS) has been suggested as a stable vitamin C source in fish diets (Tucker and Halver 1986) and has been used commercially. Recent studies have shown that the bioactivity of this compound is limited in Atlantic salmon, Salmo salar (Sandnes et al 1990) and in rainbow trout, Oncorhynchus mykiss (Dabrowski and Kock 1989).…”

Section: Introductionmentioning

confidence: 99%

“…A detailed description of the experimental design, antigen injection and antibody detection is given by Sandnes et al (1990). The copper, zinc and cadmium content in each injected dose was 55 ng, 6 ng and < 0.15 ng, respectively.…”

Section: Introductionmentioning

confidence: 99%

Ascorbate-2-sulfate as a dietary vitamin C source for Atlantic salmon (Salmo salar): 2. Effects of dietary levels and immunization on the metabolism of trace elements

Maage

Olsson

et al. 1990

Atlantic salmon fingerlings were fed a vitamin C deficient diet for four months. The fish were then provided a dry, practical fishmeal based diet supplemented with 0, 500 or 5000 mg vitamin C/kg as L-ascorbic acid or equivalent amounts of ascorbate-2-sulfate. After six weeks on these diets ten fish in each group were injected with a soluble antigen (NIP11-LPH). Six weeks thereafter blood, liver, kidney, spleen and vertebrae were examined for trace elements. The livers were also analysed for metallothionein.The vitamin C deficient fish were anemic despite the significantly elevated iron concentrations in the liver. Vitamin C had no positive effect in lowering tissue levels of cadmium. The highest level of dietary vitamin C given as ascorbic acid reduced the liver selenium concentrations. In response to antigen injection, the fish in all groups showed increased levels of hepatic metallothionein, copper, zinc and cadmium, while hepatic selenium and iron levels were less affected. The elemental composition in other organs was affected by the antigen injection to a minor extent.