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1.
Development and detection of phosphorus deficiency in Atlantic salmon, Salmo salar L., parr and post-smolts 总被引：4，自引：0，他引：4
A pathological condition was induced in Atlantic salmon, Salmo salar L., by feeding a diet severely deficient in phosphorus. Parallel results were obtained in two consecutive experiments, one in fresh water and one in sea water. The deficiency condition was first manifest as a reduction in whole-body calcium (Ca) and phosphorus (P) levels and the development of abnormally soft and malformed bones. In later stages, growth was severely impaired and there was elevated mortality compared with fish fed a diet with sufficient phosphorus.
Two semipurified casein-based test diets were used in the experiments. The low-P diet contained only the P from casein, 3.5 g kg−1 or 0.35%, whereas the reference diet was supplemented with P and contained 9.0 g kg−1 or 0.9%, The diets were fed to salmon parr in fresh water (initial weight 4.7 g) and to post-smolts in sea water (initial weight 113 g) for 12 and 15 weeks, respectively. In both experiments, the fish grew adequately for a prolonged period, whereas the whole-body Ca and P levels declined almost immediately. Within a few weeks, the whole-body P content was reduced to ≊ 65% of the initial value, and Ca to 40%. The reductions in mineral content were most severe in the mineral-rich tissues, bones and scales. On gross examination, all bony structures were abnormally soft. The ribs were wrinkly, and the spine displayed scoliotic changes. These changes were correlated to the reduction in bone mineralization, and were manifest at the time when reductions in growth rate could be noted.
After the deficient fish were fed adequate levels of P for 9 weeks, their whole-body mineral levels returned to normal. The bone lesions did not heal completely during the same period of time. 相似文献
Two semipurified casein-based test diets were used in the experiments. The low-P diet contained only the P from casein, 3.5 g kg
After the deficient fish were fed adequate levels of P for 9 weeks, their whole-body mineral levels returned to normal. The bone lesions did not heal completely during the same period of time. 相似文献
2.
Deformities of skeletal structures, the heart, and other organs are a recurrent problem in species used in intensive aquaculture.
Elevated egg incubation temperature appears to be a high risk factor in the development of these malformations, but the causal
relation has not been established. Our aim was to identify candidate genes involved in the development of heat induced deformities
in Atlantic salmon (Salmo salar). Temperature sensitive genes were isolated by RNA Arbitrarily Primed (RAP)-PCR. A total of 33 RAP-PCR products were successfully
sequenced, and the expression of eight identified genes was further examined by RT-PCR from pooled samples of heat exposed
embryos. Five of these genes were demonstrated to be temperature sensitive, of which four were shown to be up-regulated and
one was down-regulated at elevated water temperatures. The atrial natriuretic peptide (ANP) gene, which is a promising candidate for heart deformities, showed the highest level of heat induction. Three additional
RAP-PCR products identified as heterogeneous nuclear ribonucleprotein (hnRNP) A0, acyl CoA binding protein (ACBP) and mitochondrial (mt)-HSP70 showed up-regulated mRNA expression in response to elevated water temperature. The single down-regulated gene was identified
as an Atlantic salmon (Salmo salar) homolog of the cysteine and tyrosine-rich 1 (CYYR1) gene. This study demonstrated that a temperature elevation of only 4 °C during the early stages of the organogenesis in
Atlantic salmon induce altered expression of a number of genes, which are candidates for the development of heat induced deformities. 相似文献
3.
The development of a pathological condition in the distal intestine of Atlantic salmon, Salmo salar L., induced by dietary soybean meal, was studied in a 6-week feeding experiment. The fully developed condition, as observed after 3 weeks on the experimental diets, was characterized by: (1) a shortening of heights of the mucosal foldings; (2) a loss of the normal supranuclear vacuolization of the absorptive cells in the intestinal epithelium; (3) a widening of the central stroma within the mucosal foldings, with increased amounts of connective tissue; and (4) a profound infiltration of inflammatory cells in the lamina propria. The first signs of morphological changes were observed after 2 days on a diet containing a solvent extracted soybean meal, and within 7 days, all the above mentioned signs were observed. When the fish were subsequently transferred to a control diet, the mucosal folds were rebuilt from the base, resulting in an apparently functional epithelium after 3 weeks. Starved fish also exhibited characteristic changes of the mucosa, including a finely granular cytoplasm replacing the supranuclear vacuoles seen in the epithelial cells of normal fish. In addition, a pattern of irregularly spaced indentations developed in the epithelium of the simple folds. The condition induced by dietary soybean meal was classified as a no n-infectious subacute enteritis, and a pathogenesis involving immunological mechanisms is suggested. 相似文献
4.
A M Bakke‐McKellep C McL Press G Baeverfjord
Krogdahl T Landsverk 《Journal of fish diseases》2000,23(2):115-127
Extracted soybean meal (SBM) in the diet for Atlantic salmon, Salmo salar L., causes an inflammatory response in the distal intestine. The morphological changes of the epithelial cells and a characterization of the inflammatory cell infiltrate of the distal intestinal mucosa were studied using a panel of enzyme and immunohistochemical markers. The salmon (average body weight 927 g) used in the study were fed either a fishmeal‐based diet (control diet) or a diet in which 30% of the fishmeal protein was replaced with SBM protein (SBM diet). In salmon fed SBM, there were markedly reduced enzyme reactivities in the distal intestinal epithelial cells, both in the brush border [5′‐nucleotidase (5′N), Mg2+‐ATPase, alkaline phosphatase (ALP) and leucine aminopeptidase (LAP)] and in the intracellular structures [alkaline and acid phosphatase, non‐specific esterase (NSE) and alanine aminopeptidase (AAP)]. There appeared to be an increased presence of cells of monocytic lineage, including macrophages, as well as neutrophilic granulocytes and immunoglobulin (Ig) M in the lamina propria of the SBM‐fed fish. The mid intestine showed little response to the diet. The results suggest that toxic/antigenic component(s) of SBM affect the differentiation of the distal intestinal epithelial cells and may help explain the reduced nutrient digestibilities previously reported in salmonids fed extracted SBM. 相似文献
5.
A controlled experiment mimicking Atlantic salmon (Salmo salar) pre-smolt farming conditions showed that fish exposed to 150 and 175% super oxygenated water produced higher levels of
carbon dioxide with the subsequent decrease in water pH compared to control fish exposed to 100% O2. At the 7th day of exposure the hyperoxic fish showed larger individual variation in swimming activity compared to the controls.
The individual variance in activity, tail beat frequency and scattering in the tanks among super oxygenated fish decreased
from the 7th to the 21st day of exposure. The behavioural effects of hyperoxia were seen in relation to altered feed consumption
halfway through the experiment, lower body weight, and altered haematological variables at day 21 of exposure. Plasma chloride
was reduced in the exposed fish and haemoglobin decreased with increasing oxygen saturations. Plasma cortisol was elevated
only in the 150% oxygenated group at day 21, while no effect on osmolality was recorded. The alterations in physiology and
behaviour from day 7 to day 21 may be explained in terms of acclimation to increased oxygen saturations. This study shows
that behaviour may be used as an indication of impaired water quality that may influence animal welfare negatively and eventually
prevent an efficient production. 相似文献
6.
Grete Baeverfjord Ståle Refstie Per Krogedal 《Aquaculture (Amsterdam, Netherlands)》2006,261(4):1335-1345
Regurgitation (belching) of oil is a problem in sea farmed rainbow trout kept in water with fluctuating salinity. This often coincides with abdominal distension syndrome, which is associated with osmoregulatory stress and lipid indigestion. The present study investigated combined effects of water stability in extruded feeds and fluctuating water salinity on feed consumption, growth, nutrient digestibility, gastrointestinal transit, and accumulation of water and oil in the stomach of rainbow trout. Diets were produced with high or low water stability, which were characterised by a novel water stability test. In an initial 84 days growth experiment, each diet was fed to six groups of 772 g trout, of which three tanks were supplied with full-strength seawater, and three tanks were fluctuated between seawater and freshwater (7 h per day during 3 successive days per week). No significant effects were seen, although the feed intake appeared slightly lowered by low dietary water stability at fluctuating salinity. In a second experiment, each diet was fed to four groups of 1 kg trout, of which two tanks were supplied with full-strength seawater, and two tanks were fluctuated between seawater and brackish water (17‰ 7 h per day daily). Low water stability of the diet resulted in accumulation of oil in the stomach, and this response was worsened when the salinity of the rearing water fluctuated. It also corresponded with reduced lipid digestibility. Consequently, low water stability of the diet caused an oil separation in the stomach that may result in oil-belching in rainbow trout suffering from osmoregulatory stress. 相似文献
7.
Synnøve Helland Vegard Denstadli Kirsti Hjelde Anders Skrede Grete Baeverfjord 《Aquaculture (Amsterdam, Netherlands)》2006,261(2):603-614
The effects of graded levels of phytic acid on skeletal development and mineral deposition were investigated in an 80 day feeding trial with Atlantic salmon (Salmo salar L.) parr. The level of phytic acid had no significant effect on the phosphorus (P) content of either whole body or vertebral column of Atlantic salmon. Negative effects of high phytic acid levels were, however, found on whole body concentration of calcium (Ca), magnesium (Mg), and in the Ca:P ratio, and in the vertebral column concentration of zinc (Zn). A novel type of vertebral pathology was observed, hyper dense (HD) vertebrae. The HD vertebrae appeared denser on radiographic images, and they consisted of a denser trabecular network than the surrounding vertebrae. The number of fish with HD vertebrae increased from initially 16% to 45-60%, with a tendency of more fish with HD vertebrae with increasing dietary phytic acid content. The HD vertebrae are described and illustrated with radiographic images, whole mount staining, and histology. 相似文献
8.
Duplicate tanks of c.280 g Atlantic salmon (Salmo salar L.) were fed for 60 days on diets in which fishmeal was substituted with graded levels of extracted soybean meal (SBM) comprising 0%, 10%, 15%, 20%, 25% or 35% of total protein. The effects on feed intake, growth, feed conversion, apparent digestibility and utilization of macronutrients and energy, pathohistological response of the distal intestine (DI), activities of digestive enzymes in the mid and distal intestinal mucosa, and faecal trypsin and plasma insulin concentrations were studied. A negative, dose‐dependent effect of SBM was observed on nearly all performance parameters with a notable exception of feed intake. The lowest SBM inclusion level of 10% resulted in moderate pathohistological changes in the DI. Each subsequent increase in SBM level increased the number of fish displaying severe changes. In contrast to the mid‐intestine (MI), all enzyme activities in the distal intestinal mucosa decreased dose‐dependently with increasing SBM inclusion. Faecal trypsin increased up to an SBM inclusion level of 20% and then levelled off. Plasma insulin increased from 0% to 15% SBM inclusion and then decreased. The results suggest that caution should be exercised in the use of even low levels of extracted SBM in salmon feeds. 相似文献
9.
Two trials were initiated to investigate the consequences of including various soybean products in diets for Atlantic salmon Salmo salar L. on (1) mortality following infection by Aeromonas salmonicida ssp. salmonicida during a cohabitation challenge, and (2) the lysozyme and IgM content of the intestinal mucosa. Groups of salmon were fed control diets containing fishmeal as the sole protein source (Contr1 and Contr2, respectively), soy concentrate-containing diets (SoyConc1 and SoyConc2, respectively), or diets containing either solvent-extracted soybean meal (SoyMeal, trial 1) or soybean molasses (SoyMol, trial 2), an alcohol extract of soybean meal. Both SoyMeal and SoyMol caused enteritis-like changes in the distal intestine, which were not observed in fish fed the Contr1, Contr2, SoyConc1, or SoyConc2 diets. There were significant differences ( P < 0.05) in mortality between feeding groups following the A.s. salmonicida challenge: these differences were greatest in fish fed SoyMeal (65.6%), least in fish fed SoyConc1 (60.5%), and intermediate in the fish fed the Contr1 diet (62.9%). The SoyMol diet caused significantly ( P < 0.0001) increased levels of both lysozyme and IgM in the mid and distal intestinal mucosa. It is concluded that components of soybean meal and soybean molasses cause an inflammatory response in the distal intestine that may lead to increased susceptibility to furunculosis. 相似文献
10.
Xavier A. Gutirrez Jelena Kolarevic Harald Takle Grete Baeverfjord Elisabeth Ytteborg Bendik Fyhn Terjesen 《Aquaculture Research》2019,50(9):2687-2697
The present study examined the protective effects of water chloride (Cl?) towards nitrite toxicity in Atlantic salmon parr during 84‐day long nitrite exposure. Effects on growth, histology, blood indices and gene expression were studied at a fixed nominal Cl? concentration of 200 mg/L and at several water nitrite concentrations (0, 0.5, 2, 5 and 10 mg/L NO2?–N). The specific growth rate was significantly reduced during the first three weeks at a Cl:NO2?–N ratio of 21:1, suggesting the activation of coping mechanisms at the later stages of the experiment. No significant effect of nitrite on gill histology and mortality was found. Nitrite accumulated in plasma; however, a Cl:NO2?–N ratio of 104:1 or higher prevented nitrite entry. The concentration of NO2?–N in plasma was significantly reduced at the end of the study, supporting the hypothesis of coping mechanisms. Cystic fibrosis transmembrane conductance regulator (cftr)‐1 showed a significant up‐regulation at highest nitrite concentration on day 22, and in three of the highest exposure groups at the end of the experiment. Our findings suggest that a Cl:NO2?–N ratio above 104:1 should be maintained through episodes of nitrite accumulation in water during the production of Atlantic salmon parr. 相似文献