Bt-maize (MON810) and non-GM soybean meal in diets for Atlantic salmon (Salmo salar L.) juveniles - Impact on survival, growth performance, development, digestive function, and transcriptional expression of intestinal immune and stress responses

Responses in Atlantic salmon (Salmo salar L.) juveniles (fry) fed diets containing genetically modified maize (Bt-maize, MON810) expressing Cry1Ab protein from first-feeding were investigated during a 99-day feeding trial. Four experimental diets were made; each diet contained ,20% maize, either Bt-maize or its near-isogenic maternal line (non-GM maize). One pair was fishmeal-based while the other pair included standard (extracted) soybean meal (SBM; 16.7% inclusion level), with the intention of investigating responses to the maize varieties in healthy fish as well as in immunologically challenged fish with SBM-induced distal intestinal inflammation, respectively. Three replicate tanks of fry (0.1760.01 g; initial mean weight 6 SEM) were fed one of the four diets and samples were taken on days 15, 36, 48 and 99. Survival, growth performance, whole body composition, digestive function, morphology of intestine, liver and skeleton, and mRNA expression of some immune and stress response parameters in the distal intestine were evaluated. After 99 days of feeding, survival was enhanced and the intended SBM-induced inflammatory response in the distal intestine of the two groups of SBM-fed fish was absent, indicating that the juvenile salmon were tolerant to SBM. Mortality, growth performance and body composition were similar in fish fed the two maize varieties. The Bt-maize fed fish, however, displayed minor but significantly decreased digestive enzyme activities of leucine minopeptidase and maltase, as well as decreased concentration of gut bile salts, but significantly increased amylase activity at some sampling points. Histomorphological, radiographic and mRNA expression evaluations did not reveal any biologically relevant effects of Bt-maize in the gastrointestinal tract, liver or skeleton. The results suggest that the Cry1Ab protein or other compositional differences in GM Bt-maize may cause minor alterations in intestinal responses in juvenile salmon, but without affecting overall survival, growth performance, development or health

Thermal injuries in Atlantic salmon in a pilot Laboratory trial

Thermal delousing is a new method for removing sea lice from farmed Atlantic salmon (Salmo salar L). We investigated thermally-related tissue injuries in Atlantic salmon in a pilot laboratory trial to describe the acute effect of high water temperatures (34–38 °C). Acute tissue injuries in gills, eyes, brain and possible also nasal cavity and thymus were seen in salmon exposed to water temperatures of 34 - 38 °C in 72 to 140 s. This implies that exposing salmon to such water temperatures is a welfare risk, not only due to the direct tissue injuries that may also be dependent on exposure time, but also due to risk of thermal pain and aversion, including flight reactions

Mykobakteriose hos laksefisk

Source at https://www.kyst.no/paywall?redirect=/profile/magazines-all. Mykobakterier er utbredt i naturen, med et stort antall beskrevne arter, hvorav noen er assosiert med sykdom hos mennesker og dyr. Mykobakteriose hos fisk er vanligvis en kronisk sykdom, med varierende dødelighet, og kan forårsake store økonomiske tap

Исследование возможности получения водорода в процессах фотокаталитической деградации органических загрязнителей воды с использованием Fe-содержащих композитов

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Does the thermal component of warm water treatment inflict acute lesions on Atlantic salmon (Salmo salar)?

Warm water treatment, i.e. exposure to sea water at a temperature of 28–34 °C for 20–30 s, has in recent years been widely used for delousing of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) in Norwegian aquaculture. High mortality and various lesions (e.g. injuries and/or bleedings in skin, fins, eyes, brain, and gills) have, however, been reported after industrial warm water treatments. The objective of this study was to reveal whether the thermal component of warm water treatment inflicts acute lesions on Atlantic salmon. The study was conducted by exposing individual, sedated Atlantic salmon post-smolts ( = 1117 ± 250 g) to sea water at a temperature of 34 °C (warm water treatment, n = 40) or 9 °C (control treatment, n = 20) for 30 s, and subsequently conducting welfare indicator scoring and histopathological examination of their skin, fins, eyes, snout, nasal pits/mucosa, palate, gills, thymus, pseudobranch, brain, heart, liver, kidney, pyloric caeca, pancreas, and spleen. The results showed that the prevalence and severity of acute lesions were not significantly different between the two treatment groups, except for higher prevalence of injuries on the caudal (p = 0.002), dorsal (p = 0.002), and right pelvic fins (p = 0.014) in the warm water treatment group. The main cause of these fin injuries may have been a strong behavioural reaction displayed by the fish when exposed to warm water. Possible consequences of fin injuries, the use of anaesthetic, and statistical limitations were discussed. It was concluded that exposure of Atlantic salmon to sea water at a temperature of 34 °C for 30 s did not lead to any statistically significant change in the prevalence of acute lesions except an increase in minor, possibly behaviour-related, fin injuries. Detection of a lower lesion prevalence than was possible in this study, but which may concern many individuals in an industrial setting, requires examination of a larger number of fish

Does the thermal component of warm water treatment inflict acute lesions on Atlantic salmon (Salmo salar)?

Warm water treatment, i.e. exposure to sea water at a temperature of 28–34 °C for 20–30 s, has in recent years been widely used for delousing of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) in Norwegian aquaculture. High mortality and various lesions (e.g. injuries and/or bleedings in skin, fins, eyes, brain, and gills) have, however, been reported after industrial warm water treatments. The objective of this study was to reveal whether the thermal component of warm water treatment inflicts acute lesions on Atlantic salmon. The study was conducted by exposing individual, sedated Atlantic salmon post-smolts ( = 1117 ± 250 g) to sea water at a temperature of 34 °C (warm water treatment, n = 40) or 9 °C (control treatment, n = 20) for 30 s, and subsequently conducting welfare indicator scoring and histopathological examination of their skin, fins, eyes, snout, nasal pits/mucosa, palate, gills, thymus, pseudobranch, brain, heart, liver, kidney, pyloric caeca, pancreas, and spleen. The results showed that the prevalence and severity of acute lesions were not significantly different between the two treatment groups, except for higher prevalence of injuries on the caudal (p = 0.002), dorsal (p = 0.002), and right pelvic fins (p = 0.014) in the warm water treatment group. The main cause of these fin injuries may have been a strong behavioural reaction displayed by the fish when exposed to warm water. Possible consequences of fin injuries, the use of anaesthetic, and statistical limitations were discussed. It was concluded that exposure of Atlantic salmon to sea water at a temperature of 34 °C for 30 s did not lead to any statistically significant change in the prevalence of acute lesions except an increase in minor, possibly behaviour-related, fin injuries. Detection of a lower lesion prevalence than was possible in this study, but which may concern many individuals in an industrial setting, requires examination of a larger number of fish

Formulation and proximate composition (as fed basis) of the experimental diets.

a<p>Norseco-LT, Norsildmel, Bergen, Norway.</p>b<p>Extracted soybean meal, Denofa As, Fredrikstad, Norway.</p>c<p>NorSalmOil, Norsildmel, Bergen, Norway.</p>d<p>Normin AS, Hønefoss, Norway. Diets supplied with following vitamins per kg diet: vitamin D3, 3000 I.E; vitamin E (Rovimix, 50%), 160 mg; thiamine, 20 mg; riboflavin, 30 mg; pyridoxine-HCl, 25 mg; vitamin C (Riboflavin Stay C 35%), 200 mg; calcium pantothenate, 60 mg; biotin, 1 mg; folic acid, 10 mg; niacin, 200 mg; vitamin B₁₂, 0.05 mg; menadione bisulphate, 20 mg.</p>e<p>Normin AS, Hønefoss, Norway. Diets supplied with following minerals per kg diet: magnesium, 750 mg; potassium, 800 mg; zinc, 120 mg; iron, 60 mg; manganese, 30 mg; copper, 6 mg and selenium; 0.3 mg.</p>f<p>Gross energy was calculated using the energy concentrations of 39.5 for lipid, 23.6 for protein, and 17.2 kJ/g for carbohydrates (carbohydrate levels in diets were calculated as: 100 – [water + crude protein + crude lipid + ash]).</p

Mean whole body composition of Atlantic salmon juveniles fed non-GM maize or <i>Bt</i>-maize without or with soybean meal (SBM) for 99 days.

<p>Means and pooled standard errors (pSE) were calculated from pooled samples of 20 fish per tank, three replicate tanks per treatment group (n = 3).</p><p>The <i>p</i> values are given for the main variables non-GM/GM and non-SBM/SBM inclusion, respectively, as well as <i>p</i> values for interactions between the variables by two-way ANOVA analysis.</p><p>*Gross energy was calculated using the energy concentrations of 39.5 for lipid, 23.6 for protein, and 17.2 kJ/g for glycogen (glycogen levels were calculated as: 100 – (water + crude protein + crude lipid + ash).</p

Radiographic examination of the skeleton in Atlantic salmon juveniles fed non-GM maize or GM maize (<i>Bt</i>-maize) without or with soybean meal (SBM) for 99 days.

<p>The three figures illustrate various deformities observed in five of the 656 fish examined: vertebral fusion (arrow; A) and compressed vertebrae in neck region (oval; B and C). A normal vertebral axis is demonstrated in A and B, while C shows a slight axis deviation. See text for more details.</p

Mean cumulative mortality (number of individuals per period and total), growth performance, condition factor and specific growth rate (SGR) of Atlantic salmon juveniles fed non-GM maize or <i>Bt</i>-maize without or with soybean meal (SBM) from first-feeding to day 99.

<p>Means and pooled standard errors (pSE) were calculated from the means of three replicate tanks per treatment group (n = 3), with measurements performed on 10 fish per tank.</p><p>Initial body weight (g): 0.17±0.01; initial body length (cm): 2.5±0.1; initial condition factor: 1.04±0.08.</p><p>The <i>p</i> values are given for the main variables non-GM/GM and non-SBM/SBM inclusion, respectively, as well as <i>p</i> values for interactions between the variables by two-way ANOVA analysis.</p