Póvoa de Varzim, Portugal
Póvoa de Varzim, Portugal

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Guerreiro I.,University of Porto | Peres H.,University of Porto | Castro C.,University of Porto | Perez-Jimenez A.,University of Porto | And 3 more authors.
Aquaculture Research | Year: 2014

The effect of dietary protein reduction balanced by an increase in carbohydrate (starch) level on growth performance, feed utilization and intermediary metabolism of Senegalese sole juveniles was evaluated at two temperatures, 12 and 18°C. For that purpose two isolipidic (16% lipids) diets were formulated to contain 550gkg-1 protein and 90gkg-1 starch (diet HP:LC), and 450gkg-1 protein and 200gkg-1 starch (diet LP:HC). Each experimental diet was fed to triplicate groups of 20 fish (initial body weight: 15.9g) within each temperature. Diets had no effect on growth and feed utilization. Temperature affected growth but not feed efficiency, with fish growing more at 18°C. Fatty acid synthetase and glutamate dehydrogenase activities were higher at 12°C than at 18°C while activity of the other measured enzymes was not affected by water temperature. Glucokinase and malic enzyme activities were lower while fructose 1,6-bisphosphatase activity was higher in fish fed the HP:LC diet. Our data suggest that protein can be reduced from 550 gkg-1 to 450 gkg-1 by increasing starch level in high lipid diets for Senegalese sole juveniles without affecting overall performance. A reduction in protein content through an increase in dietary starch decreases hepatic gluconeogenesis. Increasing temperature from 12°C to 18°C improves fish growth but does not affect feed efficiency. © 2012 John Wiley & Sons Ltd.


Cabral E.M.,Abel Salazar Biomedical Sciences Institute | Fernandes T.J.R.,University of Porto | Campos S.D.,University of Porto | Castro-Cunha M.,A. Coelho and Castro Lda | And 3 more authors.
Aquaculture | Year: 2013

The replacement of fish meal (FM) by increasing levels of plant protein (PP) sources 50% (PP50), 75% (PP75) and 100% (PP100) was compared to a control diet (FM) containing fish meal as the main protein source in ongrowing Senegalese sole (mean initial body weight:106g±15). These four diets were isonitrogenous and isolipidic (54% crude protein and 9% crude fat on a dry matter basis). By the end of the growth trial, groups fed PP50 and PP75 had a final body weight and daily growth index (DGI) similar to the FM fed group (200g and 0.8-0.9, respectively), whereas PP100 diet induced a significantly lower DGI (0.4). PP100 showed the highest feed conversion ratio (FCR) (2.4 vs 1.5) and the lowest protein gain (0.5 vs 0.9gkg-1ABWday-1). Nutrient intake of PP groups was statistically similar to the FM group. Apparent digestibility coefficients (ADCs) of nutrients did not differ significantly among treatments (p>0.05) and all PP diets induced lower fecal P losses than the FM group (33%).The highest PP levels (PP75 and PP100) resulted in decreased whole body lipid contents, thought PP100 showed the highest HSI and liver total lipids. In all groups, liver was the major lipid storage organ (13.96-28.57% WW). Muscle lipid content was low (1.3-1.6% WW) and did not vary significantly among treatments. Polyunsaturated fatty acid (PUFA) levels in muscle were also similar amongst dietary treatments and the two highest replacement levels (PP75 and PP100) were still effective in producing an n-3 PUFA rich product (29-30% of total fatty acids (WW)) similar to the FM group (33% of total fatty acids (WW)). Docosahexaenoic acid (DHA) was selectively retained in muscle (17-21% of total fatty acids (WW)) and neither DHA/EPA (Eicosapentaenoic acid) nor EPA/ARA (Arachidonic acid) ratios were significantly affected (p. >. 0.05) by dietary treatments. The sensory evaluation of cooked slices showed that the replacement of marine protein sources (FM) by PP blends did not have a significant impact on the majority of the descriptors, though visual freshness and whiteness of the PP75 flesh yielded the highest scores.Our results indicate that ongrowing Senegalese sole can effectively use diets with high levels of PP sources, up to 75% of FM replacement, without impairing feed intake, growth performance and protein utilisation whilst preserving high n-3 PUFA and DHA flesh content. © 2012 Elsevier B.V.


Costas B.,CIIMAR – Interdisciplinary Center of Marine and Environmental | Costas B.,Abel Salazar Biomedical Sciences Institute | Costas B.,FARO | Rego P.C.N.P.,CIIMAR – Interdisciplinary Center of Marine and Environmental | And 8 more authors.
Journal of Fish Diseases | Year: 2013

The present study aimed to investigate leucocyte responses to inflammation as well as some innate immune parameters of Senegalese sole, Solea senegalensis, following challenge with two strains of Photobacterium damselae subsp. piscicida belonging to the European and Japanese clones described for this bacterium. Pathogenicity assays were performed to assess the virulence of each Photobacterium damselae subsp. piscicida strain for sole. Subsequently, fish were intraperitoneally injected with phosphate-buffered saline (control) or two concentrations (2 × 102 and 2 × 106 CFU mL-1) of each bacterial strain and sampled after 6 and 24 h. Results showed that the European isolate induces a higher degree of response than the Japanese strain. While blood neutrophilia and monocytosis correlated well with the increase in neutrophil and macrophage numbers in the peritoneal cavity, fish infected with the European isolate presented higher peritoneal cell numbers than fish challenged with the Japanese strain. In addition, alternative complement pathway activity and respiratory burst of head kidney leucocytes increased significantly in fish infected with the European isolate. The enhanced innate immune response displayed by Senegalese sole challenged with the European isolate is probably due to the higher degree of virulence presented by this Photobacterium damselae subsp. piscicida strain. © 2012 Blackwell Publishing Ltd.


Reis B.,Abel Salazar Biomedical Sciences Institute | Cabral E.M.,Abel Salazar Biomedical Sciences Institute | Fernandes T.J.R.,University of Porto | Castro-Cunha M.,A. Coelho and Castro Lda | And 3 more authors.
Aquaculture | Year: 2014

The present study evaluates the long term (5. months) effects of feeding vegetable oil-based diets to Senegalese sole (Solea senegalensis) until market size. Extruded isonitrogenous and isoenergetic diets (56% crude protein and 20. kJ/g) were formulated to substitute 0 (CTRL), 50 (VO50) and 100% (VO100) of FO by a VO blend (rapeseed oil, RO, soybean oil, SO, and linseed oil, LO). A concomitant replacement of 50% FM and FO (VO50PP50) by plant protein sources (pea, soybean meal, potato concentrate, corn and wheat gluten) and oils was also evaluated. After the growth trial (140. days), fish were fed a fish oil-based diet (CTRL) over a period of 26. days and growth, flesh quality and organoleptic properties were determined. Results show that it seems possible to substitute up to 100% of FO by a VO blend, as well as concomitantly substituting 50% FO and FM by vegetable sources in on-growing Senegalese sole diets, without compromising growth performance and feed utilization. This species selectively retains highly unsaturated fatty acids (ARA and DHA) and seems to adapt well to a low dietary supply of these FAs. At the end of the growth out experiment fish fed VO50 diet showed a similar n. - 3 HUFA profile to the CTRL fed fish. Total FO substitution resulted in a strong reduction of muscle EPA content that was totally recovered after 26. days of re-feeding with a FO based diet. Despite the observed changes in fatty acid composition, sole fillets from fish fed 100% VO are very well accepted by fish consumers and still are good nutritional value end-products for human consumption, providing 1.5 times the RDI level (0.4. g per 100. g of muscle) of EPA. +. DHA. © 2014 Elsevier B.V.


Guerreiro I.,University of Porto | Peres H.,University of Porto | Castro-Cunha M.,A. Coelho and Castro Lda. | Oliva-Teles A.,University of Porto
Aquaculture Nutrition | Year: 2012

A 74-day trial was undertaken to evaluate the effects of temperature (16 and 22°C) and dietary protein/lipid ratio on the performance of juvenile Senegalese sole (mean body weight: 6.4g). Four experimental diets were formulated to contain two protein levels (550gkg-1 and 450gkg-1) combined with two lipid levels (80gkg-1 and 160gkg-1). Growth was higher at 22°C and within each temperature in fish fed diets 55P8L and 45P16L. Feed efficiency, N retention (% NI) and energy retention (% EI) were higher at 22 and at both temperatures in fish fed diet 55P8L. Temperature affected whole-body composition, with dry matter, protein, lipid and energy being higher and ash lower in fish kept at higher temperature. Independently of temperature, whole-body lipid, energy and ash were higher and protein was lower in fish fed the high-lipid diets. Visceral and hepatosomatic indices were not affected by diet composition but were higher in fish kept at 16°C. Liver glycogen and lipid contents and activities of glutamate dehydrogenase, alanine and aspartate aminotransferases were not affected by diet or water temperature. Malic enzyme (ME) and glucose 6-phosphate dehydrogenase activities were higher in fish fed the low-lipid diets. ME activity was higher at lower temperature. In conclusion, increasing water temperature from 16 to 22°C improves growth and feed efficiency of Senegalese sole juveniles; regardless of water temperature, the diet with 550gkg-1 protein and 80gkg-1 lipid promoted the best growth and feed efficiency. © 2011 Blackwell Publishing Ltd.

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