Near infrared reflectance spectroscopy (NIRS) characterization of European sea bass (Dicentrarchus labrax) from different rearing systems.

The present study aimed to predict by NIRS the proximate chemical composition and some carcass traits of sea bass coming from 11 farms with different rearing systems (extensive, intensive in land-based basins, sea cages) and located in northern (Friuli, Veneto), central (Tuscany) and southern (Puglia and Sicily) Italy. NIRS analysis of freeze dried sea bass fillets gave fairly good predictions of slaughter weight and fillet yield (R2cv=0.48-0.55), while results for carcass yield were poor. NIRS analysis was highly predictive for the condition factor (R2cv=0.790, SECV=0.09) and for water, ether extract and gross energy showing high correlations (R2cv>0.90) with NIR spectral infor- mation and high accuracy (SECV=0.67%, 0.46% and 0.38 kJ/g for water, ether extract and energy, respectively). Crude protein prediction showed lower performance, even if still good, compared to pre- vious variables (R2cv=0.734, SECV=0.34). The score plot of principal component analysis showed in- tensively-reared sea bass separated from extensively reared fish

Poly-chlorinated biphenyls (PCB) in European sea bass from different rearing systems

The chemical composition and the level of seven indicator congeners of PCB (BZ/IUPAC no. 28, 52, 101, 118, 138, 153, and 180) were determined in 133 specimens of farm-raised European sea bass (Dicentrarchus labrax). The fish were caught from different aquaculture rearing systems: extensive fish valley, semi-intensive ponds, sea-cages, and intensive concrete tanks. Fresh fillet chemical composition differed among the rearing systems (fat: 2.9, 7.5, 7.1, and 9.4%; P<0.001). Total concentrations of indicator congeners were below the EU limit (200ng/g fat) for meat, poultry and eggs, being the lowest in extensively-reared sea bass (75ng/g fat), intermediate in sea bass from semi-intensive ponds (119) and sea cages (116), and the highest in intensively-reared fish (133) (P<0.001). Similarly, PCB concentrations in fresh fillets were 2,438, 10,116, 8,491, and 12,952pg/g in the four systems (P<0.001). The congener 153 was the most represented in all rearing systems. TEQ concentrations for the dioxin-like congener no. 118 were 50 to 200 times lower than the maximum admitted value. Total concentration of indicator congeners of PCB was poorly correlated with fish slaughter weight (R2=0.17), while highly correlated with fat concentration of fish (R2=0.75)

Immunohistochemical localization of constitutive and inducible heat shock protein 70 in carp (Cyprinus carpio) and trout (Oncorhynchus mykiss) exposed to transport stress.

In the present work we investigated by immunohistochemistry the cellular localization of constitutive as well as inducible heat shock protein 70 in several tissues of common carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss) exposed to transport stress. In carp, the constitutive form (HSC70) was detected only in red skeletal muscle of both control and stressed animals. In the same species, the inducible form (HSP70) was evident in the epithelia of renal tubules, gills and skin of stressed animals, whereas in controls only red skeletal muscle exhibited an immunopositivity to HSP70 antibody. In trout, immunostaining to HSC70 antibody was found mainly in the epithelia of intestine, gills and skin of both control and stressed animals although the reactivity was generally higher in animals exposed to transport stress. In the same species immunostaining to HSP70 antibody was observed only in red skeletal muscle and epidermis of control animals

EFFECT OF CAGE FLOOR AND STOCKING DENSITY ON GROWTH PERFORMANCE AND WELFARE OF GROUP-HOUSED RABBITS

ABSTRACT Two hundred forty rabbits weaned at 36 d (LW=1103±41 g) were housed in groups to evaluate the effect of stocking density and type of cage floor on behaviour, health status, growth performance, and carcass and meat quality. The rabbits were put in groups of 6 into 40 cages of two sizes (78 x 64 cm or 58 x 64 cm) corresponding to two stocking densities (D12, 12.1 rabbits/m 2 vs. D16, 16.2 rabbits/m 2 ). Within density, four types of floor were compared (steel slat, plastic slat, wire net and straw litter on wire net) according to a 2 x 4 factorial arrangement with five replications (cages). The rabbits were fed a unique diet (CP: 15.8%, ADF: 19.3%, DE: 9.8 MJ/kg). No antibiotic was added to feed or water. Rabbit reactivity was assessed by the tonic immobility and open-field tests at 70 and 74 d of age. Rabbits were slaughtered at 78 d to evaluate carcass and meat quality. Femur dimensions and resistance to fracture were measured. Sanitary status and growth performance were highly satisfying in all treatments: growth rate averaged 45.5 g/d and final weight 2967 g, with a feed conversion rate of 3.49. Stocking density did not affect growth performance, meat quality, nor animal reactivity. In contrast, the type of floor significantly affected growth performance: rabbits kept on straw bedded floor showed the lowest final weight (2865 g vs. 3000 g on average, P=0.03), weight gain and feed intake. Differences in carcass and meat quality mainly depended on the weight at slaughter: dressing percentage and separable fat of the carcass were lower (P&lt;0.01) in the lightest rabbits kept on straw (58.6% and 2.3%, respectively) compared to the heavier animals of the other three experimental groups (average values 59.9% and 3.0%, respectively). The type of floor also affected animal reactivity: the number of attempts necessary to induce immobility, considered inversely correlated with fear towards humans, was lower in rabbits kept on straw; these rabbits also showed a more passive reaction during the open field test, spending less time exploring and more time in an immobile state (P&lt;0.01) in comparison with the animals housed in the cages with plastic slat or wire net floors

Assessing freshness of European sea bass (Dicentrarchus labrax) from different farming systems

This study aimed to assess the evolution of freshness in 90 European sea bass (Dicentrarchus labrax) analyzed after 3, 6, 10, 13, and 17 days of storage in ice at 2\ub0C. Sea bass were caught in three farms characterized by different rearing systems (extensive coastal lagoons, intensive inland basins, intensive sea cages). At each storage time, sensory analysis for freshness was performed on intact fish according to the Quality Index Method (QIM); skin colour and body firmness were measured on raw fish with a Minolta spectrophotometer and a dynamometer with a 20-mm diameter cylindrical probe, respectively; pH was recorded on the fillets. Data were submitted to analysis of variance using the GLM procedure with rearing system, storage time and their interaction as the variability factors. From the 3rd to the 17th day of storage, red and yellow indexes measured on skin decreased (P&lt;0.01) as well as body firmness (from 28.9 to 23.4 N; P&lt;0.01). Fillet pH remained stable (about 6.30) until the 13th day of storage and then increased up to 6.45 (P=0.10) at the 17th day. The total QIM score significantly increased with the days of storage and reached the maximum value (14.7 over a maximum of 22.0) after 17 days; skin appearance, body firmness, and gill traits showed some degradation soon after 3 days of storage. In contrast, eye and abdomen traits showed some appreciable degradation only after 13 days of storage. All traits were affected by the rearing system (P&lt;0.01). In particular, sea bass from the extensive system degraded to a slower extent compared with those from the intensive systems: total QIM scores (averages of all storage times) were 7.45 vs. 8.83 and 9.33 (P&lt;0.001) for sea bass caught in extensive coastal lagoons vs. intensive inland basins and intensive sea cages. Moreover, in the sea bass reared in sea cages, skin appearance, body firmness and eye traits degraded quicker and to a greater extent compared to the fish from the other farming systems

Levels of dioxin-like polychlorinated biphenyls (DL-PCBs)and metals in European sea bass from fish farms in Italy

The study evaluated the levels of dioxin-like polychlorinated biphenyls (DL-PCBs) and metals in the fillet of medium (468 \ub1 92 g) and large (708 \ub1 135 g) European sea bass (Dicentrarchus labrax) from 11 Italian fish farms using different rearing systems. DL-PCB contamination was higher in fish grown in extensive coastal lagoons compared with intensive inland basins and intensive sea cages (28.5 vs. 9.13 and 13.1 pg Toxic Equivalents (TEQ)/g fat; P < 0.001). Copper concentrations were lower (0.810 vs. 0.993 and 1.071 mg/kg fw) and mercury was higher (0.025 vs. 0.006 and 0.003 mg/kg fw) (P < 0.001) in sea bass from extensive farms than from intensively farmed fish in inland or sea cage systems. Sea bass size did not affect DL-PCB and metal contamination. Even at the highest contamination levels detected in this study, European sea bass were always below risk for human health concerns and were considered safe for human consumption

Levels of dioxin-like polychlorinated biphenyls (DL-PCBs) and metals in European sea bass from fish farms in Italy

The study evaluated the levels of dioxin-like polychlorinated biphenyls (DL-PCBs) and metals in the fillet of medium (468 ± 92 g) and large (708 ± 135 g) European sea bass (Dicentrarchus labrax) from 11 Italian fish farms using different rearing systems. DL-PCB contamination was higher in fish grown in extensive coastal lagoons compared with intensive inland basins and intensive sea cages (28.5 vs. 9.13 and 13.1 pg Toxic Equivalents (TEQ)/g fat; P < 0.001). Copper concentrations were lower (0.810 vs. 0.993 and 1.071 mg/kg fw) and mercury was higher (0.025 vs. 0.006 and 0.003 mg/kg fw) (P < 0.001) in sea bass from extensive farms than from intensively farmed fish in inland or sea cage systems. Sea bass size did not affect DL-PCB and metal contamination. Even at the highest contamination levels detected in this study, European sea bass were always below risk for human health concerns and were considered safe for human consumption

Dietary supplementation with mannanoligosaccharides and \u3b2 glucans in growing rabbits. 2 Gut Barrier and intestinal microbiota after weaning

The aim of this work was to determine the effect of yeast mannanoligosaccharides (MOS; Actigen, Alltech) and yeast \u3b2-glucans on gut barrier and intestinal microbiota in rabbits. A control diet (C) was formulated to meet rabbit growth requirements. G1 and G2 diets were obtained by supplementing C diet with \u3b2-glucans from Saccharomyces cerevisiae (100 and 200 mg/kg respectively), M1 and M2 diets were supplemented with mannanoligosaccharides (Actigen, Alltech) (400 and 800 mg /kg respectively), and GM diet was supplemented with 100 mg/kg of \u3b2-glucans + 400 mg/kg of MOS. Ninety six rabbits weaned at 32 days of age were randomly assigned to the six experimental diets and slaughtered 15 days after weaning. The type of diet did not affect villus length and goblet cell counts, but crypt depth was reduced at the highest levels of MOS and \u3b2-glucans supplementation. Both MOS and \u3b2-glucans increased specific sucrose activity (P = 0.001) and soluble protein concentration (P < 0.05) in jejunal mucosa; they also modified ileal and caecal microbiota and modulated the immune response. Compared with the control diet, the supplementation with 200 mg/kg of \u3b2-glucans (G2) and 800 mg/kg of MOS (M2) reduced the expression of iNOS in ileum. Rabbits fed the M2 diet showed also the lowest mRNA abundance of IL6. In appendix, rabbits fed G2 showed increased IL6 expression and those fed the M2 reduced the expression of INF\u3b3. In conclusion, MOS and \u3b2-glucans changed intestinal microbiota and modulated the immune response by reducing the expression of some pro-inflammatory cytokines in ileum and caecum of weaned rabbits