Franco Daprà

Rice protein-concentrate meal as a potential dietary ingredient in practical diets for blackspot seabream Pagellus bogaraveo: a histological and enzymatic investigation

Field and laboratory studies were conducted to evaluate the intestinal responses to partial replacement of fish meal with rice protein concentrate (RPC) in practical diets for blackspot seabream Pagellus bogaraveo. Two experimental diets were formulated to be isoproteic and isoenergetic with an increasing level of RPC (20 and 35%, respectively) and were tested against a fish meal-based control diet (RPC0). The diets showed similar features for growth performances and both intestinal histology and digestive enzymes. This study confirmed that RPC does not induce intestinal mucosa alterations in this fish. The dietary RPC supplement caused a significant increase in trypsin activity, whereas lipase activity was reduced.

Morphometry, slaughtering performances, chemical and fatty acid composition of the protected designation of origin “Golden hump tench of Poirino highland” product

One hundred and thirty-two tench were photographed and a total of 13 landmarks were identified. Fish were grouped in four size classes on length basis and different shape descriptors were computed. Landmark configurations were superimposed. Size was computed as centroid size. The roundness coefficient, the log(partial area)/log(total area) ratio and the condition coefficient were calculated. Slaughtering performances and fillet composition analyses were performed. Shape variability was found primarily on cephalic area while head and tail regions were more homogeneous. A high correlation between centroid size and total length was found as well as a higher increase of the partial area than the total area justifying the hump shape of this tench. The scatter of relative warp 1 scores and centroid size for the four size classes has showed, with the increase of the length, a larger number of specimens that were characterised by a deep profile. Geometric morphometric approach produced a valuable tool in defining morphospaces for tench. Condition coefficient ranged from 1.24 to 1.29, without any significant difference among the size classes. Slaughtering performance resulted in agreement with those reported by other authors while VSI was lower. In fillets, the fatty acid profile was composed of about 30% of saturated fatty acids, 50% of monounsaturated fatty acids and 20% of polyunsaturated fatty acids with about 8% of docosahexaenoic acid. Atherogenic and thrombogenic indices were 0.58 and 0.42, respectively. Both n6/n3 and polyunsaturated/saturated fatty acids ratios were in accordance with value recommended for a healthy nutrition giving positive evaluation of the nutritional qualities of tench.

Validation of a Recombinant Based Antibody ELISA for Diagnosis of Human and Canine Leishmaniasis

Abstract In this study, a recombinant chimeric antigen (CA) ELISA was validated as a single test for both human and dog leishmaniasis. Serum panels included 327 human and 339 canine IFAT-positive and 1113 human and 1078 canine IFAT-negative samples. CA-ELISA was carried out using the same serum dilution, and labelled protein A as secondary reagent. Test performances were calculated using ROC analysis. For the human panel, the test showed diagnostic accuracy (DA) 0.974, specificity (Sp) 97.12%, sensitivity (Se) 91.44%, and concordance (K) 0.88. The dog panel showed DA 0.998, Sp 99.54%, Se 98.54%, and K 0.98. The proposed method is the best recombinant antigen-based ELISA, and can be used as IFAT substitute for mass screening.

Alternative Dietary Sources in Feeding of Blackspot Sea Bream Pagellus bogaraveo (Brunnich, 1768)

The present review reports the results of two studies carried out at the Institute for the Coastal Marine Environment of Messina (Italy) on the suitability of plant-derived raw materials as dietary components for an innovative fish species for aquaculture, black spot sea bream Pagellus bogaraveo. The research focused on the effects of the use of plant (protein/lipid) dietary sources on growth performance, body composition and gastro-intestinal enzyme patterns in nutrient digestion of wild juveniles of P. bogaraveo. In particular, the effect of a total replacement of Fish oil by Echium and linseed oils and a partial substitution of fish meal with a graded level of Rice Protein Concentrate, will be discussed.

Artificial pigmentation and flesh quality in red porgy (Pagrus pagrus)

Red porgy (Pagrus pagrus) is a highly valued species of increasing interest for the Mediterranean aquaculture, characterized by a natural red-pink skin coloration, which acquires a gray color under culture conditions. This study was carried out in order to define new diets to modify the pigmentation variability of the red porgy skin. Six thousand red porgy juveniles (29.21 ± 6.39 g) were randomly distributed in three tanks with a volume of 55 m3 each and fed for 8 months with three extruded diets supplemented with graded levels of synthetic carotenoids (GFP0, GFP30, and GFP60). Color, carotenoid content, fatty acid composition of fish skin, chemical and fatty acid composition of fish flesh, and digestive enzymes and histological analysis of the intestine and liver of the fish were determined. The results showed that the supplementation of the synthetic carotenoids affected significantly the skin color indexes with the higher values of redness, yellowness, and chroma recorded in the fish fed with the GFP60 diet, while the other parameters investigated were unaffected except the intestinal protease activities of the GFP60 group, which had lower results. The present study showed encouraging results for developing a new research, but they are not satisfying to the application of this carotenoid supplement feed for this species in production farming.

Use of rice protein concentrate in rainbow trout feeding: preliminary results

Riassunto Impiego di un concentrato proteico di riso nell’alimentazione della trota iridea: risultati preliminari. E’ stato valutato l’effetto di un concentrato proteico di riso (RPC) in parziale sostituzione alla farina di pesce sulle prestazioni zootecniche di trota iridea. Dopo 94 giorni di alimentazione sono stati rilevati i parametri produttivi e gli indici somatici. Alla fine della prova sono emerse differenze significative per quanto attiene l’incremento in peso, l’indice di conversione alimentare, il tasso di accrescimento specifico e l’efficienza proteica. Relativamente agli indici somatici, si sono evidenziate differenze statisticamente significative a carico dell’indice viscerosomatico e del coefficiente di adiposità.