The effects of dietary lipid and fibre levels on digestibility of diet and on the growth performance of sharpsnout seabream (Diplodus puntazzo)

In the present study, sharpsnout seabream (Diplodus puntazzo) were fed three experimental isonitrogenous diets composed of 45 g 100g-1 protein and varying lipid and fibre contents as follows: diet A: 45/10/1.5, B: 45/15/1.5 and C: 45/15/5. The effects of the diet composition were investigated by measuring digestibility, growth, carcass composition and haematological parameters. The apparent digestibility coefficients (ADCs) for proteins, fats and carbohydrates, measured at high (26˚C) and low (16˚C) water temperatures in laboratory conditions, were not affected by the diet or temperature treatments. Growth was evaluated in a seven-month trial using animals held in sea cages. The specific growth rate (SGR) showed no significant differences among the treatments while the feed conversion ratio (FCR) was significantly improved in the fish that were fed a low-fat diet. A significant increase in body fat was detected in the fish that were fed high-fat diets. The blood serum total lipid levels were elevated for the fish that were fed diet C. In conclusion, a diet containing a protein/fat/fibre ratio of 45/10/1.5 g 100g-1 can result in satisfactory growth and an improved FCR value when compared with diets with higher fat and/or fibre levels, demonstrating that the required fat level for sharpsnout seabream is lower than 15 g 100g-1

Feed and nutrition in organic aquaculture

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Effects of novel ingredients on growth performance in european sea bass, dicentrarchus labrax

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Post-prandial amino acid changes in gilthead sea bream

Following a meal, a series of physiological changes occurs in fish as they digest, absorb and assimilate ingested nutrients. This study aims to assess post-prandial free amino acid (FAA) activity in gilthead sea bream consuming a partial marine protein (fishmeal) replacement. Sea bream were fed diets where 16 and 27% of the fishmeal protein was replaced by plant protein. The essential amino acid (EAA) composition of the white muscle, liver and gut of sea bream was strongly correlated with the EAA composition of the 16% protein replacement diet compared to the 27% protein replacement diet. The mean FAA concentration in the white muscle and liver changed at 4 to 8 h after a meal and was not different to pre-feeding (0 h) and at 24 h after feeding. It was confirmed in this study that 16% replacement of marine protein with plant protein meets the amino acid needs of sea bream. Overall, the present study contributes towards understanding post-prandial amino acid profiles during uptake, tissue assimilation and immediate metabolic processing of amino acids in sea bream consuming a partial marine protein replacement. This study suggests the need to further investigate the magnitude of the post-prandial tissue-specific amino acid activity in relation to species-specific abilities to regulate metabolism due to dietary nutrient utilization

Antibacterial drugs in products originating from aquaculture: assessing the risks to public welfare

As aquaculture expands to meet human demand and compensate for pessimistic forecasts of fisheries catches, use of antibacterial agents to combat or forestall bacterial diseases is still a necessity, although effective vaccines and improved hygiene have aided drastically in this battle. The hazards for the consumer perspective arising from the imprudent use of such chemicals can be detrimental, especially if the residues persist above legal tolerance. These may include selection and dissemination of resistant bacteria, disruption of the colonization barrier in the human intestinal flora and allergic reactions. In cases that unlawful drugs reached the consumer via consumption of aquatic products, human health may be jeopardized even further. The present review article assesses these risks to human health