In vivo total nitrogen and total phosphorous digestibility in Atlantic Bluefin Tuna (Thunnus thynnus thynnus Linnaeus, 1758) under industrially intensive fattening conditions in Southeast Spain Mediterranean coastal waters

摘要: Atlantic Bluefin Tuna (hereafter referred to as tuna) fattening has been developed quite a lot in south-eastern Spanish Mediterranean coastal waters, but previous information about nutrition and environmental impact is scarce. Total nitrogen total phosphorous digestibility was investigated tuna under routine operation conditions first step know nutrient utilization provide tools for estimation of waste output. Tunas were fed ad libitum once day with mixture mackerel, herring, pilchard gilt-sardine. Body weight sampled ranged between 150 350 kg. Faeces collected by dissection the distal intestine after slaughtering directly manual sieve scuba divers into sea cages. Endogenous inert marker acid insoluble ash. Apparent coefficient (ADC) total-N lower when faeces (DI: 658.2 g kg-1) than direct collection (DC: 937.4 kg-1). Total-P ADC 481.4 661.9 The high other carnivorous fish, while low digestibility, many fishes, could be related excess diet. DC results seem more consistent appropriate output estimation. Results demonstrate need accurate nutritional evaluation development formulated artificial diets.