Influence of diet and feeding strategy on the performance of nitrifying trickling filter,oxygen consumption and ammonia excretion of gilthead sea bream (Sparus aurata) raised in recirculating aquaculture systems     

Godoy-Olmos  Sergio  Jauralde  Ignacio  Monge-Ortiz  Raquel  Milián-Sorribes  María C.  Jover-Cerdá  Miguel  Tomás-Vidal  Ana  Martínez-Llorens  Silvia 《Aquaculture International》2022,30(2):581-606

Gilthead sea bream (Sparus aurata) was raised in six individual recirculating aquaculture systems (RAS) whose biofilters’ performance was analyzed. Fish were fed with three different diets (a control diet, a fishmeal-based diet (FM), and a plant meal-based diet (VM)) and with three different feeding strategies (manual feeding to apparent satiation, automatic feeding with restricted ration, and auto-demand feeding). For every combination of diet and feeding strategy, the mean oxygen consumption, ammonia excretion, and ammonia removal rate were determined. Fish fed with the VM diet consumed the most oxygen (20.06?±?1.80 gO₂ consumed kg^?1 day^?1). There were significant differences in ammonia excretion depending on the protein content and protein efficiency of the diet, as well as depending on feeding strategy, which in turn affected ammonia removal rates. Fish fed by auto-demand feeders led to the highest mean ammonia removal rate (0.10 gN-TAN removed m^?2 biofiltration area day^?1), while not leading to peaks of high ammonia concentration in water, which preserve fish welfare and growth.

  相似文献   

A proposal for modelling the thermal‐unit growth coefficient and feed conversion ratio as functions of feeding rate for gilthead sea bream (Sparus aurata,L.) in summer conditions     

Ignacio Jauralde  Silvia Martínez‐Llorens  Ana Tomás  Rodolfo Ballestrazzi  Miguel Jover 《Aquaculture Research》2013,44(2):242-253

Modelling growth as a function of feeding rate (FR) could be one of the most important tools for fish farms, because this knowledge allows growth to be maximized, or the feed conversion ratio (FCR) to be minimized, thereby improving profits. All growth models should include the three principal variables involved in growth: initial body weight, temperature and feeding rate. The thermal‐unit growth coefficient (TGC) already includes water temperature variation and initial body weight. Studying variation in TGC for fish fed the same diet, but at several feeding rates provides interesting information for modelling. Six different trials were conducted where gilthead sea bream of several different initial weights (24, 38, 50, 110, 220 or 289 g) were fed increasing amounts, and growth and the conversion index response were measured. The TGC response was modelled as a function of FR, and both asymptotic and quadratic responses were examined. The asymptotic model, TGC × 1000 = 2.037*(1?e ^{(?0.8*(FR?0.22)}), had an adjusted R² value of 96.18, whereas the quadratic model, TGC × 1000 = ?0.381 + 1,715 × FR?0,382 × FR², had an adjusted R² value of 96.42. Simulations of the FCR and the economical profitability index (EPI) were conducted to provide tools for maximizing efficiency and profitability, and the results suggest that these tools will be useful for future investigations.  相似文献