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- Effects of dietary curcumin in growth performance, oxidative status and gut morphometry and function of gilthead seabream postlarvaePublication . Xavier, Maria João; Navarro-Guillén, Carmen; Lopes, André; Colen, R.; Teodósio, Rita; Mendes, Rodrigo; Oliveira, Beatriz; Valente, Luisa M.P.; Conceição, Luís E.C.; Engrola, SofiaAn imbalance in the production and detoxification of reactive oxygen species and other oxidants can disrupt a l l types of cellular compounds, and lead to a state of oxidative stress. Preventing this state is essential to improve growth and health in animal production. Therefore, the aim of this work was to assess i f the dieta r y supple-mentation of curcumin cou l d improve the antioxidant status and intestine structu r e and functionalit y of gilthead seabream postlarvae, with the global objective of improving fish growth performance and robustness. Two experimental diets supplemented with different doses of curcumin (LOW and HIGH diets), and a commercial diet were fed to quadruplicate groups of postlarvae, for 20 days. At the end of the feeding trial fish fed the supple-mented diets significantly improved their antioxidant status compared to CTRL fed fish. LOW and HIGH fed fish presented lower protein oxidative damage (P < 0.05) and higher total antioxidant capacity (P < 0.05). Moreover, postlarvae fed curcumin supplemented diets also presented an upregulation of nuclear factor erythroid 2 - related factor 2 (nrf2) and glutathione-disulfide reductase (gr) in HIGH (P < 0.05) and heat shock protein 70 (hsp70) in LOW treatments (P < 0.05). No differences were observed in growth performance, intestine morphome t r y , and digestive enzymes activities among treatments (P > 0.05). In conclusion, dieta r y curcumin supplementation was able to enhance gilthead seabream postlarvae robustness through a modulation of the oxidative status, increasing total antioxidant capacity and decreasing protein oxidative damage. This data pro-vide evidence that curcumin can be a suitable feed additive to promote heath status and robustness of fish at early stages of development, therefore contributing for the development and sustainabilit y of marine fish hatchery production.
- Development and application of a mechanistic nutrient-based model for precision fish farmingPublication . Soares, Filipe M. R. C.; Nobre, Ana M. D.; Raposo, Andreia I. G.; Mendes, Rodrigo; Engrola, Sofia; Rema, Paulo J. A. P.; Conceição, Luís E. C.; Silva, Tomé S.This manuscript describes and evaluates the FEEDNETICS model, a detailed mechanistic nutrient-based model that has been developed to be used as a data interpretation and decisionsupport tool by fish farmers, aquafeed producers, aquaculture consultants and researchers. The modelling framework comprises two main components: (i) fish model, that simulates at the individual level the fish growth, composition, and nutrient utilization, following basic physical principles and prior information on the organization and control of biochemical/metabolic processes; and (ii) farm model, that upscales all information to the population level. The model was calibrated and validated for five commercially relevant farmed fish species, i.e., gilthead seabream (Sparus aurata), European seabass (Dicentrarchus labrax), Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), and Nile tilapia (Oreochromis niloticus), using data sets covering a wide range of rearing and feeding conditions. The results of the validation of the model for fish growth are consistent between species, presenting a mean absolute percentage error (MAPE) between 11.7 and 13.8%. Several uses cases are presented, illustrating how this tool can be used to complement experimental trial design and interpretation, and to evaluate nutritional and environmental effects at the farm level. FEEDNETICS provides a means of transforming data into useful information, thus contributing to more efficient fish farming
- ficoEst – a tool to estimate the body composition of farmed fishPublication . Soares, Filipe; Raposo, Andreia; Mendes, Rodrigo; Azevedo, Marina; Dias, Deborah; Nobre, Ana; Conceição, Luís E. C.; Silva, ToméficoEst - Fish Composition Estimator is a public web tool to estimate the whole-body proximate composition of farmed fish (https://webtools.sparos.pt/ficoest/). The tool was designed for researchers in fish nutrition and fish farmers, and is available for six commercially relevant species: gilthead seabream (Sparus aurata), European seabass (Dicentrarchus labrax), meagre (Argyrosomus regius), rainbow trout (Onchorhynchus mykiss), Atlantic salmon (Salmo salar), and Nile tilapia (Oreochromis niloticus). ficoEst uses three different types of mathematical models (BC1, BC2, and BC3) to estimate the body composition of fish in terms of crude protein, crude lipids, water, ash, phosphorus, and energy. The models differ in the input data used to perform the estimates. BC1 models consider only body weight, BC2 models consider both body weight and water, and BC3 models consider body weight, water, and ash as inputs. The model evaluation results demonstrate that considering water and ash as additional inputs to body weight (BC3 models) significantly improves the accuracy in predicting some body composition components, such as crude lipids (e.g., up to 67.9 % and 28.1 % more accurate, compared to BC1 and BC2 models, respectively, depending on the species considered). ficoEst can be used as a complementary tool to analytical methods to obtain additional information about fish body composition. As a public web tool, ficoEst has the potential to be a valuable resource for researchers and fish farmers interested in estimating the body composition of farmed fish.
- Nile tilapia and gilthead seabream dietary self-selection of alternative feedsPublication . Luís E. C. Conceição; Jorge Dias; Mendes, Rodrigo; Engrola, Sofia; Engrola, SofiaClassical assessments of new fsh feeds are anthropocentric, focusing mainly on growth. Although this methodology is accurate, it does not consider the fsh’ perspective. This study aimed to investigate the behavioural responses and feed preferences of Nile tilapia (Oreochromis niloticus) and gilthead seabream (Sparus aurata) through a self-selection trial using self-feeders. Both species were ofered three feeds: a control (PD) commercial-like feed and two diets (ORG1 and ORG2) formulated with diferent inclusions of alternative ingredients to address some of the current environmental concerns and/ or ethical issues often associated with commercial formulations. Three groups of tilapia with an average weight of 163.0 g±4.3 g (mean±SD) and four groups of seabreams with 174.7 g±27.0 g were tested. Tilapia exhibited a preference for ORG2 (46.5%), infuenced by the sensory properties of the feed and post-ingestion signals. Seabream did not show a preference for any feed. These fndings highlight the efectiveness of self-selection experiments in allowing fsh to express their feeding behaviour and preferences. Therefore, this approach should be considered in the initial screening and design of new aquaculture feeds and ingredients.
- Socially acceptable feed formulations may impact the voluntary feed intake and growth, but not robustness of Nile Tilapia (Oreochromis niloticus)Publication . Mendes, Rodrigo; Rena, Paulo; Dias, Jorge; Fachadas Gato Coelho Gonçalves, Ana Teresa; Teodósio, Rita; Engrola, Sofia; Sánchez-Vázquez, Francisco J.; Conceição, Luís E. C.Society is becoming more demanding with aquaculture’s environmental footprint and animal wellbeing. In order to potentially mitigate these concerns, feed formulations could be based on eco-efficient (circular economy-driven) or organic ingredients. This study aimed to investigate the growth performance, feed utilization, and health status of juvenile Nile tilapia (Oreochromis niloticus) when fed with such feeds. The growth trial lasted for 8 weeks, and fish had an initial weight of 31.0 ± 0.5 g (mean ± SD). Fish were fed until visual satiation, in quadruplicate, with one of three isonitrogenous and isoenergetic experimental feeds: a commercial-like feed without fishmeal (PD), a diet based on ingredients compatible with organic certification (ORG), or a feed formulated using circular economy-driven subproducts and emergent ingredients (ECO). Fish fed ECO showed a tendency for decreased feed intake, while ORG fish significantly reduced their intake compared to those fed PD. Consequently, fish fed ECO (62.7 ± 5.4 g) exhibited almost half the growth than those fed PD (107.8 ± 6.1 g), while ORG fish almost did not increase their weight (32.7 ± 1.3 g). ECO and ORG diets had a lower digestibility for protein, lipid, and energy when compared to PD. Feed utilization of fish fed ECO or ORG was also lower than those fed PD. From the health-related genes analyzed, only glutathione reductase (gsr) showed statistically significant differences, being more expressed in fish-fed ECO than those fed PD. Thus, even when such novel formulations induced extreme effects on voluntary feed intake, their impact was noted only in fish growth, but not in robustness.