Journal: |
Egyptian Journal of Aquatic Biology & Fisheries
Scopus
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Volume: |
28
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Abstract: |
Finding suitable alternatives to animal protein used in the manufacture of
fish feed is one of the major challenges at present since these alternatives must be
sustainable, with an abundance in nature, available and easy to obtain, and
economically inexpensive. The goal of this study was to investigate how the gradual
replacement of fishmeal with dried zooplankton (DZ) affected gilthead seabream
(Sparus aurata) larvae over a four-month experiment. Nine hundred fish were
allocated into five groups with an initial average weight of 0.227± 0.030g. The fish
were fed five isonitrogenous and isocaloric diets in which fish meal was replaced by
dried zooplankton (DZ) at different levels: 0 (G1), 25 (G2), 50 (G3), 75 (G4), and
100% (G5). The effects of diets on growth performance, feed utilization, survival,
and body composition were tested. The results showed that substituting dried
zooplankton for fishmeal had a strong relationship with fish weight gain, length
gain, and feed conversion ratio, with R2 values of 0.99, 0.94, and 0.97, respectively.
The polynomial regression model, which exhibited the maximum response at G4
and G5, was determined to be the most suitable regression model to reflect the fish's
reaction to the replacement of fish meal with dried zooplankton (DZ). Using dried
zooplankton (DZ) instead of fish meal (FM) in the early stages of gilthead seabream
feeding proved to be an excellent strategy for enhancing growth and reducing
mortality rates by 50%. The 75% replacement rate showed the best results in terms
of lowering mortality, while both the 75 and 100% replacement rates were optimal
for growth criteria. In summary, this study found that a complete substitution of fish
meal with dry zooplankton meal in gilthead seabream diets was achievable without
adverse impacts on weight development, length growth, or feed utilization.
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