Optimization of feeding rate for hatchery-produced
juvenile gilthead sea bream Sparus aurata
A.
Mihelakakis, C. Tsolkas, T. Yoshimatsu-2002
Journal
of the World Aquaculture Society, 33(2): 169-175 (from Current Contents)
Abstract:
A
61-d growth trial (five 11-d feeding periods) was conducted to determine the
effects of feeding rate on growth, feed utilization, morphology, and body
composition of the gilthead sea bream Sparus aurata. Gilthead sea bream
juveniles with an average initial body weight of 3 g were fed a commercial
diet (51% crude protein, 11% crude fat) at rates of 0.5, 1.0, 1.5, 2.0, 2.5,
or 3.0% of their body weight (BW) per day in two equal meals. Water
temperature was approximately 21.4°C throughout the experiment. Each ration
was administered to triplicate groups of 60 fish, with ration readjusted
every 11 d. Growth rate was measured as specific growth rate (SGR). Survival
rate and coefficient of variation did not differ significantly among the
groups fed different rates. Body weight, condition factor, and hepatosomatic
and viscerosomatic indices displayed significant increases with increasing
feeding rate from 0.5 to 3.0% BW/d. Fish fed 0.5% BW/d had significantly
higher moisture and ash and lower protein contents than those fed at higher
rates. Moisture and protein contents were not significantly different for
fish fed at the highest feeding rates (2.0, 2.5, and 3.0% BW/d). Lipid
contents increased significantly with increasing feeding rate from 0.5 to
3.0% BW/d. The SGR showed a curvilinear significant increase when the
feeding rate was increased from 0.5 to 3.0% BW/d. Feed efficiency (FE)
increased significantly to a maximum value with increasing feeding rate from
0.5 to 2.0% BW/d and decreased significantly with increasing feeding rate
from 2.5 to 3.0% BW/d. Based on the data obtained, feeding rates of 2.3% and
0.6% BW/d are recommended as optimum and maintenance rations, respectively.
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