Growth Performances of Tilapia (Oreochromis niloticus) Fed with Duckweed (Lemna minor)
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Date
2020
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Publisher
Uva Wellassa University of Sri Lanka
Abstract
Food fish is the most valuable protein source and highly enriched with many nutrients.
The cost of feed is the major reason for decreasing food fish production. The present
study was conducted to identify the effect of duckweed on the growth of Tilapia. Five
different diets (experiment, 2, 3, 4, 5, 6) were prepared with 40% crude protein while
control diet. Experiment 1 contained a 0% duckweed leaf meal. Fish meal in experiment
2-5 was partially replaced with 10, 20, 30, 40, and 50% of dried duckweed leaf meal.
Tilapia fry (bodyweight 0.21± 0.007 g and standard length 0.73± 0.005 cm) reared in
indoor glass tanks were used for each experiment's diets ensuring three replicates. Daily
feed allowance (5% of body weight of fish) was offered at 0900 h. and 1500 h. Results
showed that mean weight gain recorded in fish fed with the experimental diets 2, 3, 4, 5,
and 6 were significantly different from that of fish fed with the control diet (p< 0.05).
There was a significant difference in the Specific Growth Rate of fish fed with the control
diet and the experimental diets. Survival Rate of the fish fed with the experimental diets
2, 3, 4 was not significantly different (p> 0.05) with a control diet, when diet 5 and 6 were
significantly different (p<0.05) with a control diet at the end of the study period. The
highest Feed Conversion Ratio was recorded in fish fed with a control diet (1.28) and the
lowest ratio was recorded in diet 4 (0.98). Protein Efficiency Ratio of fish fed with every
5 experimental diets were significantly different from the control diet (p<0.05) at the end
of the study period. The cost of production for 1 kg of feed was considerably low for diet
6 compared to the control diet. Present results showed that 30% of dried duckweed leaf
meal in a formulated diet for Nile Tilapia fish is very effective and showed the highest
growth rate.
Keywords: Oreochromis niloticus, Duckweed, Crude protein, Growth performance, Fish
feed
Description
Keywords
Aquaculture and Fisheries, Aquaculture, Food Science, Animal Sciences