Abou-Seif, R. (2006). EFFECTS OF STOCKING DENSITY AND PROTEIN LEVEL IN DIET ON GROWTH PERFORMANCE, SURVIVAL RATE AND FEED EFFICIENCY OF NILE TILAPIA (OREOCHROMIS NILOTICUS L.) FRY MONOSEX DURING THE NURSERY PERIOD.. Egyptian Journal of Aquatic Biology and Fisheries, 10(3), 69-84. doi: 10.21608/ejabf.2006.1863
Ramadan Abou-Seif. "EFFECTS OF STOCKING DENSITY AND PROTEIN LEVEL IN DIET ON GROWTH PERFORMANCE, SURVIVAL RATE AND FEED EFFICIENCY OF NILE TILAPIA (OREOCHROMIS NILOTICUS L.) FRY MONOSEX DURING THE NURSERY PERIOD.". Egyptian Journal of Aquatic Biology and Fisheries, 10, 3, 2006, 69-84. doi: 10.21608/ejabf.2006.1863
Abou-Seif, R. (2006). 'EFFECTS OF STOCKING DENSITY AND PROTEIN LEVEL IN DIET ON GROWTH PERFORMANCE, SURVIVAL RATE AND FEED EFFICIENCY OF NILE TILAPIA (OREOCHROMIS NILOTICUS L.) FRY MONOSEX DURING THE NURSERY PERIOD.', Egyptian Journal of Aquatic Biology and Fisheries, 10(3), pp. 69-84. doi: 10.21608/ejabf.2006.1863
Abou-Seif, R. EFFECTS OF STOCKING DENSITY AND PROTEIN LEVEL IN DIET ON GROWTH PERFORMANCE, SURVIVAL RATE AND FEED EFFICIENCY OF NILE TILAPIA (OREOCHROMIS NILOTICUS L.) FRY MONOSEX DURING THE NURSERY PERIOD.. Egyptian Journal of Aquatic Biology and Fisheries, 2006; 10(3): 69-84. doi: 10.21608/ejabf.2006.1863
EFFECTS OF STOCKING DENSITY AND PROTEIN LEVEL IN DIET ON GROWTH PERFORMANCE, SURVIVAL RATE AND FEED EFFICIENCY OF NILE TILAPIA (OREOCHROMIS NILOTICUS L.) FRY MONOSEX DURING THE NURSERY PERIOD.
Central Lab. For Aquaculture Research, Abbassa, Abou- Hammad, Sharkia Governorate, Egypt.
Abstract
The effects of stocking density and dietary protein levels on growth performance, larval survival and feed utilization efficiency of Nile tilapia (O. niloticus L.) fiy monosex (0.014 g average initial body weight) were investigated in a single-stage nursery-rearing system using 1389 and 2778 hatchlings/ m3 as stocking densities within each density 29.71, 34.43 and 39.11% dietary protein levels. Twelve fiberglass tanks (180 liter volume for each) on a flow- through system (100%/day)were used to represent the two stocking densities and the three protein levels in replicates. The dietary treatments were fed 7 days/week (twice daily) at a rate of 15% of the total biomass during the 1st 45-days then reduced to 10% of total biomass from days 46 to 75, after that it was reduced to 5% of total biomass till the end of the experiment (105 days).The results revealed that there was significant increase (P< 0,01) in growth rate with decreasing stocking density and increasing dietary protein level during all experimental periods. The same trend was also observed for mean body weight (g), specific growth rate (SGR%/day), condition factor (k) and survival rate (SR %). The best final mean body weight (g), SGR, K and (SR %) were recorded in groups of fish stocked in 1389 hatchlings /m3 and fed on the diet containing 39.11% CP)(T3SR1).The effects of stocking density and dietary protein levels on growth performance, larval survival and feed utilization efficiency of Nile tilapia (O. niloticus L.) fiy monosex (0.014 g average initial body weight) were investigated in a single-stage nursery-rearing system using 1389 and 2778 hatchlings/ m3 as stocking densities within each density 29.71, 34.43 and 39.11% dietary protein levels. Twelve fiberglass tanks (180 liter volume for each) on a flow- through system (100%/day)were used to represent the two stocking densities and the three protein levels in replicates. The dietary treatments were fed 7 days/week (twice daily) at a rate of 15% of the total biomass during the 1st 45-days then reduced to 10% of total biomass from days 46 to 75, after that it was reduced to 5% of total biomass till the end of the experiment (105 days).The results revealed that there was significant increase (P< 0,01) in growth rate with decreasing stocking density and increasing dietary protein level during all experimental periods. The same trend was also observed for mean body weight (g), specific growth rate (SGR%/day), condition factor (k) and survival rate (SR %). The best final mean body weight (g), SGR, K and (SR %) were recorded in groups of fish stocked in 1389 hatchlings /m3 and fed on the diet containing 39.11% CP)(T3SR1).