No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
ResearchGate has not been able to resolve any citations for this publication.
In the present study, the experiments were conducted during the period from June to October 2019 (20-weeks) to evaluate the effect of Biofloc technology (BFT) on mono sex Nile tilapia, Oreochromis niloticus fingerlings. It was focused on water quality, growth parameters, hepatosomatic index (HIS), spleenosomatic index (SSI), Hematology and biochemistry. Triplicated treatments were designed, two Biofloc treatments with two fish densities (12 &16 fish/200 L tank) vas two control groups. All treatments were fed with 3% of body weight in two equal divided meals. Rice brane and Molasse (1:1) were added as a carbon source to Biofloc treatments twice daily after one hour of main meals.
Results indicated that total ammonia-N and Nitrite-N were significantly decreased at Biofloc treatments. Biofloc treatments showed significantly high average final body weight, better feed conversion ratio (FCR) and one ninth water consumption. Biofloc addition had generally no significant difference of hematology, biochemistry and hepatosomatic index (HSI), while spleenosomatic index (SSI) was significantly increased at high density only. It could be concluded that Biofloc treatments improve water parameters stability and fish growth performance while it decreased water consumption. High density (16 fish/200 L) is more yield productive treatment.
Aquaculture intensification is characterized by high stocking density and need of high quality and quantity of artificial feed. Increased fish biomass and feed input brings about rapid deterioration of water quality hence a water quality management system need to be put in place in such systems. Biofloc technology has been developed as a viable option to recycle nutrient by maintaining a high carbon/nitrogen (C/N) ratio in the water in order to stimulate heterotrophic bacterial growth which converts ammonia into useful microbial biomass. This study investigated the effect of carbon source supplement in biofloc system on growth performance, water quality and microbial community in the system. The experimental research was conducted at the University of Eldoret from June-September 2017. A complete randomized design was used in triplicate treatments. The supplementation carbon source constituted molasses, wheat flour, potatoes flour and control respectively. At molasses carbon added treatments Nile tilapia indicated the highest significant growth at (p < 0.05) than other treatments with final mean weights (8.774±0.394g) and total length (7.956±0.123cm). The least growth of Nile tilapia fingerlings was at control treatments with final mean (3.784±0215g, 5.827±0.114cm) weights and length respectively. Molasses added bioflocexhibited highest protozoan (520.13±1.02), rotifers (200.6±1.08), cyanobacteria (143.1±1.22) and diatoms (60.033±0.083) and improved water quality as compared to other treatments. The results revealed that molasses added in biofloc system improves Nile tilapia growth, microorganism colonization and water quality in the system than other carbon added treatment tested. The study recommends molasses carbon source for Nile tilapia fingerlings growth as it pertaining to the improved results of microorganism levels and water quality obtained in the system.
Controlling the inorganic nitrogen by manipulating the carbon/nitrogen ratios is a potential control method for aquaculture systems. This approach seems to be a practical and inexpensive means of reducing the accumulation of inorganic nitrogen in the pond. Nitrogen control is induced by feeding bacteria with carbohydrates, and through the subsequent uptake of nitrogen from the water, by the synthesis of microbial proteins. The relationship among the addition of carbohydrates, the reduction of ammonium and the production of microbial proteins depends on the microbial conversion coefficient, the C/N ratio in the microbial biomass, and the carbon contents of the added material. The addition of carbonaceous substrate was found to reduce inorganic nitrogen in shrimp experimental tanks and in tilapia commercial-scale ponds. It was found in tilapia ponds that the produced microbial proteins are taken up by the fish. Thus, part of the feed protein is replaced and feeding costs are reduced. The addition of carbohydrates, or the equivalent reduction of proteins in the feed, can be quantitatively calculated and optimised, as shown here. Approximate parameters were used in this work. Additional research in this field should be directed at gathering the precise data needed for the exact planning of feed composition.
In the present study, the experiments were conducted during the period
from June to October 2019 (20-weeks) to evaluate the effect of Biofloc
technology (BFT) on mono sex Nile tilapia, Oreochromis
niloticus fingerlings. It was focused on water quality, growth parameters,
hepatosomatic index (HIS), spleenosomatic index (SSI), Hematology, and
biochemistry. Triplicated treatments were designed, two Biofloc treatments
with two fish densities (12 &16 fish/200 L tank) vas two control groups. All
treatments were fed with 3% of body weight in two equally divided meals.
Rice brane and Molasse (1:1) were added as a carbon source to Biofloc
treatments twice daily after one hour of main meals. Results indicated that
total ammonia-N and Nitrite-N were significantly decreased at Biofloc
treatments. Biofloc treatments showed significantly high average final body
weight, better feed conversion ratio (FCR), and one-ninth water consumption.
Biofloc addition had generally no significant difference of hematology,
biochemistry, and hepatosomatic index (HSI), while spleenosomatic index
(SSI) was significantly increased at high density only. It could be concluded
that Biofloc treatments improve water parameters stability and fish growth
performance while it decreased water consumption. High density (16 fish/200
L) is a more yield productive treatment.
The State of World Fisheries and Aquaculture; c2022
- Anonymous
Anonymous. The State of World Fisheries and
Aquaculture; c2022.
https://www.fao.org/3/cc0463en/cc0463en.pdf accessed
on 24th March 2024.