Different stocking densities of tilapia fingerlings in BFT system on parameters of water quality and production performance
摘要
The objective of this study was to assess how different stocking densities affect water quality in a biofloc system (BFT), as well as the growth performance, and the intestinal, hepatic, and muscular physiology of Nile tilapia fingerlings. The experimental design evaluated four levels of stocking densities—375, 750, 1125, and 1500 fish m−3—in the BFT system, using tilapia fingerlings with an average weight of 12.9 ± 0.15 g. The stocking densities of 375 and 750 fish m−3 promoted the best growth performance, as measured by weight gain (WG), daily weight gain (DWG), protein efficiency rate (PER), specific growth rate (SGR), apparent feed conversion (FC), and the survival rate (SUR). Somatic indices and intestinal development parameters showed no significant variation across the different stocking densities. The histomorphometry of the midgut and liver revealed no changes across the different stocking densities. At a stocking density of 750 fish m−3, an increase in muscle fiber suggests cellular hyperplasia, particularly in the fiber size class below 15 µm. Water quality parameters, the levels of suspended solids, ammonia, nitrite, and the inclusion of a carbon source in the water recorded the lowest levels at a density of 375 fish m−3. The proximate composition of the BFT at the start and end of the cultivation period remained unchanged, including moisture, crude protein, mineral content, and fiber levels. Thus, a stocking density of 750 fish m−3 ensures optimal growth performance while maintaining tilapia fingerling cultivation fish physiology and water quality within acceptable limits for BFT cultivation.