Browsing by Author "Shabani, Salimu"
Now showing 1 - 2 of 2
- Results Per Page
- Sort Options
Item Effects of inorganic fertilizer application and supplementary feeding on water physico-chemical parameters, growth performance and yield of Nile Tilapia (Oreochromis niloticus) cultured in earthen ponds(International Journal of Fisheries and Aquatic Research, 2020) Shabani, Salimu; Munubi, Renalda N; Chenyambuga, Sebastian W; Madalla, Nazael A.; Quagrainie, Kwamena; Frimpong, Emmanuel; Egna, HillaryThis study was carried out for 180 days to assess the growth performance, water physico-chemical parameters, yield and profitability of Nile tilapia (Oreochromis niloticus) culture in earthen ponds. The fish were reared in nine earthen ponds with average size of 177 m 2 and subjected to three treatments i.e. pond fertilization alone (T 1 ), concentrate feeding alone (T 2 ) and a combination of pond fertilization plus concentrate feeding (T 3 ). Sex- reversed Nile tilapia fingerlings were stocked at a density of 3 fish/m 2 . For T 1 and T 3 , urea and Diammonium phosphate (DAP) fertilizers were applied in pond water weekly at a rate of 3 g/m 2 and 2 g/m 2 , respectively. For T 2 and T 3 the fish were fed a diet containing 25.1% crude protein (CP) at a rate of 5% and 2.5% of body weight, respectively. Pond water physico-chemical parameters were measured weekly. A total of 30 fish from each pond were harvested biweekly and individually measured for body weight and length. Dissolved oxygen (DO), pH, Secchi disk reading, conductivity, salinity, phosphorous, nitrate and alkalinity differed (p ≤ 0.05) but temperature did not differ (p > 0.05) among treatments. In all treatments the water quality parameters were within the acceptable range for tilapia culture. Within a 24 hours period, DO, pH and temperature were highest at 1500 hours and lowest at 0600 hours. The fish reared under T 3 showed higher (p < 0.05) body weight gain (194.1 ± 4.5 g), growth rate (GR) (1.5 ± 0.1 g/day), estimated yield (13 065 ± 458 kg/ha/year) and gross margin (12 364.41 ± 1 376.75 USD/ha) than those under the other treatments. The FCR was higher (4.1 ± 0.3) for the fish subjected to T 2 and lower (2.0 ± 0.1) for the fish reared under T 3 . The highest condition factor (K) (2.54 ± 0.0) was observed for the fish reared in ponds under T 1 whereas fish under T 2 had the lowest value (2.05 ± 0.0). It is concluded that, the combination of pond fertilization plus concentrate feeding (T 3 ) is the best strategy for rearing Oreochromis niloticus, since it reduces feed utilization and results into higher growth performance and profit.Item Influence of inorganic fertilizer application and supplementary feeds on periphyton biomass, quality and species composition(International Journal of Fisheries and Aquatic Research, 2020) Shabani, Salimu; Munubi, Renalda NA study was conducted to assess the effects of fertilization alone (T 1 ), supplementary feeding alone (T 2 ) and combination of fertilization plus supplementary feeding (T 3 ) on periphyton species composition, quantity and quality. Sex-reversed Oreochromis niloticus fingerlings were stocked in earthen ponds one week after initial pond fertilization. Urea and Diammonium phosphate (DAP) fertilizers were applied in pond water at weekly intervals at a rate of 3 and 2 g/m 2 , respectively. Fish were fed feed containing 25.1% crude protein at 5% (T 2 ) and 2.5% (T 3 ) of fish body weight daily. The results show that the ponds under combination of fertilization plus supplementary feeding (T 3 ) had higher periphyton biomass (47.35 ± 7.64 g DM/m 2 ), crude protein content (11.40 ± 0.16%) and organic matter content (OM) (25.47 ± 0.28%). The periphyton from ponds under fertilization alone (T 1 ), had the highest ether extract content (1.84 ± 0.07%) and ponds treated with supplementary feeding alone (T 2 ) had higher phosphorous content (0.48 ± 0.0 mg/L). The body of fish cultured in ponds under T 3 had higher CP (69.14 ± 0.33%) and OM (96.65 ± 0.16%) contents while those reared under T 1 had higher ether extract content (18.33 ± 0.19%) and ash content (4.78 ± 0.1%), suggesting a positive relationship between algal quality and fish muscles. In addition, fish growth rate increased as the periphyton quantity (biomass and OM) and quality (CP and phosphorous) increased. The study also revealed five classes of phytoplankton (Bacillariophyceae, Chlorophyceae, Cyanophyceae, Euglenophyceae and Zygnematophyceae) and three classes of zooplankton (Eurotatoria, Heterotrichea and Oligohymenophorea). In general, both phytoplankton (algae) and zooplankton were more abundant in ponds under T 3 than in ponds under the other treatments. It is concluded that the combination of fertilization plus supplementary feeding (T 3 ) produces higher periphyton quantity, quality and species composition and thus promotes higher fish growth rate compared to feeding alone and fertilization alone treatments.