Implications of dietary Delonix regia seed meal on growth, feed utilization, haematology and fillet yield of red Nile tilapia Oreochromis niloticus

Delonix regia is commonly called Flamboyant or flame of the forest. The seeds were fermented, boiled, sundried and then ground into powdered meal. 40% crude protein based test diets containing Delonix regia seed meal D0 = 0%; D15 = 15%; D20 = 20% and D25 = 25% inclusion levels respectively were prepared. Red tilapia (Oreochromis niloticus) fingerlings of 6 weeks old were acclimatized for two weeks and then stocked in 12 hapas at 15 fish per hapa measuring 0.6 m × 1.2 m × 0.7 m placed in a concrete tank. Each diet was assigned to fish in a separate hapa in triplicate and administered at 3% fish body weight per day for 16 weeks. Fish weight and length were taken initially, bi-weekly and terminally. Water quality was monitored weekly. Number of fish at the end was recorded and survival rate, growth, feed utilization, fillet yield and blood parameters were determined. The data were subjected to the analysis of variance and mean separation (P= 0.05). Survival rate was highest in fish raised on D20 and least in D25 without any significant difference across the range. Mean growth performances, feed utilization indices and fillet yield were generally congruent between D20 and D25 with varying degrees of significant difference to other feeds. Results of blood assay did not depict harmful effects of the test diets indicating that the fish enjoyed some good measures of health. The gross performance of fish on D20 was optimal. It was therefore concluded that 20% dietary inclusion level of fermented, cooked and dried flamboyant seed was the best for the red tilapia (Oreochromis niloticus) post fingerlings.

Exotic plus native: findings in an unscheduled fish duoculture

The development of native fish aquaculture represents an important alternative to mitigate ecological displacement generated by exotic fish. The introduction of native fish in polyculture systems with high commercial value fishes has provided a useful strategy for sustainable aquaculture development. The present study aims to provide information on tilapia, as an exotic species, and Dormitator latifrons, as a native species, in a duo culture not programmed as such. Using juveniles of Pacific fat sleeper D. latifrons leftovers from another experiment, we decide to analyze and report the biological feasibility of a duoculture system with this species and Nile tilapia (Oreochromis niloticus). Two hundred fifty organisms of each species were placed for 90 days in a concrete tank with a capacity of 50 m3 to evaluate the compatibility of these species. The biological variables measured were growth, survival, feed conversion rate, and protein efficiency. The findings suggest a good interaction between species, with adequate growths and a survival rate of 98%. No antagonistic behavior was observed during confinement, suggesting the duoculture of these species may represent a good alternative for tropical sustainable aquaculture.

Concrete Tank Failure as the Result of Implementing Wrong Boundary Conditions for Wall Support—Case Study

Damage to large reinforced concrete structures is rarely due to design errors. Sometimes, however, a small error can lead to major damage and costly repairs. The article describes the damage, the results of non-destructive and destructive tests, the results of numerical calculations, and the method of repairing a reinforced concrete tank in a sewage treatment plant. The failure was caused by applying the wrong boundary conditions to the reinforced concrete wall support inside an existing biological reactor. During leak testing, one of the new walls cracked and was displaced, which resulted in the tank leaking. An inspection of wall damage and displacement was carried out on termination of the leak testing and while the tank was draining. The causes of the failure were determined based on the inventory information and numerical simulations. Both non-destructive tests of reinforcement and concrete and destructive tests of concrete were carried out. The concrete class of the foundation slab was determined based on a compression test of sample cores obtained from drilling. The aim of the non-destructive tests was to indicate the location and diameter of reinforcement in the damaged wall using electromagnetic and radar methods, as well as the location of internal defects using ultrasonic and radar methods. It was found out that the failure was a result of an incorrect determination of the anchoring length of the reinforcement. Based on the analysis, a plan to repair the damaged wall was formulated and then successfully implemented. In the article the authors proposed the IVD (identification-verification-design) scheme to make the design easier in similar cases.

Temporal analysis of the performance of an elevated concrete tank considering the corrosion of the steel reinforcement

Reinforced concrete water storage tanks are civil engineering structures subject to very aggressive atmospheric conditions that expose them to harmful corrosion risk. This dangerous phenomenon caused by the penetration of chloride ions causes pitting corrosion and leads to the reduction of the section of the reinforcements and consequently to the loss of strength and the structure performance. In this study, we are interested in analyzing the performance of an elevated storage tank, taking into account the corrosion of the reinforcements subjected to tensile stress, by considering environments with different rates of aggressiveness. A method based on Housner's model is used to evaluate the tension stresses in the reinforced concrete (RC) pedestal (supporting system) of the tank, subjected to the seismic actions. A pitting corrosion model is developed in order to determine the evolution in time of the reinforcements section in different environments. Several parameters influencing corrosion are taken into account, such as concrete cover and the concentration of chlorides ions.

Effects of nano-scale nutrients supplement on natural productivity of Thalassiosira sp. and growth performance of Pacific white shrimp, Litopenaeus vannamei, reared under intensive conditions using concrete tank culture system

ABSTRACT The aim of this study was to evaluate the use of unique mixture of nano-nutrient to extent the growth of diatom Thalassiosira sp. and the effect to the water quality, growth performance, and protein composition on the whole body of the Pacific white shrimp Litopenaeus vannamei. There are four treatments with four replicates per treatment with the use of commercial nano-nutrients (Aquaritin Aquaculture or AA) namely: (1) 0.70 mg/L; (2) 0.525 mg/L, (3) 0.35 mg/L, and (4) without any AA application, but included standard application of using urea and NPK fertilizers to enhance the growth of diatom. The use of AA was successful to trigger the growth of Thalassiosira sp. Group of shrimp treated with 0.70 mg/L had better growth rate. Results of feeding trial indicated that adding AA could also improve the biomass, final mean weight, survival, percentage weight gain, and better feed utilization in terms of FCR. The addition of AA to enhance the growth of Thalassiosira sp. also provides a beneficial impact to the protein composition in whole body of shrimp. Biologically, the protein composition in the whole body of shrimp treated with 0.7 mg/L was higher. The findings from this study showed that the addition of commercial nano-nutrient could enhance the growth of Thalassiosira sp. and led to better growth of shrimp cultured in concrete tank Key words: Growth, Litopenaeus vannamei, nano-nutrients, protein composition, Thalassiosira sp. ABSTRAK Tujuan penelitian yaitu mengevalusi penggunaan campuran unik nano-nutrien untuk meningkatkan pertumbuhan diatom Thalassiosira sp. dan pengaruhnya terhadap kualitas air, laju pertumbuhan, dan komposisi protein pada tubuh udang L. vannamei. Terdapat empat perlakuan dan empat ulangan per perlakuan dengan penggunaan nano-nutrisi komersial (Aquaritin Aquaculture atau AA) yaitu: (1) 0,70 mg/L; (2) 0,525 mg/L; (3) 0,35 mg/L, dan (4) tanpa pemberian AA, tetapi menggunakan penerapan standar pupuk urea dan NPK untuk pertumbuhan diatom. Penggunaan AA berhasil memicu pertumbuhan Thalassiosira sp. Kelompok udang yang diberi perlakuan 0,70 mg/L memiliki laju pertumbuhan yang lebih baik. Hasil uji coba pemberian pakan menunjukkan bahwa penambahan AA juga dapat meningkatkan biomassa, bobot rata-rata akhir, kelangsungan hidup, persentase pertambahan bobot dan pemanfaatan pakan yang lebih baik dalam hal FCR. Penambahan AA untuk meningkatkan pertumbuhan Thalassiosira sp. juga memberikan dampak yang menguntungkan bagi komposisi protein di seluruh tubuh udang. Secara biologis komposisi protein di tubuh udang dengan perlakuan 0,70 mg/L lebih tinggi. Hasil dari kajian ini menunjukkan bahwa penambahan nano-nutrien komersial dapat meningkatkan pertumbuhan Thalassiosira sp. dan mendorong pertumbuhan udang bada sistem budidaya di bak beton. Kata kunci: Komposisi protein, Litopenaeus vannamei, nano-nutrien, pertumbuhan, Thalassiosira sp.

The Growth and Survival of Various Forms Androgen Sex - Reversal Oreochromis niloticus Cultured Using Hapas in Concrete Tank

The production of same sex Oreochromics niloticus to enhance better and uniform growth for Tilapia culture has called for technological means using sex-reversal hormones Methyl Testosterone (MT), this study will look into the percentage growth and survival of Oreochromics niloticus fry.

PRESSURE AND STRESS ANALYSIS OF LIQUID-FILLED CYLINDRICAL TANK

During earthquakes, the liquid-filled storage tank generates hydrodynamic pressures, in addition to hydrostatic pressure, on the solid domain of the tank. The theoretical background of hydrodynamic pressure analysis, as well as the numerical simulation of the liquid-filled cylindrical concrete tank, is the focus of this paper. The Finite Element Method (FEM) modeling, along with Arbitrary Lagrangian-Eulerian and Fluid-Structure Interactions formulation, are used for simulating the seismic response of cylindrical concrete liquid-filled tank, fixed to the rigid foundation. The Loma Prieta accelerogram is utilized for recording the seismic ground motion. In the numerical study, two states are observed: 1) static condition where only hydrostatic pressure acts, and 2) seismic excitation where hydrodynamic pressure occurs. When exposed to an earthquake situation, the tank liquid gives the total pressure of the liquid domain. The dynamic analysis considers the pressure response of the liquid domain, as well as the stress response of the solid domain of the coupled system, i.e., liquid-filled cylindrical concrete tank.

Performance of Clarias gariepinus fed poultry offal meal as a replacement for fishmeal

uvenile of Clarias gariepinus (average initial weight 32.89g±0.36) were stocked at a density of 56/m2 in concrete tank and fed diets containing varying levels of poultry offal meal as partial total replacement for fish meal. The poultry offal meal was included at 0%, 10%, 20% and 40% levels of inclusion representing, 0%, 25%, 50%, 75% and 100% replacement of fish meal in the diet of the fish. Results showed that fish fed 20% level of inclusion of poultry offal meal (50%) (replacement of fish meal) had the highest average final weight/fish (104.85g) and a significantly (P<0.05) better feed conversion efficiency (0.53) than the other diets. However, fish on diet containing 40% level of inclusion of poultry offal meal (100% replacement of fish meal) had equal feed conversion efficiency (0.49) as the control and the least cost of feed per unit gain in body weight (₦0.15/g). Feed intake and live weight gain were not significantly (P>0.05) different among all dietary treatments. It is therefore established from this study that poultry offal meal; can completely replace fishmeal in the diet of Clarias gariepinus. The best overall performance was obtained at 50% replacement of fish meal with poultry offal meal.