Growth and health performance of African catfish Clarias gariepinus (Burchell 1822) juvenile fed with graded levels of biofloc meal

The objective of the study was to evaluate the utilization of biofloc meal as a feed ingredient in enhancing the growth and health status of African catfish (Clarias gariepinus) juvenile. The study consisted of two experiments, that is digestibility and growth experiments. The digestibility of two biofloc meals produced with two different carbon sources, that is tapioca and molasses, were assessed in the digestibility experiment. Whereas the effect of four dietary treatments with different levels of biofloc meal, that is 0%, 5%, 10% and 20%, on the fish growth performance, feed utilization, immuno‐haematological response, antioxidant status and robustness against environmental stress were evaluated in the growth experiment. The results showed that the digestibility of dry matter, protein, lipid and phosphorus of biofloc grown using molasses as the carbon source were remarkably higher than that grown using tapioca (p < 0.05). The inclusion of biofloc meal in the diets at 10% and 20% resulted in higher feed intake, fish growth and final biomass and protein efficiency ratio, and lower feed conversion ratio (p < 0.05). Furthermore, the red blood cells counts, phagocytic, lysozyme activities and antioxidative capacity were significantly enhanced in the fish provided with diet containing 20% biofloc meal (p < 0.05).The fish survival following salinity stress test was higher in the treatments with biofloc meal at 10% and 20% inclusion levels. In conclusion, dietary inclusion of biofloc meal could improve the growth performance and health status of African catfish juvenile and an inclusion level of 20% could be recommended.     

Impact of transgenic sugarcane overexpressing SoSPS1 gene on bacterial diversity,enzyme activity and minerals content in soil rhizosphere

Journal of Crop Science and Biotechnology - The transgenic sugarcane overexpressing SoSPS1 gene increased sugar content which may alter the root exudation that interact with soil rhizosphere...     

Productivity assessment of an intensive whiteleg shrimp Penaeus vannamei farm based on Powersim-simulated growth rates

The main objective of intensive whiteleg shrimp Penaeus vannamei cultivation is to obtain high productivity to meet market needs. One of the efforts to boost production is to provide optimal feeding to increase the shrimp growth rate. This study analyzes the productivity of an intensive shrimp farm using Powersim simulations based on specific growth rates (SGR) and average daily growth (ADG) to determine the resulting production criteria. The cultivation lasted for 90 days by stocking 16 grow-out ponds with post-larvae (PL10) at a density of 80 PL per m². Shrimp samples were weighed every 10 days after day-30 of culture until harvest. The average productivity obtained from this study was 8.86 t/ha/crop. According to our criteria, this productivity level was low, presumably, due to the low growth rate that may have resulted from low-quality larvae, sublethal nitrite concentrations, low survival rate, and high feed conversion ratio. The SGR-based and ADG-based simulations using Powersim Studio 10 Express confirm the low production, which does not meet the criteria for intensive farming. However, ADG-based simulation shows that the prolonged culture to 126 days results in higher shrimp production and productivity that fall into the lower level of the intensive system. This study also proposes production criteria and productivity ranges for whiteleg shrimp farming.