RUMEN TANK AS A NOVEL TECHNIQUE FOR MORE SUSTAINABLE FISH PRODUCTION

Abd El-Naem  <https://www.facebook.com/mohamed.abdelnaem.3> F.A  Zidan, Ashraf suloma*,  Rania S Mabroke, Azab M. Tahoun, Wael El-Menofy, Mohamed H.M. El-Shafiey and Hesham R.A. Mola
1Fish Nutrition Laboratory (FNL), Animal Production Department, Faculty of Agriculture, Cairo University, 12613, Giza, Egypt
*Corresponding author: (Tel.):  + 201006176195  Email: suloma2001@agr.cu.edu.eg.

Examine the possibility of using agriculture wastes as carbon sources  instead of Molasses in biofloc technique was the motivation behind this experiment. The experiments were carried out in 9 plastic tanks with water capacity of 210L for 60 day. Tilapia juveniles with initial body weight 48.29 g were randomly distributed in the tanks at a density of 13 fish/tank (186 fish/ m2).Each group consisted of three replicates. The C:N ratio was maintained around 10:1 in water. Sufficient mixing intensity and saturated dissolved oxygen were ensured in each tank. Bio-flocs were harvested from 50 mL of tank water and biomass was collected by centrifugation (10 min, 8000 X g). DGGE based on the protocol of Muyzer et al. (1993) was performed using the Bio-Rad DCode System for DGGE. The chemical properties of water samples were determined according to APHA, 1998.

The biofloc volume recorded its highest values for fish reared using molasses as the carbon source .Treatment exposed to both Bean straw, Sugar can bagasse lead to the highest total suspended solids (TSS) values.  Ammonium values were around the  normal range for all treatments. Nitrate accumulations increased with using Sugar can bagasse as carbone source. While the lowest levels Nitrate were recorded for fish reared under bean straw. The FCR in different treatments ranged from 1.45 to 1.53. The best FCR (1.45) was observed for fish reared under Sugar can bagasse (P > 0.05). Significant difference in Final weight were observed between different treatment. the best value recorded for sugar can bagasse and bean straw with no significant different. While,weight gain values recorded no significant difference between treatments. It was proved that agricultural lignocellulosic could be used as carbone source under biofloc system without adverse effect on water quality or fish growth performance . Using biofloc pond as a rumen lead to eco-friendly application of fish culture where, system benefit from agriculture by product and environmental impact  could be avoided (Fig 1).

This work was supported by Science & Technology Development Fund (STDF), Egypt under grant no 5671.