Effect of processing fish droppings in two different ways on biofloc components

Abstract:

To study the effect of processing fish droppings in two different ways on biofloc components, two kinds of methods were used to treat the waste of eel, and then we made these wastes cultured boil-floc.The results showed that the concentration of ammonia nitrogen in the two groups decreased during the culture. The average concentration of ammonia nitrogen in the freeze-dried group was (0.86±0.22) mg/L, and the fresh group was (0.83±0.42) mg/L. After the sixth day, the concentration of nitrite nitrogen in both groups was below 0.03 mg/L. On the seventeenth day, the concentration of nitrate nitrogen in both groups was reduced to below 0.04 mg/L.The contents of crude ash in the two groups were decreased in the later stage of culture, the contents were the freeze-dried group 6.80%±0.00% and the fresh group 5.97%±0.01% respectively. The crude protein content of the freeze-dried group was 33.44%±7.80%, fresh group 33.65%±3.17%, the difference was not significant; the free amino acid type had 16 kinds in freeze-dried group, and 23 kinds in fresh group. In the fatty acids, DHA was (0.15±0.10) mg/g in the fresh group and (0.07±0.13) mg/g in the freeze-dried group.The difference was significant (P<0.05). The results show that both two treatments are suitable to cultivate floc, the freeze-dried group was good for fatty acids, and the fresh group was good for essential amino acids.