• Journal of Animal Environmental Science
• /
• v.16 no.2
• /
• pp.143-152
• /
• 2010

Conditions for artificial culture of Lemna Paucicostata and its nutritional values were examined in this study. Lemna P. was cultured using artificial wastewater and a bioreactor (total volume $2,630\;cm^3$, working volume $2,240\;cm^3$) was operated at conditions of 6,250 lux and $28^{\circ}C$. Water flow affected the growth of Lemna P.: growth rate was very high (more than $1.1\;d^{-1}$) at a condition of no-water movement, but it was very low (less than $0.15\;d^{-1}$) when water moved slowly. The growth of Lemna P. was higher in $16h\;d^{-1}$ light cycle than in Sand $24h\;d^{-1}$, and it was also severely affected by the initial $NH_4$-N levels of wastewater. The growth rate of Lemna P. was high in lower $NH_4$-N level, indicating that the growth rate is in inverse proportion to $NH_4$-N concentration in wastewater. However, the contents of crude protein (CP) of Lemna P. were proportional to the initial $NH_4$-N concentration. The CP contents of Lemna P. cultured at 2, 10, 50 and 100 $NH_4$-N mg $L^{-1}$ was 18, 24, 37, 43%, respectively, showing the Lemna P. cultured at 50 and $100\;mg\;L^{-1}$ had similar protein contents to linseed (CP 35%), cottonseed (CP 38%) and soybean (CP 45%). Fat, protein, fiber, NDF and ADF contents of Lemna P. harvested at conditions of $16h\;d^{-1}$ light cycle and less than $2\;mg\;L^{-1}$ of $NH_4$-N level was 2.8, 18, 27, 20, 41 and 65.7%, respectively. Since the growth rate of Lemna P. was very high (more than $1.1\;d^{-1}$) at those conditions, it was convinced that mass production of valuable protein and fiber sources are feasible. In particular, since the Lemna P. has unsaturated fatty acids found mainly in animal fat as well as beneficial fatty acids to health such as C18:ln9c, C18:2n6c, C20:5n3 and C22:2, the Lemna P. biomass would be a highly valuable alternative feed source to grains.