Desmianti Babo, 2016. Azolla Utilization as a Substitute Feed on the Growth of Grass Carp (Stenopharyngodon idella)
Supervisors:
Ir. Henneke Pangkey, M.Sc., Ph.D.
Dr. Erly Kaligis, S.Pi., M.Si.
SUMMARY
This study was aimed to analyze the weight and the nutritive content of azolla cultured with organic fertilizer application and without fertilizer, to analyze the response on survival rate, growth and feed conversion ratio to grass carp was given azolla feed substituting fishmeal through and examine the optimal utilization of azolla as a feed and green.
Feeding experiment was carried out in the fish pond in Tatelu, North Minahasa Regency. Culture was done for 8 weeks. Test fish were grass carps of 7.0 to 10.0 cm long and 5.00 to 10.00 grams weight, as many as 150 fish. Feed used was pellet containing 0%, 20%, 30%, 40% and 50% of azolla flour as fish meal substitute, each of which with 3 replications, while fresh azolla was given ad libitum. The study was experimental, and applied Completely Randomized Design (RAL). The responses covered survival rate, absolute growth rate, length increment, relative growth rate and feed conversion ratio. Water quality measurements included temperature, pH, and dissolve oxygen.
Results showed that azolla culture using organic fertilizer gave the best result, with weight increment of 819 grams, while the use of azolla as a substitute ingredient showed feed of 20% azolla flour content of fishmeal sustitute gave the best results. This study also found mean absolute growth of 3.23 grams, length increment of 1.20 cm, mean relative growth of 49.41%, FCR value of 4.76, and survival rate of 96.67%. The use of fresh azolla resulted inmean absolute growth of 7.19 grams, length increment of 2.37 cm, relative growth of 112.74% and 100% survival rate. Water temperatures ranged from 24.20C to 25.80C, pH was 7 and dissolve oxygen ranged from 4.7 mg/l to 6.2 mg/l. This study concluded that azolla given organic fertilizers had better growth and nutrient content. Azolla flour could also be used as an alternative feed ingredient (20%), and for operational cost saving, the use of fresh azolla for grass carp feeding at certain life stage was more efficient.