The results showed no significant different among all test diets because they contain the
same protein percentage, therefore growth, food conversion ratio and survival rate were the same .
At 25% protein level, it is enough for tilapia culture as Viwattanachaiseth (1998) has reported.
This experiment used 2 times feeding rate that was enough for tilapia culture
Viwattanachaiseth (1998) ; Chuerpohuk (1999)
This experiment has been done during October-January, while water temperature during
November-January was below 25o C. Thailand’s Department of Fisheries (1998) suggested the
optimal temperature range for tilapia culture is about 25-30o C. This temperature may effect on
growth of tilapia which seem to be slightly lower than usual , and food conversion ratios have
seem to be slightly higher than usual, because fish has to spend more energy to resist low
temperature (Whangchai, 1997) This coincide with Dan and Little (2000) who reported that tilapia
show temporary poor growth while culture in wintertime. Another water qualities of the experiment is
in the optimal range(Bhujel, 2000 ; Boyd, 1990).
From this experiment we suggested that paddy crab meal can be used as supplementary
local raw material for tilapia culture while protein percentage is 25% or more.