Conversion of Koi was measured in weight of koi. Length means nothing if the fish is average, below average or above average for it's length. Also matters how accessible those fish are, whether BG or Koi..
State uses Koi because average conversion is around 4.5 to 1 and are easier to raise than BG. But, that's a very controlled situation.
If you are going to study FCR of BG, you have to establish a RW standard of the fish being eaten.
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