| There is quite some controversy and diverging opinions about feeding koi. However there are a few experiements that have been done, the one I think most revealing is the one that Thom Blishop did. The important finding, as I recall (need to find the original post :-( is that excessive feeding brings the blood sugar level up, which in turn can drive to more feeding frenzy, resulting in fat deposits, and fatty liver and kineys (not good).
Common measures among breeders and experienced koikeepers nowadays is that mature koi should get around 1-2% of weight, young koi 2% of weight, and yearlings up to 4% of weight daily of dry food (more if live or frozen, like shrimps, much higher protein contents for yearlings). This is for water temperatures at least 65°F, lower temps, less food. The koi do better if this amount is spread over 3-4 feedings a day. The optimal koi metabolic temperature is 78°F.
Some have said that koi who have a "on-demand" feeder will naturally settle to these amounts (after a "training" period of overfeeding).
I have seen yearlings eating more than 4% of weight during summer without apparent ill effect. I also have seen older koi fed too much getting way out of shape, especially in a small pond.
Right now in Oregon, the pond temperature is around 65°F in early morning and feed my koi twice a day. As the temperature rises (in the morning) I will increase food. The fact to keep in mind here is that koi take much longer to digest food at lower temperature and therefore feeding intervals should be longer (lest undigested food comes out of the fish to mess up filters and pond).
For what it's worth.
__________________
Arthur
|