I am not trying to be argumentative Mitch, but how do you "allow" a koi to spawn and how do you forbid it from spawning? I thought you had to just take whatever is handed to you.
Do precocious koi grow up to be smaller than average? Dick thinks so. I agree.
However, it may be the frequency of spawning and the size of the spawn as well as the age at first spawning which matters. We all know that some females spawn more frequently than others and some females release a lot more eggs when they spawn than others. In my limited experience, frequent predictable spawners also tend to produce a lot of eggs. I suspect that precocious spawners are also more likely to be frequent spawners, but am even less sure of that fact.
-s