Dustin:
The only thing that I can think of that might skew the results is if the fish are conditioned to feeding on a round(ish) pellet and the feed trial pellet is worm shaped. Some fish are reluctant to change what they eat quickly.
My fish don't care. They gobble all pellets, regardless of shape. I have gone from one to the other shape and back; it made no difference that I could see.
