I'm sure they were getting something else. Actually too much carbohydrates can actually hurt a fish. They don't digest it well and it can cause health problems like fatty livers especailly in bass, which is why I go to an even higher protein and less carbs for my bass. However I have hundreds of bass I feed daily in my .62 acre pond and needless to say the bluegills become scare.
I remember living in Bavaria as a kid when I was a military dependent. The local river in Bad Tolz has a river running through town called the Isar. The town had it's own pet brown trout that would come to bread thrown into the water.
