It goes without saying that feeders should be as healthy as possible, meaning they should be properly maintained and nourished. I haven't kept a gar in many years, and I'm not sure where that info about keeping them on feeders comes from or how reliable it is. Could it possibly be referring to keeping very young gar, a couple inches long, and being forced to feed them live food...mosquito larvae, guppy fry, etc...until they grow large enough to begin training them to pellets? A 7 - 9 inch gar is young, but is still far larger than a newly-hatched one and can definitely be trained to take non-living food items.