i just dont see how people complained about the mouse in the pirahna (sp?) tank on this forum before and how he had no way to escape but feeder foods are different.
The piranha and the mouse hting was completely different. Mammas for the most part, or even living creatures aren't on the diet of most piranhas. From what I undertand, by nature, piranhas are more of a scavenging fish not a hunter.
As for culling, I wouldn't breed if I were you then. Culling is part of responsible breeding programs. Even if you only get 20 fry out of the batch to survive. If they are deformed they should be culled. Sometimes htese fish need special requirements that many people, not even the msot expert keepers can handle.
I breed cichlids and hybrid cichlids and cull HUGE numbers. I use convicts as feeders fo my larger cichlids. You have to remember that yes, the live foods in a tank don't have as much room to get away, but do you honestly think a microworm, mosquito larvae or a brine shrimp will have any more chance of surviving in the wild? They aren't going to move all that fast then either.
To me its much better to feed as close to the natural foods the animal would eat if given the oppertunity in the wild. By nature fry are ore prone to feed off of moving targets, than ones that do not. It is in their instinct. In the wild thy eat insects off of the surface and many other things out there. If you don't consider them living things, infusoria and daphnia are really good fry foods and will get them all the way up to eating fry bites. I've never seen any kind of fry actually eat Liquifry. I've only seen itfoul up the water and jump the stats of the tank.
There are other solutions to feeding live and these have been discussed, but in some way shape or form, you are going have to think about if you could actually cull a fish if it isn't desireable to the goal you set out when you bred the fish to begin with. Do you know how many lfs carry the leftovers from people breeding bettas and refuse to cull? Many that I've come across will take all the bettas o any fish that I can't rehome.
Deformities and poor genes should be eliminated and feeding them to another fish is the best solution, this way there is no way that those weak genes can be introduced into another breeding program elsewhere. Just my $0.02 though.