I agree w/everything that has been said about not using feeders as a regular diet, just wanted to add that especially as they grow you will want your cichlids on pellets, not flake. Hikari and NLS make very good and nutritious cichlid pellets. As a supplement, frozen foods like bloodoworms, krill, shrimp, etc. are favorites of many cichlids, and they are often enriched with vitamins.
Raising your own feeders does eliminate (or close to) the risk of disease, but as has been said, it is not healthy for your fish to eat a 100% protein diet, and even feeding healthy feeders as a primary diet is known to cause hole-in-the-head with Oscars. Plus, cichlids especially Oscars being super messy eaters to begin with, with feeders it is 10x worse - your water quality will definitely suffer even if you are doing your regular gravel vacs and water changes, which also causes hole-in-the-head.
Further, as you are seeing with your JD, many domestically bred semi-aggro cichlids aren't even really interested in feeders. They'd much rather pellets or frozen bloodworms any day. Given that, and the fact that there are far, far more nutritious foods commerically available, why would you bother to put all the effort into raising feeders? I understand it's cool to watch the predatory behavior, and occasionally feeding feeders is totally fine if they are disease-free, but to me it wouldn't be worth the effort and the risks.