My first batch of jag fry are about 1.5 to 2.5 inches in length. They tear up frozen cubes of blood worms like you wouldn't believe. They get a diet of small cichlid pellets, cichlid flakes and the blood worms. That seems to keep the little guys happy.
I try to stay away from feeding my larger jags minnows and other bait fish, but every once in a while it makes for good times. The other day was interesting with the hand feeding of gizzard shad (3 inches) to my breeding pair. That was the first time they ate gizzard shad. The male loves eating 3 to 4 inch Eastern Silvery Minnows I catch from the rivers.