Baby catfish are called "sac fry" due to the small yolk sac they carry around with them which conveniently provides nourishment for the first 3 to 5 days of life.
Once it is depleted the fish naturally swim to the surface in search for food. As per Planetcatfish.com, there are several foods that can be offered to give the fry a good start. You can use micro-worm followed by newly hatched brine shrimp and then after two days you can start to introduce pre-soaked powdered flake food alternating between the two live foods.
Many farmers have been unable to successfully breed African Catfish. Several attempts made have given unfruitful results. Check out 19 proven steps to efficiently breed the African Catfish at Thefishsite.com.