They are easy to breed. The key is keeping the female safe and healthy during the whole thing.

This female corn you have; how old is she? How much does she weigh? Are you certain she is a she (as in, has she laid eggs before?) Has she been tested for parasites?

An underweight or overweight female is going to have problems with either production or laying. Breeding takes a lot out of the gals. I've had a few that lose about 1/3 of their body weight over the course of the process.