Well if you have no intentions of breeding I would suggest spaying. Female cats can go into heat as early as 4 months of age. As well they will continuously go into heat around spring till early summer. The only other thing you could do is control you night and daylight time. Artificial light can trigger your females hormone level, the longer you keep on the lights the more likely she is to go in heat. If your not a breeder, planning on breeding your cats you should consider neutering and spaying. It eliminates the extra stress for your pets and yourself. My female goes into heat every other weeks until bred.

I use the light control system to keep her out of heat until the biological clock is right. If you plan to breed, talk to other breeders. They may have there males in the stud catalog for there breed registry. You can go from there. If you have any more question feel free to ask.