1. Drug sterilization: buy birth control pills for cats and give them to female cats according to the instructions.

2. Surgical sterilization: Ask a veterinarian or an experienced farmer to perform an operation to remove the ovary or uterus.

3. Natural contraception: Try not to let the female cat contact the male cat during estrus to prevent pregnancy.

4. Contraception in vitro: Put the contraceptive ring on the female cat to prevent the male cat from contacting the female cat's genitals.